Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1990-1994  (445)
  • 1994  (445)
  • Genetics  (291)
  • crystal structure  (154)
  • 1
    Electronic Resource
    Electronic Resource
    Use of doxorubicin and dacarbazine for the management of unresectable intra-abdominal desmoid tumors in Gardner's syndrome (1994)
    Springer
    Diseases of the colon & rectum 37 (1994), S. 260-267 
    Details
    ISSN: 1530-0358
    Keywords: Desmoids ; Genetics ; Chemotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract PURPOSE: The aim of this study was to describe the natural history and management of surgically unresectable intra-abdominal desmoid tumors in two patients with Gardner's syndrome from two unrelated families, where each had failed on conventional therapy. METHODS: Two patients with Gardner's syndrome were placed on a chemotherapy regimen which included doxorubicin (90 mg/m2) and dacarbazine (900 mg/m2) in divided doses over four days of continuous infusion. Their progress on chemotherapy was assessed by abdominal computerized tomography and laparoscopy. RESULTS: The computerized abdominal tomography scans proved difficult to interpret because of adhesions and matted small bowel resulting from the patients original colectomies. These findings made it difficult to differentiate postoperative changes from residual desmoid tumor. Second-look laparotomy in such patients was contraindicated as this may predispose to further desmoid production. Laparoscopy disclosed a complete response to this chemotherapy. Nevertheless, we had an iatrogenic small bowel perforation in one of these patients. Each patient showed a complete response to chemotherapy. CONCLUSION: Surgical resection remains the first-line treatment of intra-abdominal desmoid tumors. However, doxorubicin/ dacarbazine chemotherapy on a clinical trial basis may be indicated in patients whose intra-abdominal desmoid is unresectable, or who have failed to respond to treatment with hormones (tamoxifen, Toremifene), steroids (prednisone), and nonsteroidal anti-inflammatory agents (Clinoril®; Merck & Co., Inc., West Point, PA).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02048164
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The crystal and molecular structure of N-(methylsulfonyl)-N-(2,6)-(dimethylphenyl)methanesulfonamide (1994)
    Springer
    Journal of chemical crystallography 24 (1994), S. 759-762 
    Details
    ISSN: 1572-8854
    Keywords: Sulfonamide ; methanesulfonanilide ; crystal structure ; molecular structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The title compound, crystallizes in the triclinic space group $$P\bar 1$$ witha=8.232(4),b=9.159(2),c=10.230(3)Å. α=74.07(3)°, β=72.50(4)°, γ=63.65(3)° andZ=2. The structure was solved by direct methods and refined by full matrix least squares methods toR=0.054 for 1817 observed reflections. The plane containing the nitrogen and sulfur atoms is perpendicular to the aromatic plane. One of the S−O bonds in each methanesulfonyl group is in nearly eclipsed conformation with the N−C bond.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01666966
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The crystal structure of calcium succinate monohydrate (1994)
    Springer
    Journal of chemical crystallography 24 (1994), S. 437-440 
    Details
    ISSN: 1572-8854
    Keywords: Ca(C4H4O4)·H2O ; pentagonal pyramid ; calcium succinate ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The crystal structure of calcium succinate monohydrate, Ca(C4H4O4)·H2O, has been determined by single crystal X-ray diffraction. The crystals are monoclinic witha=11.952(2),b=9.691(2),c=11.606(2)Å, β=108.81(1)°, space group C2/c,Z=8,V=1272.49 Å3,d m =1.80, andd c =1.818 Mg m−3. The structure was refined by full-matrix least-squares techniques toR=0.027,R w =0.040, for 829 reflections with1≥3δ(I). Ca is coordinated to seven oxygen atoms, and the coordination polyhedron is best described as a pentagonal bipyramid. One carboxylate group in the succinate ion is bonded to three different Ca ions, forming a four-membered chelate ring with one Ca ion is bonded to three different Ca ions, forming a four-membered chelate ring with one Ca ion and unidentate bridge bonds to two other Ca ions. The other carboxylate group is bonded to two Ca ions through unidentate bonds. The structure is highly polymeric. The general structural features are nearly identical to those of calcium adipate monohydrate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01666091
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The W2Cl4(NHCMe3)2(PR 3)2 molecules (R 3=Me3, Et3, Pr n 3, Me2Ph) I. Their isomeric forms, interconversion proeesses, crystalline forms, and detailed molecular structures (1994)
    Springer
    Journal of cluster science 5 (1994), S. 11-36 
    Details
    ISSN: 1572-8862
    Keywords: Tungsten ; isomeric forms ; crystal structure ; triple bonds ; interconversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A thorough study of compounds with the formula W2Cl4(NHCMe3)2(PR3)2, withR 3=Me3, Et3, Prg n 3 Me2,Ph, is reported. In addition to the previously reported crystalline compounds, namely Ia,trans-W2Cl4(NHCMe3)2(PMe3)2 in space group Pmmn;3a,trans-W2Cl4(NHCM3)2(PEt3)2 in space group P21/a (or P21/c); and4,cis-W2Cl4(NHCMe3)2(PMe2Ph)2 in Pna21, we have obtained and structurally characterized the following new substances,1b,trans-W2Cl4,(NHCMe3)2(PMe2)2, space group P21/c,a= 12.233 (4) Å,b= 12.872 (4) Å,c=17.095 (5) Å,β=93.52 (2)°,Z=4,V=2687 (1) Å3 2,cis-W2Cl4(NHCMe3)2(PMe3)2, P21/c,a=9.673 (4) Å,b=17.249 (4) Å,c=16.244 (5) Å,β=99.63 (3),Z = 4 ,V=2669 (1) Å.3b,trans-W2Cl4(NHCMe3)2(PEt3)2, Pl,a=16.850 (3) Å,b=17.797 (3) Å,c= 11.459 (2)Å,α= 101.02 (1),β= 103.13°, y=84.23 (1)°,Z=4,V= 3279 (1) Å5,trans-W2Cl4(NHCM3)2(PMe2Ph)2, Fdd2,a=39.563 (8) Å at 20°C; 39.325 (10) Å at -6O°C,b = 57.543 (17) Å at 20°C; 57.186 (16) Å at -60°C,c= 8.810 (1) Å at 20°C; 8.770 (1) Å at - 60°C ,Z=24,V=20057 (7) Å3 (20°C), 19723 (8) Å3 ( - 60°C) .6,trans-W2Cl4(NHCMe3 2(PPrn 3)2, Pl,a= 17.287 (2) Å (20°C); 17.077 (5) Å (-60°C),b= 19.119 (2) Å (20°C); 18.952 (6) Å (-60°C),c= 12.713 (1) Å (20°C); 12.668 (4) Å (-60°C),Z=4,V= 3980 (1) Å3 (20°C), 3898 (2) ,Å3 ( - 60°C). In addition, the structure of3a was re-determined and refined so that the disorder ratio was a refined parameter, leading to a value of 0.520:0.480 instead of being arbitrarily fixed at 0.50:0.50. In all of the structures the molecules are held in eclipsed (but very distorted) rotational conformations and the W-W distances are all within the range of 2.305-2.330 Å. As will be shown in a later paper, for all phosphines, thecis andtrans isomers are of similar stability and an equilibrium mixture exists in solution. It is also shown that1a and3a do not contain unexpectedly short W-N bonds as previously reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01165490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A new platinum-osmium alkyne complex from the reaction of Pt2Os4(CO)18 with PhC ≡ CPh: The synthesis, characterization, and crystal structure of Pt2Os4(CO)8 (μ3-PhC2Ph)3(μ4-PhC2Ph) (1994)
    Springer
    Journal of cluster science 5 (1994), S. 317-326 
    Details
    ISSN: 1572-8862
    Keywords: Mixed metal cluster ; alkyne ; diphenylacetylene ; platinum ; osmium ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The new platinum-osmium alkyne cluster complex Pt2Os4(CO)8(μ3-PhC2Ph)3 (μ 4-PhC2Ph),2, was obtained from the reaction of Pt2Os4(CO)18,1b, with PhC2Ph and was characterized by IR.1H NMR and single-crystal X-ray diffraction analyses. The cluster of compound2 consists of an osmium capped Pt2Os3 square pyramid. It aLso contains three triply bridging and one quadruply bridging diphenylacetylene ligands. Crystal data for2: space group PI,a = 12.530(2) Å,b = 21.565(4) Å,c = 11.284(2) Å,α = 100.31(2),β = 111.89(1),β = 76.78(2),Z = 2, 3879 reflections,R = 0.032.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01170715
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Synthesis, structure and IR characterization of disodium tetra(9,10-dihydro-9-oxo-10-acridineacetato)zincate(II) bis(ethanol) heptahydrate (1994)
    Springer
    Journal of chemical crystallography 24 (1994), S. 731-737 
    Details
    ISSN: 1572-8854
    Keywords: Synthesis ; crystal structure ; IR data
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The synthesis, crystal structure and IR data are reported for Na2[Zn(CMA)4]·2EtOH·7H2O, where CMA− is the 9,10-dihydro-9-oxo-10-acridinacetate ion. The complex crystallizes in the monoclinic space group P2/n, with cell dimensionsa=17.335(9),b=8.440(5),c=21.875(12) Å, β=91.94(5)°,Z=2. The structure was solved by direct methods and refined to a finalR value of 0.0363 for 3022 non-zero reflections. The Zn2+ ion occupies twofold axis and is coordinated to four carboxylate ligands, the ZnO4 tetrahedron is considerably distorted with Zn−O distances of 1.978(3) and 1.961(3)Å. Each Na+ cation interacts with two water, one ethanol, and three carboxylate O atoms comprising distorted octahedron. The Zn2+ and Na+ cations are linked through monooxygen and syn-syn carboxylate bridges forming a trinuclear, mixed-metal cluster. The Zn...Na separation is 3.267(2)Å and Na...Na distance equals 3.520(2)Å. All oxygen bonded H-atoms are utilized in hydrogen bonds. The acridone rings overlap in the crystal with the 3.5 Å interlayer separations. The compound has been characterized by IR spectroscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01666961
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Synthesis, characterization, and crystal structure of 1,3,7,9-tetramethylpyrido-[2,3-d∶6,5-d′]-dipyrimidine-2,4,6,8-tetrone (1994)
    Springer
    Journal of chemical crystallography 24 (1994), S. 465-468 
    Details
    ISSN: 1572-8854
    Keywords: Pyrimidine ; uracil ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A new and easy method for the preparation of 1,3,7,9-tetramethylpyrido-[2,3-d∶6,5-d′]-dipyrimidine-2,4,6,8-tetrone is described. The structure of this compound has been solved by means of X-ray diffraction methods. The chemical characterization by spectral (mass, ultraviolet, infrared, and proton nuclear magnetic resonance) and thermal (thermogravimetry and differential scanning calorimetry) method is also reported. The compound is monoclinic, space groupP21/c,a=12.720(5),b=13.688(7),c=8.079(2) Å, β=107.06(4)°,Z=4. The structure consists of discrete tricyclic molecules, stacking playing an important role in crystal packing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01666096
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Crystal structure oftrans-carbonylchlorobis-(tricyclohexylphosphine)iridium(I),trans-Ir(CO)Cl-[P(cyclo-C6H11)3]2, a disordered species (1994)
    Springer
    Journal of chemical crystallography 24 (1994), S. 557-560 
    Details
    ISSN: 1572-8854
    Keywords: Centrosymmetric ; symmetry ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The title compound crystallizes in the centrosymmetric triclinic space group $$P\bar 1$$ (C 1 l ; No.2) witha=9.9143(10) Å,b=10.2616(11) Å,c=10.7715(10) Å, α=113.887(8)°, β=109.197(8)°, γ=90.699(9)°,V=932.78(17) Å3 andZ=1. A total of 4869 data were collected and merged to a set of 2450 independent reflections; the structure was solved and refined toR=1.42% andwR=1.94%. The molecule lies on a site of $$\bar 1$$ symmetry and is disordered, with obvious scrambling of carbonyl and chloride ligands. Resulting bond lengths include Ir−P=2.339(1) Å, Ir−Cl=2.398(4) Å and Ir−CO=1.808(15) Å.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01666737
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The synthesis and structural analysis of the new high nuclearity platinum-ruthenium cluster complex Pt2Ru8(CO)18(μ3−EtC2Et)2(μ4−EtC2Et) containing three alkyne ligands (1994)
    Springer
    Journal of cluster science 5 (1994), S. 551-564 
    Details
    ISSN: 1572-8862
    Keywords: Mixed metal ; platinum ; ruthenium ; alkyne ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstarct The ten metal cluster complex Pt2Ru8(CO)23(µ3−H)2, 1 was found to react with EtC2Et to form a new ten metal tris-alkyne complex Pt2Ru8(CO)18(µ3−EtC2Et)2 (µ4−EtC2Et),2 in 35% yield. Complex 2 was characterized by IR,1H NMR , and single crystalx-ray diffraction analyses. The cluster can be viewed as a dodecahedron of eight metal atoms capped with two ruthenium carbonyl groups, two triply bridging EtC2Et ligands and one quadruply bridging EtC2Et ligand. Application of the standard electron counting procedures indicate that this is an unusual complex in which the 18 electron rule applies and the polyhedral skeletal electron pair theory does not. Crystal Data for 2 2.0.5 CH2CI2: space group = P21,a = 12.759(2) A,b=18.438(2)Å,c = 20.197(3) Å,β = 91.59(1)°, Z. = 4, 6394 reflections,R = 0.037.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01171385
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Genetic ecology: A new interdisciplinary science, fundamental for evolution, biodiversity and biosafety evaluations (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 429-437 
    Details
    ISSN: 1420-9071
    Keywords: Genetics ; ecology ; DNA-transfer ; conjugation ; transformation ; transduction ; transposons ; dormant cells ; epilithon ; microbial colonisation ; symbiosis ; virus resistance ; biosafety ; release of genes ; insults to humanity ; evolution ; biodiversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Genetic ecology is the extension of our modern knowledge in molecular genetics to studies of viability, gene expression and gene movements in natural environments like soils, aquifers and digestive tracts. In such milieux, the horizontal transfer of plasmid-borne genes between phylogenetically distant species has already been found to be much more frequent than had been expected from laboratory experience. For the study of exchanges involving chromosomally-located genes, more has to be learned about the behaviour of transposons in such environments. The results expected from studies in genetic ecology are relevant for considerations of evolution, biodiversity and biosafety. The role of this new field of research in restoring popular confidence in science and in its biotechnological applications is stressed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01920741
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    HLA class II genes and antibodies against recombinant U1-nRNP proteins in patients with systemic lupus erythematosus (1994)
    Springer
    Rheumatology international 14 (1994), S. 63-69 
    Details
    ISSN: 1437-160X
    Keywords: Systemic lupus erythematosus ; Recombinant U1-nRNP proteins ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To investigate a possible involvement of HLA-class II alleles in the genetic predisposition for the formation of anti-U1-nRNP antibody in systemic lupus erythematosus (SLE), genomic DNA of 178 patients was typed for the DRB1, DQA1 and DQB1 alleles using a polymerase chain reaction (PCR) and non-radioactive-oligonucleotide typing. Antibodies against recombinant U1-nRNP proteins (U1-A- U1-C-and 70K-protein) were determined by ELISA. Anti-U1-C antibody was found in 26 (14.7%), anti-U1-A in 34 (19.2%) and anti-70K in 17 (9.6%) patients. A joint occurrence was observed for these antibodies against the recombinant U1-nRNP proteins: anti-U1-C and anti-U1-A antibodies occurred together more frequently than alone and than together with anti-U1-70K antibodies. The frequency of DRB1 * 04 was slightly increased in the patients with anti-U1-C as compared to the patients without anti-U1-C (P〈0.05, Pcorr=n.s., RR=2.4). The DQA1 * 0301 allele, which is in linkage disequilibrium with DRB1 * 04, is found more frequently in anti-U1-C-positive than in antibody-negative patients. The DQB1 * 0303 allele, detected in 12 of 176 SLE patients, was absent in the patients with any of the antibodies against the U1-nRNP proteins. All these deviations may be due to chance alone. We concluded that the presence of antibodies against recombinant U1-nRNP proteins was not significantly associated with any HLA DRB1, DQA1 and DQB1 allele in our group of SLE patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300249
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Studies of crystalline native celluloses using potential energy calculations (1994)
    Springer
    Cellulose 1 (1994), S. 161-168 
    Details
    ISSN: 1572-882X
    Keywords: cellulose I ; molecular mechanics ; crystal structure ; molecular ; modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Energies for various trial packing arrangements of unit cells for the Iα and Iβ phases of native cellulose discovered by Sugiyamaet al. were evaluated. Both a rigid-ring method, PLMR, and the full-optimization, molecular mechanics program, MM3(90), were used. For both phases the models that had the lowest PLMR energy also had the lowest MM3 energy. Both calculated models have the chains packed ‘up’, O6s intg positions, and the same sheets of hydrogen-bonded chains. The Iβ structure model is essentially identical to that proposed previously for ramie cellulose by Woodcock and Sarko. It is also the same as the best parallel model previously proposed that was based on the X-ray data of Mann, Gonzalez and Wellard, once the various unit cell conventions are considered. Also, the energies from both methods for all three celluloses, Iα, Iβ and II, are in the order that rationalizes their relative stabilites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00819665
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Myotonic dystrophy and limb girdle muscular dystrophy in one family (1994)
    Springer
    Journal of molecular medicine 72 (1994), S. 409-413 
    Details
    ISSN: 1432-1440
    Keywords: Myotonic dystrophy ; Limb girdle muscular dystrophy ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A family is reported in which a 29-year-old woman showed the clinical features of myotonic dystrophy while her 26-year-old brother presented with the clinical picture of limb girdle syndrome. In the affected female, direct genetic testing for the specific myotonic dystrophy mutation on chromosome 19 revealed abnormal expansion of a repeat unit containing the three nucleotides cytosine, thymine, and guanine (CTG) — typical for myotonic dystrophy — while her diseased brother displayed two normal alleles. This supports the hypothesis of the extremely rare occurrence of two clinically and genetically different myopathies in one family. Genetic analysis of six other family members showed that the father of the diseased siblings as well as all of his three brothers and sisters had a pathological CTG repeat expansion, and that the other two family members tested had a normal allelic pattern. The number of CTG repeats in the diseased women was approximately tenfold higher than in her asymptomatic relatives who revealed an abnormal allelic pattern. The increase in CTG repeats with transmission to a subsequent generation in this family was paralleled by a dramatic increase in the severity of myotonic dystrophy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00252840
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Superconductivity in the tetragonal phase of La1.9Bi0.1CuO4+δ annealed under high oxygen pressure (1994)
    Springer
    Journal of superconductivity 7 (1994), S. 37-38 
    Details
    ISSN: 1572-9605
    Keywords: High-Tc superconductivity ; La1.9Bi0.1CuO4+δ ; excess oxygen ; crystal structure ; superconducting transition temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We have investigated the relation between the crystal structure and superconductivity in La1.9Bi0.1CuO4+δ , in which the phase separation observed in La2CuO4+δ is suppressed. A phase diagram in theT−δ plane is given for La1.9Bi0.1CuO4+δ with excess oxygen. For very smallδ values, the crystal structure is orthorhombic, and an orthorhombic-tetragonal phase transition occurs markedly atδ ∼ 0.03 in the measured temperature range between 13 and 293 K. Superconductivity is observed in the range of 0.04〈δ〈0.11. This is clear evidence thathigh-T c superconductivity also appears in the tetragonal phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00730364
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Mixed desmoplastic primitive neuroepithelial tumor of infancy: a light microscopic, immunocytochemical, ultrastructural and genetic study (1994)
    Springer
    Acta neuropathologica 89 (1994), S. 99-104 
    Details
    ISSN: 1432-0533
    Keywords: Key words     Primitive neuroepithelial tumor ; Desmoplastic small cell tumor ; Brain tumor of infancy ; Immunocytochemistry ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract      We describe a case of a desmoplastic brain tumor which was initially resected from the right fronto-temporal region in a 2 year-old boy. This nodular, calcified tumor was vascularized by the internal carotid artery and the middle meningeal artery branches. Grossly, it contained several mucoid cysts. Light microscopy showed cords or nests of small cuboidal cells surrounded by a loose connective tissue and desmoplasic areas containing fibers and spindle cells. The cuboidal cells expressed epithelial, neuronal and neuroendocrine markers. Some foci of spindle cells showed glial differentiation. The tumor recurred 16 months later and displayed some characteristics of the small cell neuroepithelial component, mitoses being conspicuous. Electron microscopy revealed undifferentiated clear cells, some containing neurosecretory granules. Karyotyping demonstrated the following formula: 〈 15 〉 46, t(8;11) (q13; q11). The chromosome 11 breakpoint was different from that described in Ewing's sarcoma. This isolated translocation has not been previously reported to our knowledge. These unusual features lead us to report this case and to discuss its pathogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050221
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Familial amyotrophic lateral sclerosis with a mutation in the Cu/Zn superoxide dismutase gene (1994)
    Springer
    Acta neuropathologica 88 (1994), S. 185-188 
    Details
    ISSN: 1432-0533
    Keywords: Amyotrophic lateral sclerosis ; Neuropathology ; Posterior column involvement ; Genetics ; Superoxide dismutase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Several missense mutations within exons 1, 2, 4 and 5 of the gene for Cu/Zn-binding superoxide dismutase (SOD1) have been discovered to be involved in the development of chromosome 21q-linked familial amyotrophic lateral sclerosis (FALS). We describe here an autopsied patient with FALS, in whom we have recently identified a novel missense mutation in exon 1 of the SOD1 gene. The neuropathological findings were compatible with those described previously in patients with FALS with posterior column involvement. This suggests that mutations of the SOD1 gene may be responsible for this form of FALS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294513
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Familial amyotrophic lateral sclerosis with a mutation in the Cu/Zn superoxide dismutase gene (1994)
    Springer
    Acta neuropathologica 88 (1994), S. 185-188 
    Details
    ISSN: 1432-0533
    Keywords: Key words: Amyotrophic lateral sclerosis ; Neuropathology ; Posterior column involvement ; Genetics ; Superoxide dismutase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Several missense mutations within exons 1, 2, 4 and 5 of the gene for Cu/Zn-binding superoxide dismutase (SOD1) have been discovered to be involved in the development of chromosome 21q-linked familial amyotrophic lateral sclerosis (FALS). We describe here an autopsied patient with FALS, in whom we have recently identified a novel missense mutation in exon 1 of the SOD1 gene. The neuropathological findings were compatible with those described previously in patients with FALS with posterior column involvement. This suggests that mutations of the SOD1 gene may be responsible for this form of FALS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294513
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Problems in the low-temperature synthesis of 92K Superconducting YBCO (1994)
    Springer
    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1671-1678 
    Details
    ISSN: 0392-6737
    Keywords: Effects of material synthesis ; crystal structure ; chemical composition ; Y-based compounds ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary YBCO with high granulometric perfection and low dispersion can be obtained by a low-temperature reaction (≈800°C) of atomic-scale dispersed powders, produced through the thermal decomposition of liquid precursors. As reacted such powders are tetragonal and not superconducting, but they transform into the high-T c phase after optimized annealing treatments. We describe the method we developed and the characteristics of the materials we achieved, and we discuss the main features of the process in the light of the current know-how.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02462158
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Mitochondrial gene defects in patients with NIDDM (1994)
    Springer
    Diabetologia 37 (1994), S. 372-376 
    Details
    ISSN: 1432-0428
    Keywords: Genetics ; diabetes mellitus ; mitochondria ; maternal ; deafness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Non-insulin-dependent diabetes mellitus (NIDDM) has a strong genetic component and maternal factors have recently been implicated in disease inheritance. The mitochondrial myopathies are a group of diseases which often show maternal inheritance as a result of mtDNA defects; some patients have impaired glucose tolerance. Occasional families with maternally inherited diabetes and deafness associated with a deletion or point mutation of mtDNA have been reported. To assess the importance of mitochondrial gene defects in NIDDM, 150 unrelated diabetic subjects from Wales, UK and 68 unrelated patients with diabetes and at least one affected sibling from England, UK were studied. Southern blot analysis did not show any large mtDNA deletions or duplications. One patient had a mutation in the mitochondrial tRNAleu(UUR) gene at bp 3243. This mutation is commonly associated with the syndrome of mitochondrial encephalomyopathy, lactic acidosis and stroke like episodes (MELAS). Study of this patient and his siblings showed a distinct form of late-onset diabetes associated with nerve deafness but no clinical features of the MELAS syndrome. No diabetic subject was shown to have the mtDNA mutation at position 8344 (tRNAlys) which has previously been described in the syndrome of mitochondrial encephalomyopathy and red-ragged fibres (MERRF). The role of other mitochondrial gene defects in diabetes and the pathophysiological basis of glucose intolerance in patients with the MELAS mutation requires further elucidation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00408473
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Renal eicosanoids and blood pressure in genetically hypertensive rats of the lyon strain (1994)
    Springer
    Journal of biomedical science 1 (1994), S. 201-203 
    Details
    ISSN: 1423-0127
    Keywords: Hypertension ; Eicosanoid ; Rat ; Genetics ; Kidney
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The present paper reviews the evidence for a possible involvement of renal eicosanoids in the pathophysiology of high blood pressure in genetically hypertensive rats of the Lyon strain. Both in vivo and in vitro experiments suggest that an increased ability to synthesize the vasoconstrictor prostaglandin H2 and/or thromboxane A2 in renal vessels (1) acts as an autocrine amplifier of pressor agents and (2) may contribute to resetting the pressure natriuresis curve which is a prerequisite for the development and maintenance of hypertension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02253302
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    A gene in the HLA class I region contributes to susceptibility to IDDM in the Finnish population (1994)
    Springer
    Diabetologia 37 (1994), S. 937-944 
    Details
    ISSN: 1432-0428
    Keywords: Genetics ; haplotype ; HLA-A ; HLA-DQ ; HLA-DR ; tumour necrosis factor ; diabetes mellitus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In Finland the haplotype A2, Cw1, B56, DR4, DQ8 is the third most common haplotype in insulin-dependent diabetic (IDDM) patients and has the highest haplotype-specific absolute risk for IDDM. Cw1, B56, DR4, DQ8 haplotypes containing HLA-A alleles other than A2 are infrequent in the population and are not associated with IDDM. Comparison of the A2 and non-A2 haplotypes at the DNA level showed that they were identical at HLA-B,-DR, and -DQ loci. Evidence that class I alleles confer susceptibility to IDDM was obtained from the two HLA-C, -B, -DR and -DQ haplotypes most frequently found in IDDM patients in Finland. A24, A3 and A2 on the Cw3, B62, DR4, DQ8 haplotype, and A28, A2 and A1 on the Cw7, B8, DR3, DQ2 were all found to be associated with IDDM. In Finland these seven haplotypes, including A2, Cw1, B56, DR4, DQ8, account for 33% of diabetic haplotypes and 10.3% of non-diabetic haplotypes (p〈0.00001). The contribution of the class I region to IDDM susceptibility was also apparent in those IDDM patients lacking the disease-predisposing class II alleles. Significantly more non-DR3/non-DR4 IDDM patients (47 of 55) possessed two of the IDDM-associated HLA-A alleles compared to non-DR3/non-DR4 control subjects (40 of 58; p=0.038). Moreover, IDDM patients confirmed by oligotyping as unable to form a ‘diabetes-susceptibility’ DQ heterodimer, tended to possess two diabetes-associated HLA-A alleles (12 of 13) compared to control subjects (12 of 20; p=0.056).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00400951
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Familial occurrence of discrete subaortic membrane (1994)
    Springer
    Pediatric cardiology 15 (1994), S. 198-200 
    Details
    ISSN: 1432-1971
    Keywords: Subaortic stenosis ; Congenital heart disease ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The first case of multiple family members with discrete subaortic membrane and no other congenital defects is presented. One family member presents with findings suggesting a forme fruste of this disease. Increased surveillance of family members of individuals with discrete subaortic membrane is warranted, as the clinical findings of mild subaortic obstruction may be indistinguishable from those of an innocent flow murmur.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00800675
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Tricuspid atresia and annular hypoplasia: Report of a familial occurrence (1994)
    Springer
    Pediatric cardiology 15 (1994), S. 201-203 
    Details
    ISSN: 1432-1971
    Keywords: Tricuspid atresia ; Tricuspid hypoplasia ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Occurrence of a similar cardiac malformation in multiple family members has been reported for many lesions. Neither tricuspid atresia nor tricuspid annular hypoplasia and tricuspid atresia and one case of tricuspid annular hypoplasia with an atrial septal defect in siblings. The findings in this family suggest an autosomal recessive pattern of inheritance for abnormal tricuspid valve morphogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00800676
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Genetic analysis of a polyembryonic mutant in rye (1994)
    Springer
    Sexual plant reproduction 7 (1994), S. 290-296 
    Details
    ISSN: 1432-2145
    Keywords: Secale cereale ; Polyembryony ; Chromosome mosaics ; Rye ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have obtained one plant regenerated from rye tissue culture which showed a high percentage of polyembryonic seeds in its progeny. The mutation inducing the development of extra embryos is also influencing erroneous cell division, mitosis and meiosis. The genetic analysis indicated that the aptitude for polyembryonic seed formation is a heritable trait controlled by a dominant gene. However, for expression of the phenotype the female parent should have a specific cytoplasm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227712
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Absence epilepsy of early childhood —genetic aspects (1994)
    Springer
    European journal of pediatrics 153 (1994), S. 372-377 
    Details
    ISSN: 1432-1076
    Keywords: Epilepsy ; Absences ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Clinical and EEG family data of 140 cases with early childhood epilepsy with absences are presented. The aim of the study was to evaluate, whether the occurrence of generalized tonic clonic seizures (GTCS) as a presenting symptom might correlate with family data, i.e. whether there are indications of heterogeneity. One hundred and forty cases were selected from the epilepsy family data base of the Neuropaediatric Department. The selection parameter was epilepsy with absences manifesting between the 1 st and 5th year of age. The incidence of seizures was evaluated in siblings, parents and parents' siblings. EEG records were available from 103 parents and 106 siblings. The analysis supports the assumption of heterogeneity within early childhood absence epilepsy. Parents and their sibs of cases manifesting with GTCS had seizures twice as often than parents and their sibs in the non-GTCS group. In the affected relatives of the GTCS group early onset GTCS prevailed, whereas in the relatives of the non-GTCS group absences were found more frequently. The EEG of relatives showed elevated incidences of spikes and waves and photosensitivity in both groups, indicating common genetic factors. In parents of the non-GTCS group, however, EEG pathology was significantly more frequent than in parents of the GTCS group. Comparing EEG pathology in parents with seizure risk in siblings, evidence for maternal preponderance in transmission of the seizure liability was found. Mothers' EEG seems to be the best predictor of the seizure risk in probands' siblings. Early childhood epilepsy with absences can be regarded as an intermediate type, showing overlap with early onset GTCS and myoclonic astatic epilepsy on the one side and with childhood absence epilepsy on the other.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01956423
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Multiple sclerosis: genetic versus environmental aetiology: epidemiology in Israel updated (1994)
    Springer
    Journal of neurology 241 (1994), S. 341-346 
    Details
    ISSN: 1432-1459
    Keywords: Multiple sclerosis Epidemiology ; Immigrants Environment ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The incidence and prevalence of multiple sclerosis (MS) were compared, controlling for age, in native-born Israelis of different origins and in immigrants to Israel. This comparison was carried out in two populations, countrywide and in Jerusalem. In the countrywide population, ascertainment was based mainly on hospitalizations; it included 252 patients who were native-born and 150 who had immigrated from Africa-Asia (AA immigrants). The 89 MS patients of Jerusalem also included patients diagnosed in outpatient clinics. In native-born Israelis whose father was born in Europe-America (I-EA), the incidence and prevalence of MS were found to be as high as or even higher than that found previously in immigrants from Europe-America. Among native-born Israelis whose father was born in Africa or Asia (I-AA), the yearly age-adjusted incidence and prevalence rates were found to be 1.4- to 1.8-fold higher than among AA immigrants, pointing to environmental factors. The incidence and prevalence rates in the I-EA were 1.2- to 1.6-fold higher than in the I-AA, pointing to genetic factors. These results seem to point to both environmental and genetic factors in the aetiology of MS. Further research is needed, however, to disentangle the genetic factors from possible environmental differences in the two ethnic groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00868444
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Follow-up and family study of postpartum psychoses (1994)
    Springer
    European archives of psychiatry and clinical neuroscience 244 (1994), S. 138-140 
    Details
    ISSN: 1433-8491
    Keywords: Parity ; Genetics ; Diathesis-stress model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract As part of a follow-up and family study of post-partum psychoses, this episode of illness being the first leading to psychiatric hospitalisation, patients with puerperal episodes (PE) and nonpuerperal episodes (NPE) of illness in the long-term course (n=79) were compared to patients with PE only (n=40). Few differences were found. Relatives of patients with PE only had a lower morbidity risk for functional psychoses than relatives of patients with PE and NPE. A favourable course of illness in the presence of a low genetic predisposition may be expected, according to the diathesis-stress model of functional psychoses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02191888
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Clinical and genetic aspects of juvenile absence epilepsy (1994)
    Springer
    Journal of neurology 241 (1994), S. 487-491 
    Details
    ISSN: 1432-1459
    Keywords: Juvenile absence epilepsy ; Valproate ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Fifteen patients aged 11–25 years (mean 15.37, SD 3.89) suffering from juvenile absence epilepsy are presented. Only 3 (20%) had absences (AS) as the only seizure type, 12 (80%) had associated generalized tonic-clinic seizures (GTCS) and in the remaining 3 with absences and GTCS there was also sporadic myoclonus. We found a higher frequency of AS in our patients by clinical history and video-EEG than has been previously reported. In our patients the mean age of onset in years was 11.4, SD 1.24 for AS, 13.12, SD 2.31 for GTCS and 12.5, SD 2.18 for myoclonus. The correct diagnosis was not made on referrals for any of the patients. It took an average of 3–5.5 years from the onset of the AS (range: 6–120 months) and 2 years from the occurrence of GTCS (average: 1–72 months) to make the correct diagnosis and institute proper treatment, which was valproic acid (VPA). The GTCS were controlled in all patients whereas AS continued in 6 (40%), but to a significantly lesser degree. The frequency and the duration of the GTCS before the start of VPA treatment seemed to have an adverse effect on AS control. We documented no circadian rhythm in either AS or the GTCS, except in 2 patients who had AS and GTCS mainly when they awoke in the morning. The sample size was too small to perform a proper genetic study, though a positive history of epilepsies of mixed types was obtained in 35.7% of the parents and the siblings of the probands.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00919710
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Preparation and characterization of some metal(II) complexes of isocinchomeronic acid and X-ray crystal structure ofcis-diaquabis(hydrogen isocinchomeronato)manganese(II) (1994)
    Springer
    Structural chemistry 5 (1994), S. 165-170 
    Details
    ISSN: 1572-9001
    Keywords: Isocinchomeronic acid ; 2,5-pyridinedicarboxylic acid ; hydrogen isocinchomeronate ; manganese(II) complex ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The reactions between Mn(II), Co(II), Ni(II), and Zn(II) ions with isocinchomeronic acid (H2-isocin) afforded complexes of the general formula M(H-isocin)2-2H2O, whereas Fe(II) gives both red and deep red-brown products of the same formula. Various physical measurements suggest that the complexes of M = Co, Ni, Zn, and Fe (brown) are octahedrally coordinated by two aqua ligands and twotrans-N,O-bidentate H-isocin− anions with dimeric hydrogen bonding. Those for M = Mn and Fe (red) are the correspondingcis isomers. The structure of the manganese complex as determined by X-ray crystallography exhibitsC 2 molecular symmetry with Mn-N = 2.279(2), Mn-O(H-isocin)− = 2.196(2), and Mn-O(aqua) = 2.137(2) Å. Each aqua ligand forms two donor O-H ⋯ O hydrogen bonds with carboxy groups of different molecules in adjacent chains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02262837
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Tris(pyrazol-1-yl)-s-triazine (TPT): X-ray crystallographic, computational, and gas-phase electron diffraction studies (1994)
    Springer
    Structural chemistry 5 (1994), S. 255-264 
    Details
    ISSN: 1572-9001
    Keywords: tris(pyrazol-1-yl)-s-triazine ; crystal structure ; electron diffraction ; AM1 semiempirical calculation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The conformation of the TPT molecule has been analyzed using experimental and computational techniques. The solid-state molecular structure shows similar conformational features to those in the 2-pyrimidine and phenyl derivatives although a different pattern of bond angles in the triazine ring was observed. The AM1 calculations predicted two conformations of comparable stability (ΔE=1.8 kcal/mol) differing in the orientation of one pyrazole ring. While the minimum energy conformation corresponds to a model displayingC 3h symmetry (φ 1=φ 2=φ 3=0°), the other minimum (φ 1=φ 2=0°,φ 3=180°) is close to that observed in the solid state. The electron diffraction results are consistent with a planar or nearly planar conformation in agreement with the preceding studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02275498
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Structure of TiO2 in TiO2-SiO2 prepared by a complexing agent-assisted sol-gel procedure (1994)
    Springer
    Journal of sol gel science and technology 1 (1994), S. 113-121 
    Details
    ISSN: 1573-4846
    Keywords: crystal structure ; complexing agent ; TiO2 ; TiO2-SiO2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Many types of TiO2-SiO2 (Ti:Si=50:50 mol%) were prepared by the sol-gel procedure with and without 2-methyl-2, 4-pentanediol (MPD) as an organic ligand. The effect of MPD on the gel structure and the properties of the TiO2 crystals were studied by XRD and raman spectroscopy, and the effect of the sol standing time on the properties of the TiO2 crystals were also studied by XRD spectroscopy. In the gels with MPD, anatase of TiO2 appeared at approximately 580°C, and the crystal structures were similar despite the difference in the gel preparation procedure. The titania gels with MPD were presumed to be dispersed in the silica gel matrix without any Ti-O-Si bond. In the presence of MPD, the formation of titania gels is controlled and the specified TiO2 crystal is produced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00490241
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Molecular marker-facilitated studies in an elite maize population: I. Linkage analysis and determination of QTL for morphological traits (1994)
    Springer
    Theoretical and applied genetics 88 (1994), S. 7-16 
    Details
    ISSN: 1432-2242
    Keywords: Maize ; Restriction fragment length polymorphisms (RFLPs) ; Qualitative and quantitative inheritance ; Plant breeding ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Restriction fragment length polymorphisms (RFLPs) and one morphological marker were used to investigate quantitative trait loci (QTL) for morphological and physiological traits evaluated on 150 F2∶3 maize (Zea mays L.) lines derived from the cross of elite U.S. Corn Belt inbreds Mo17 and H99. F2∶3 lines were grown in a replicated experiment and evaluated for plant and ear heights and flowering traits. QTL were identified for each trait, and genetic effects were determined. Estimated gene action for the flowering traits was predominantly overdominance. Both parents contributed toward increased values for anthesis and silk emergence. QTL for increased plant and ear heights were usually contributed by the taller parent, Mo17. Estimated gene action for these traits was mainly partial to overdominance. QTL for plant height were located in the vicinity of loci defined by alleles with qualitative effects on plant height.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222387
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Chromosome assortment in Saccharum (1994)
    Springer
    Theoretical and applied genetics 89 (1994), S. 959-963 
    Details
    ISSN: 1432-2242
    Keywords: Sugarcane ; Polyploidy ; Genetics ; Evolution ; Breeding ; DNA markers ; Arbitrarily primed PCR ; RAPD markers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recent work has revealed random chromosome pairing and assortment in Saccharum spontaneum L., the most widely distributed, and morphologically and cytologically variable of the species of Saccharum. This conclusion was based on the analysis of a segregating population from across between S. spontaneum ‘SES 208’ and a spontaneously-doubled haploid of itself, derived from anther culture. To determine whether polysomic inheritance is common in Saccharum and whether it is observed in a typical biparental cross, we studied chromosome pairing and assortment in 44 progeny of a cross between euploid, meiotically regular, 2n=80 forms of Saccharum officinarum ‘LA Purple’ and Saccharum robustum ‘ Mol 5829’. Papuan 2n=80 forms of S. robustum have been suggested as the immediate progenitor species for cultivated sugarcane (S. officinarum). A total of 738 loci in LA Purple and 720 loci in Mol 5829 were amplified and typed in the progeny by arbitrarily primed PCR using 45 primers. Fifty and 33 single-dose polymorphisms were identified in the S. officinarum and S. robustum genomes, respectively (χ 2 at 98%). Linkage analysis of single-dose polymorphisms in both genomes revealed linkages in repulsion and coupling phases. In the S. officinarum genome, a map hypothesis gave 7 linkage groups with 17 linked and 33 unlinked markers. Four of 13 pairwise linkages were in repulsion phase and 9 were in coupling phase. In the S. robustum genome, a map hypothesis gave 5 linkage groups, defined by 12 markers, with 21 markers unlinked, and 2 of 9 pairwise linkages were in repulsion phase. Therefore, complete polysomic inheritance was not observed in either species, suggesting that chromosomal behavior is different from that observed by linkage analysis of over 500 markers in the S. spontaneum map. Implications of this finding for evolution and breeding are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224524
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Genetic analysis of tolerance for phosphorous deficiency in rice (Oryza sativa L.) (1994)
    Springer
    Theoretical and applied genetics 89 (1994), S. 313-317 
    Details
    ISSN: 1432-2242
    Keywords: Genetics ; Rice ; Phosphorousefficiency ; Diallel analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The inheritance of phosphorous (P) — deficiency tolerance in rice was investigated by a sevenparent diallel. The parent materials involved were four P-efficient (IR20, IR54, IR28, and Mahsuri), one moderately P-efficient (TN1), and two P-inefficient (IR31406333-1 and IR34686-179-1-2-1), genotypes. Relative tilering ability (RTA) under P-deficient and P-supplemented soil conditions was the parameter used in determining the tolerance level of the different genotypes. Diallel graph analysis revealed that tolerant parents have an excess of recessive genes, while moderate and susceptible parents possess more dominant genes. Genetic-component analysis suggested that both additive and dominance gene effects are involved in the inheritance of P-deficiency tolerance in rice. The trait exhibited over doiminance as confirmed by the graphical analysis. Narrow-sense heritability of the trait was moderate (0.50) and environmental effects were low. Both the general combining ability (GCA) and the specific combining ability (SCA) were significant, but GCA was more prevalent than SCA. Tolerant parents exhibited a high GCA whereas susceptibles have a very poor GCA, suggesting that tolerant parents were mostly enriched in additive genes and susceptible parents in non-additive genes. Crosses involving two high general combiners showed low SCA effects whereas crosses between poor general combiners manifested highly-significant SCA values.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225160
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Resistance to potato leaf roll virus multiplication in potato is under major gene control (1994)
    Springer
    Theoretical and applied genetics 88 (1994), S. 754-758 
    Details
    ISSN: 1432-2242
    Keywords: Potato breeding ; Potato leaf roll virus ; Virus resistance ; Major gene resistance ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The concentration of potato leaf roll virus (PLRV), as measured by a quantitative enzyme-linked immunosorbent assay, in the foliage of potato plants (Solanum tuberosum) of cv ‘Maris Piper’ with secondary infection was 2900 ng/g leaf, whereas in clones G7445(1) and G7032(5) it was 180 ng/g leaf and 120 ng/g leaf, respectively. To examine the genetic control of resistance to PLRV multiplication, reciprocal crosses were made between the susceptible cultivar ‘Maris Piper’ and the two resistant clones, and the three parents were selfed. Seedling progenies of these families were grown to generate tubers of individual genotypes (clones). Clonally propagated plants were graft-inoculated, and their daughter tubers were collected and used to grow plants with secondary infection in which PLRV concentration was estimated. The expression of resistance to PLRV multiplication had a bimodal distribution in progenies from crosses between ‘Maris Piper’ and either resistant clone, and also in progeny from selfing the resistant parents, with genotypes segregating into high and low virus titre groups. Only the progeny obtained from selfing ‘Maris Piper’ did not segregate, all genotypes being susceptible to PLRV multiplication. The pattern of segregation obtained from these progenies fits more closely with the genetical hypothesis that resistance to PLRV multiplication is controlled by two unlinked dominant complementary genes, both of which are required for resistance, than with the simpler hypothesis that resistance is conferred by a single dominant gene, as published previously.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01253981
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Molecular-marker-facilitated investigation of host-plant response to Exserohilum turcicum in maize (Zea mays L.): components of resistance (1994)
    Springer
    Theoretical and applied genetics 88 (1994), S. 305-313 
    Details
    ISSN: 1432-2242
    Keywords: Breeding ; Helminthosporium turcicum ; RFLP ; QTLs ; Disease-resistance ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract RFLPs were used to investigate components of host-plant response to Exserohilum turcicum in 150 unselected F2∶3 lines of a B52/Mo17 maize population. Following inoculation with spore suspensions of the pathogen (race 0), components of disease development were measured and then quantitative trait mapping was performed to identify the location and effects of quantitative trait loci (QTLs) determining host-plant response. Components of interest were the average number of lesions per leaf, the average percent leaf tissue diseased (severity) and the average size of lesions (cm2). Based on a LOD threshold of 2.31 (P〈0.05), the number of lesions appears to be associated with QTLs on chromosomes 1S, 3L, 5S. Severity was associated with analogous regions and, in addition, QTLs on chromosomes 7L and 8L. Most QTLs, for either of these two components, involve additive gene action and partial dominance or overdominance. In contrast, lesion size was associated with QTLs on chromosomes 7L and 5L; recessive gene action may be involved at 7L.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223637
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    A linkage map of diploid Avena based on RFLP loci and a locus conferring resistance to nine isolates of Puccinia coronata var. ‘avenae’ (1994)
    Springer
    Theoretical and applied genetics 89 (1994), S. 831-837 
    Details
    ISSN: 1432-2242
    Keywords: Genetics ; Disease resistance ; Monocots
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An F2 oat population was produced by crossing the diploid (n=7) species Avena strigosa (CI 3815) with A. wiestii (CI 1994), resistant and susceptible, respectively, to 40 isolates of Puccinia coronata, the causal agent of crown rust. Eighty-eight F2 individuals were used to construct an RFLP linkage map representing the A genome of cultivated hexaploid oat. Two hundred and eight RFLP loci have been placed into 10 linkage groups. This map covers 2416 cM, with an average of 12 cM between RFLP loci. Eighty-eight F3 lines, derived from F2 individuals used to construct the map, were screened for resistance to 9 isolates of P. coronata. One locus, Pca, was found to confer a dominant resistance phenotype to isolates 203, 258, 263, 264B, 290, 298, 325A, and 345. Pca also conferred resistance to isolate 276; however, an unlinked second gene may also be involved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224505
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Behavioral and life-history components of division of labor in honey bees (Apis mellifera L.) (1994)
    Springer
    Behavioral ecology and sociobiology 34 (1994), S. 117-409 
    Details
    ISSN: 1432-0762
    Keywords: Social insects ; Apis mellifera ; Division of labor ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Variability exists among worker honey bees for components of division of labor. These components are of two types, those that affect foraging behavior and those that affect life-history characteristics of workers. Variable foraging behavior components are: the probability that foraging workers collect (1) pollen only; (2) nectar only; and (3) pollen and nectar on the same trip. Life history components are: (1) the age the workers initiate foraging behavior; (2) the length of the foraging life of a worker; and (3) worker length of life. We show how these components may interact to change the social organization of honey bee colonies and the lifetime foraging productivity of individual workers. Selection acting on foraging behavior components may result in changes in the proportion of workers collecting pollen and nectar. Selection acting on life-history components may affect the size of the foraging population and the distribution of workers between within nest and foraging activities. We suggest that these components define possible sociogenic “pathways” through which colony-level natural selection can change social organization. These pathways may be analogous to developmental pathways in the morphogenesis of individual organisms because small changes in behavioral or life history components of individual workers may lead to major changes in the organizational structure of colonies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00167332
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Reproductive competition in queenless honey bee colonies (Apis mellifera L.) (1994)
    Springer
    Behavioral ecology and sociobiology 35 (1994), S. 99-107 
    Details
    ISSN: 1432-0762
    Keywords: Key words Apis mellifera ; Genetics ; Drone production ; Allozymes ; Reproductive conflict
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previously we reported that there are subfamily differences in drone production in queenless honey bee colonies, but these biases are not always explained by subfamily differences in oviposition behavior. Here we determine whether these puzzling results are best explained by either inadequate sampling of the laying worker population or reproductive conflict among workers resulting in differential treatment of eggs and larvae. Using colonies composed of workers from electrophoretically distinct subfamilies, we collected samples of adult bees engaged in the following behavior: “true” egg laying, “false” egg laying, indeterminate egg laying, egg cannibalism, or nursing (contact with larvae). We also collected samples of drone brood at four different ages: 0 to 2.5-h-old eggs, 0 to 24-h-old eggs, 3 to 8-day-old larvae, and 9 to 14-day-old larvae and pupae. Allozyme analyses revealed significant subfamily differences in the likelihood of exhibiting egg laying, egg cannibalism, and nursing behavior, as well as significant subfamily differences in drone production. There were no subfamily differences among the different types of laying workers collected from each colony, suggesting that discrepancies between subfamily biases in egg-laying behavior and drone production are not due to inadequate sampling of the laying worker population. Subfamily biases in drone brood production within a colony changed significantly with brood age. Laying workers had significantly more developed ovaries than either egg cannibals or nurses, establishing a physiological correlate for the observed behavioral genetic differences. These results suggest there is reproductive conflict among subfamilies and individuals within queenless colonies of honey bees. The implications of these results for the evolution of reproductive conflict, in both queenright and queenless contexts, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002650050075
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Genotypic differences in brood rearing in honey bee colonies: context-specific? (1994)
    Springer
    Behavioral ecology and sociobiology 34 (1994), S. 125-137 
    Details
    ISSN: 1432-0762
    Keywords: Social insects ; Apis mellifera ; Division of labor ; Genetics ; Nepotism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Three experiments were performed to determine whether brood care in honey bee colonies is influenced by colony genetic structure and by social context. In experiment 1, there were significant genotypic biases in the relative likelihood of rearing queens or workers, based on observations of individually labeled workers of known age belonging to two visually distinguishable subfamilies. In experiment 2, no genotypic biases in the relative likelihood of rearing drones or workers was detected, in the same colonies that were used in experiment 1. In experiment 3, there again were significant genotypic differences in the likelihood of rearing queens or workers, based on electrophoretic analyses of workers from a set of colonies with allozyme subfamily markers. There also was an overall significant trend for colonies to show greater subfamily differences in queen rearing when the queens were sisters (half- and super-sisters) rather than unrelated, but these differences were not consistent from trial to trial for some colonies. Results of experiments 1 and 3 demonstrate genotypic differences in queen rearing, which has been reported previously based on more limited behavioral observations. Results from all three experiments suggest that genotypic differences in brood care are influenced by social context and may be more pronounced when workers have a theoretical opportunity to practice nepotism. Finally, we failed to detect persistent interindividual differences in bees from either subfamily in the tendency to rear queen brood, using two different statistical tests. This indicates that the probability of queen rearing was influenced by genotypic differences but not by the effect of prior queen-rearing experience. These results suggest that subfamilies within a colony can specialize on a particular task, such as queen rearing, without individual workers performing that task for extended periods of time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00164183
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Reproductive competition in queenless honey bee colonies (Apis mellifera L.) (1994)
    Springer
    Behavioral ecology and sociobiology 35 (1994), S. 99-107 
    Details
    ISSN: 1432-0762
    Keywords: Apis mellifera ; Genetics ; Drone production ; Allozymes ; Reproductive conflict
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previously we reported that there are subfamily differences in drone production in queenless honey bee colonies, but these biases are not always explained by subfamily differences in oviposition behavior. Here we determine whether these puzzling results are best explained by either inadequate sampling of the laying worker population or reproductive conflict among workers resulting in differential treatment of eggs and larvae. Using colonies composed of workers from electrophoretically distinct subfamilies, we collected samples of adult bees engaged in the following behavior: “true” egg laying, “false” egg laying, indeterminate egg laying, egg cannibalism, or nursing (contact with larvae). We also collected samples of drone brood at four different ages: 0 to 2.5-h-old eggs, 0 to 24-h-old eggs, 3 to 8-day-old larvae, and 9 to 14-day-old larvae and pupae. Allozyme analyses revealed significant subfamily differences in the likelihood of exhibiting egg laying, egg cannibalism, and nursing behavior, as well as significant subfamily differences in drone production. There were no subfamily differences among the different types of laying workers collected from each colony, suggesting that discrepancies between subfamily biases in egg-laying behavior and drone production are not due to inadequate sampling of the laying worker population. Subfamily biases in drone brood production within a colony changed significantly with brood age. Laying workers had significantly more developed ovaries than either egg cannibals or nurses, establishing a physiological correlate for the observed behavioral genetic differences. These results suggest there is reproductive conflict among subfamilies and individuals within queenless colonies of honey bees. The implications of these results for the evolution of reproductive conflict, in both queenright and queenless contexts, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00171499
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    A complex of buckminsterfullerene with sulfur, C60·2S8: synthesis and crystal structure (1994)
    Springer
    Russian chemical bulletin 43 (1994), S. 240-244 
    Details
    ISSN: 1573-9171
    Keywords: C60·2S8 ; fullerene complexes ; synthesis ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The C60·2S8 complex was prepared by reaction of buckminsterfullerene C60 with sulfur in trichloroethylene and its single-crystal X-ray structure was studied at room temperature. Crystals of this compound are monoclinic, space groupC 2/c, a=20.90(1),b=21.10(1),c=10.537(9) Å, β=111.29(7)°,Z=4,d calc=1.89 g·cm−3. The crystal structure of the C60·2S8 complex consists of packed fullerene molecules that form hexagonal channels along thec axis with eight-membered crown-shaped S8 cyclic molecules inside the channels. The distances between the centers of neighboring fullerene molecules are 10.036(7), 10.636(7), and 10.537(9) Å. Each C60 molecule is linked to eight S8 molecules with ten shortened intermolecular contacts C...S 3.41(1)–3.52(2) Å. The average values of the C=C and C-C bond lengths are 1.32(3) and 1.47(3) Å, which attest to a significant degree of localization of electron density in the c60 molecule.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695818
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Genetics of alcoholism: Role of the endogenous opioid system (1994)
    Springer
    Metabolic brain disease 9 (1994), S. 105-131 
    Details
    ISSN: 1573-7365
    Keywords: Alcoholism ; Genetics ; Endorphins ; Enkephalins ; Dynorphins ; Opioid ; Receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract At the present time alcoholism is recognized as a metabolic disease exhibiting the clinical features of craving for alcohol, loss of control over drinking, tolerance and physical dependence on alcohol, while both epidemiological and experimental studies have demonstrated that genetic factors may be important in determining whether an individual has a high or low vulnerability to develop alcoholism. Evidence also indicates that alcoholism is not characterized by a single gene single allele inheritance. Instead it seems that multiple genes and environmental factors interact to increase or decrease an individual's vulnerability to become an alcoholic. Current research is aimed at investigating whether certain behavioral, physiological and biochemical markers are highly associated with the incidence of alcoholism. Among the biochemical markers currently under investigation is the endogenous opioid system and its implication in mediating the reinforcing effects of ethanol. It is the objective of this manuscript to review current research on: (a) the interactions of ethanol with the endogenous opioid system at the molecular level; (b) the existence of genetically determined differences in the response of the endogenous opioid system to ethanol between subjects at high and low risk for excessive ethanol consumption, as well as between lines of animals showing preference or aversion for ethanol solutions; (c) the decrease of alcohol consumption following pretreatment with opioid antagonists; and (d) the possible use of specific opioid receptor antagonists together with behavioral therapy to modify drinking behavior, to control craving and to prevent relapse.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01999765
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Effects of Configuration Around the Chiral Carbon Atoms on the Crystal Properties of Ephedrinium and Pseudoephedrinium Salicylates (1994)
    Springer
    Pharmaceutical research 11 (1994), S. 1549-1556 
    Details
    ISSN: 1573-904X
    Keywords: ephedrine ; pseudoephedrine ; salicylate ; chirality ; salt formation ; homochiral crystal ; racemic compound ; racemic conglomerate ; crystal structure ; conformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The physicochemical properties and crystal structures of the crystalline salts formed by the interaction of an achiral anion, salicylate, with homochiral and racemic ephedrinium and pseudoephedrinium cations were determined. The interaction of ephedrinium or pseudoephedrinium with salicylate in aqueous solution yielded crystalline salts with the notable exception of homochiral ephedrinium. Evaporation of the solvent from solutions of homochiral ephedrine and salicyclic acid in various organic solvents, as well as grinding together solid homochiral ephedrine and solid salicylic acid, yielded viscous semisolids suggesting that homochiral ephedrinium salicylate has a low melting point and/or a high aqueous solubility. Mixing of the two viscous solids, obtained by grinding each of the opposite enantiomers of ephedrine with equimolar salicylic acid, resulted in the formation of racemic ephedrine and subsequently, upon heating, in the formation of racemic ephedrinium salicylate. While racemic ephedrinium salicylate exists as a crystalline compound (P21/n space group) with an equal number of opposite enantiomers in the unit cell, its diastereomer, racemic pseudoephedrinium salicylate, exists as a conglomerate, i.e. a physical mixture, of the homochiral crystals of the opposite enantiomers (each P21 space group). The inability of homochiral ephedrinium to exist as a crystalline salicylate salt at 20–25°C is attributed to its high energy conformation and/or to the poor packing of homochiral ephedrinium salicylate molecules in the crystal lattice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018945401484
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Expression of a reporter gene is reduced by a ribozyme in transgenic plants (1994)
    Springer
    Molecular genetics and genomics 245 (1994), S. 465-470 
    Details
    ISSN: 1617-4623
    Keywords: Gene regulation ; Ribozyme ; npt-gene ; Transgenic tobacco ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A chimeric gene encoding a ribozyme under the control of the cauliflower mosaic virus (CaMV) 35S promoter was introduced into transgenic tobacco plants. In vivo activity of this ribozyme, which was designed to cleave npt mRNA, was previously demonstrated by transient expression assays in plant protoplasts. The ribozyme gene was transferred into transgenic tobacco plants expressing an rbcS-npt chimeric gene as an indicator. Five double transformants out of sixteen exhibited a reduction in the amount of active NPT enzyme. To measure the amount of ribozyme produced, in the absence of its target, the ribozyme and target genes were separated by genetic segregation. The steady-state concentrations of ribozyme and target RNA were shown to be similar in the resulting single transformants. Direct evidence for a correlation between reduced npt gene expression and ribozyme expression was provided by crossing a plant containing only the ribozyme gene with a transgenic plant expressing the npt gene under control of the 35S promoter, i.e. the same promoter used to direct ribozyme expression. The expression of npt was reduced in all progeny containing both transgenes. Both steady-state levels of npt mRNA and amounts of active NPT enzyme are decreased. In addition, our data indicate that, at least in stable transformants, a large excess of ribozyme over target is not a prerequisite for achieving a significant reduction in target gene expression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302259
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    766 cases of oral cleft in Italy (1994)
    Springer
    European journal of epidemiology 10 (1994), S. 317-324 
    Details
    ISSN: 1573-7284
    Keywords: Epidemiology ; Genetics ; Oral clefts ; Registers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Epidemiological and genetic variables for oral clefts were analysed for the years 1981–1989 in a case-control study of congenital malformations in the Emilia Romagna, Veneto, and Friuli regions, and in the Trento and Bolzano hospitals. Birth prevalence for all cases of cleft lip with or without cleft palate (CL(P)) was 8.2 per 10,000 births, and that for cleft palate only (CP) was 6.1 per 10,000. Coexisting abnormalities were found in 23% of CL(P) cases and in 43% of CP. No clusters in time or space were detected. For isolated clefts, a predominance of males among CL(P) and of females among CP was found; epilepsy was the only maternal risk factor correlated with clefts, and an association between clefting and consanguinity was found. Empirical recurrence risks were calculated in both isolated CL(P) and CP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01719356
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Dicyclohexylamides as ionophores for li-selective electrodes. Crystal structures of a triamide ligand and its complex with lithium ion (1994)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 20 (1994), S. 53-71 
    Details
    ISSN: 1573-1111
    Keywords: Lithium ionophores ; podand ; dicyclohexylamides ; Li-complex ; crystal structure ; X-ray analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The influence of structure and lipophilicity of dicyclohexylamides on the lithium selectivity in membrane electrodes is discussed. The crystal structures of the triamide podand1 and its complex with LiBr1b has been determined by X-ray analysis. Crystal data for ligand1: C48H83O6N3, triclinic,P1,a=10.749(2),b=12.097(3),c=19.123(6)Å, α=95.76(2),β=80.06(2), γ=100.27(2)0,V=2403(1) Ã3,Z=2. Crystal data for the lithium complex1b: C48H83O6N3·LiBr·x C2H5OH, monoclinic,P2 1/c,a=21.297(6),b=16.316(8),c=19.450(4) Å,β=110.87(2)0,V=6315(3) Å3,Z=4. In the complex the ligand adopts a conformation in which oxygen binding sites surrounding the Li+ cation form a slightly distorted trigonal prism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00707612
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Cold adaption of enzymes: Structural comparison between salmon and bovine trypsins (1994)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 20 (1994), S. 149-166 
    Details
    ISSN: 0887-3585
    Keywords: crystal structure ; cold adaption ; catalytic efficiency ; protein stability ; anionic ; ectotherm ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The crystal structure of an anionic form of salmon trypsin has been determined at 1.82 Å resolution. We report the first structure of a trypsin from a phoikilothermic organism in a detailed comparison to mammalian trypsins in order to look for structural rationalizations for the cold-adaption features of salmon trypsin. This form of salmon trypsin (T II) comprises 222 residues, and is homologous to bovine trypsin (BT) in about 65% of the primary structure. The tertiary structures are similar, with an overall displacement in main chain atomic positions between salmon trypsin and various crystal structures of bovine trypsin of about 0.8 Å. Intramolecular hydrogen bonds and hydrophobic interactions are compared and discussed in order to estimate possible differences in molecular flexibility which might explain the higher catalytic efficiency and lower thermostability of salmon trypsin compared to bovine trypsin. No overall differences in intramolecular interactions are detected between the two structures, but there are differences in certain regions of the structures which may explain some of the observed differences in physical properties. The distribution of charged residues is different in the two trypsins, and the impact this might have on substrate affinity has been discussed. © 1994 Wiley-Liss, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340200205
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Structure of trichosanthin at 1.88 Å resolution (1994)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 19 (1994), S. 4-13 
    Details
    ISSN: 0887-3585
    Keywords: trichosanthin ; ribosome-inactivating proteins ; crystal structure ; orthorhombic ; molecular replacement ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Trichosanthin (TCS) is one of the single chain ribosome-inactivating proteins (RIPs). The crystals of the orthorhombic form of trichosanthin have been obtained from a citrate buffer (pH 5.4) with KC1 as the precipitant. The crystal belongs to the space group P212121 with a = 38.31, b = 76.22, c = 79.21 Å. The structure was solved by molecular replacement method and refined using the programs XPLOR and PROLSQ to an R-factor of 0.191 for the reflections within the 6-1.88 Å resolution range. The bond length and bond angle in the protein molecule have root-mean-square deviations from ideal value of 0.013 Å and 3.3°, respectively. The refined model includes 247 residues and 197 water molecules. The TCS molecule consists of two structural domains. The large domain contains six α-helices, a six stranded sheet, and an antiparallel β-sheet. The small domain has a largest α-helix, which shows a distinct bend. The possible active site of the molecule located on the cleft between two domains was proposed. In the active site Arg-163 and Glu-160, Glu-189 and Arg-122 form two ion pairs, Glu-189 and Gln-156 are hydrogen bonded to each other. Three water molecules are bonded to the residues in the active site region. The structures of TCS molecule and ricin A-chain (RTA) superimpose quite well, showing that the structures of the two protein molecules are homologous. Comparison of the structures of the TCS molecule in this orthorhombic crystal with that in the monoclinic crystal indicates that there are no essential differences of the structures between the two protein crystals. © 1994 Wiley-Liss, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340190103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Phase and X-ray study of clathrate formation in the tetraisoamylammonium fluoride-water system (1994)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 17 (1994), S. 137-148 
    Details
    ISSN: 1573-1111
    Keywords: Clathrate hydrate ; phase diagram ; crystal structure ; tetraisoamylammonium fluoride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The phase diagram of the binary (i-C5H11)4NF-water system has been studied in the clathrate formation region. Three polyhydrates have been discovered, two of which (1∶38.9 and 1∶32.7) are the known orthorhombic and tetragonal phases:Pbmn,a=11.88,b=21.53,c=12.70 Å,ρ means=1.019 g cm-3 (0°C), m.p.=32.4°C andP42/m, a=23.729,c=12.466 Å,ρ means=1.062 g cm-3, (0°C), m.p.=31.2°C, respectively. A single crystal X-ray analysis of the novel clathrate hydrate (i-C5H11)4NF·27 H2O is reported. This new clathrate hydrate is tetragonal,I4I/a, witha=16.894(5),c=17.111(2) Å,Z=4, (−50°C), and m.p.=34.6°C. Each (i-C5H11)4N+ cation occupies a four-chamber cavity built of 15-hedra 71635942 (idealized description), with small vacant 5444 cavities filling the intervening space.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00711854
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    X-ray structure and thermal analysis of a 1∶1 complex between sulfathiazole andβ-cyclodextrin (1994)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 17 (1994), S. 187-201 
    Details
    ISSN: 1573-1111
    Keywords: β-Cyclodextrin ; sulfathiazole ; inclusion complex ; crystal structure ; thermal analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract An inclusion complex with the formula (β-cyclodextrin) (sulfathiazole) 8.3 H2O has been crystallized and characterized by physicochemical methods including single crystal X-ray analysis. The complex crystallizes in the monoclinic system, space group P21, witha=15.264(4),b= 16.500(6),c=15.559(5) Å,β=117.29(3)o andZ=2. The structure was solved using published co-ordinates forβ-cyclodextrin in an isomorphous complex. Refinement by block-diagonal leastsquares yieldedR=0.061 for 4706 unique observed reflections. Inclusion of sulfathiazole produces a slight ellipticity in the host conformation, but the guest adopts a conformation similar to that observed in its polymorphs. The guest is held in the macrocyclic cavity predominantly by hydrophobic forces, with the phenyl ring near the host primary hydroxyl side and the thiazole ring near the secondary hydroxyl side. The complex packs in layers parallel to theac-plane. Layers are linked by hydrogen bonding to water molecules which are located outside the cyclodextrin cavity. An extensive network of hydrogen bonds mediated chiefly by water molecules stabilizes the crystal structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00711858
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Inclusion complexes of the natural product gossypol. Recognition by gossypol of halogeno methanes. Structure of the dichloromethane complex of gossypol and single crystal conservation after decomposition (1994)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 17 (1994), S. 317-324 
    Details
    ISSN: 1573-1111
    Keywords: Gossypol ; complex ; crystal structure ; single crystal ; desolvation ; polymorph
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The structures of gossypol complexes are extremely sensitive to the halogenomethane present as the guest; e.g. changing the number of Cl atoms in chloromethane derivatives changes the structure of the gossypol complex. The crystals of C30H30O8·CH2Cl2 are monoclinic, space groupC2/c,a=21.320(4),b=19.199(6),c=15.765(2)Å, β=113.05(2)o,V=5916(2)Å3,Z=8,D x=1.35 g/cm3,T=295 K. The structure has been solved by direct methods and refined to the finalR value of 0.084 for 1828 reflections. In the structure H-bonded gossypol molecules form columns, generating channels in the structure which are filled by guest molecules. After decomposition (desolvation) monocrystals of the complexes are conserved without destruction, in which there are rather wide and empty channels though slightly smaller than in the complex. An attempt is made to explain some peculiarities of the behavior of the gossypol polymorph formed on the basis of its structure with empty channels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00707127
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Crystal structure of the product of a condensation reaction of (±)-gossypol with (R)-(+)-1-phenylethylamine. Why do diastereoisomeric diaminogossypols cocrystallize? (1994)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 17 (1994), S. 365-376 
    Details
    ISSN: 1573-1111
    Keywords: Gossypol ; inclusion compounds ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The crystal structure of a compound obtained in a condensation reaction of (±)-gossypol with (R)-(+)-phenylethylamine has been determined by X-ray structure analysis. The crystals of C46H48O6N2·(C4H8O2)2 are monoclinic, space groupP21,a=21.243(3),b=8.666(1),c=28.651(4) Å, β=108.24(1)0,V=5009(3) β3,Z=4,D x=1.195 g cm−3, μ(CuK α)=0.66 mm−1,T=292 K. The structure has been solved by direct methods and refined to the finalR value of 0.091 for 4290 observed reflections and 1049 parameters. There are two diastereoisomeric molecules of the host and four solvent molecules in the asymmetric unit. The host molecules are H-bonded into chains with diastereoisomeric molecules alternating along the chain. The fact that the host prefers the association mode in which molecules with a different configuration of the 2,2′-binaphthyl moiety are H-bonded explains why separation of diastereoisomeric diaminogossypols by fractional crystallization has been unsuccessful. The 1,4-dioxane molecules are accommodated in infinite channels but only every second guest molecule in a channel is H-bonded to the host.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00707132
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    A structural two-ring version of a tubular stack ofβ-rings in crystals of a cyclic D,L-hexapeptide (1994)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 18 (1994), S. 27-36 
    Details
    ISSN: 1573-1111
    Keywords: D,L-hexapeptide ; cyclic ; crystal structure ; stacks ; tubular ; β-rings ; channels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract An X-ray analysis of single crystals (from MeOH) of cyclo(-D-Leu-L-MeLeu-D-Leu-L-MeLeu-D-Leu-L-MeLeu-) has been carried out. The analysis reveals that the molecules of the cyclopeptide occur in the crystals with two slightly different, almost hexagonal backbone conformations of the β-type, and that pairs of molecules with the same conformation interact through their nonmethylated face, forming dimeric units (units A and B) with six interannular H-bonds. This kind of pairing reproduces well that expected for a two-ring element in a stack of antiparalleβ-rings. The X-ray analysis has also revealed the presence in the A units of two water molecules, each at one of two equivalent sites located on the 3-fold axis of the units and equidistant from the center of gravity, and the presence in the B units of one water molecule at the center of the units. This provides experimental support for the idea that stacks ofβ-rings can serve as molecular channels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00706936
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    N(nPr)4[B5O6(OH)4][B(OH)3]2 and N(nBu)4[B5O6(OH)4][B(OH)3]2: Clathrates with a diamondoid arrangement of hydrogen-bonded pentaborate anions (1994)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 18 (1994), S. 161-175 
    Details
    ISSN: 1573-1111
    Keywords: Pentaborate ; boric acid ; clathrate ; diamond-related network ; hydrogen bonding ; tetrapropy-lammonium ; tetrabutylammonium ; crystal structure ; 11B MAS NMR ; 13C MAS NMR ; thermogravimetry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Single-crystal X-ray structure analyses of N(nPr)4[B5O6(OH)4][B(OH)3]2,1, and N(nBu)4 [B5O6(OH)4][B(OH)3]2,2, reveal that these materials are novel clathrates, the isotypic host structures of which are three-dimensional assemblies of hydrogen-bonded [B5O6(OH)4]− ionsand B(OH)3 molecules. The assembly of only the pentaborate anions is a distorted (i.e., along [102] elongated) fourconnected diamond-related network. The N(nPr) 4 + and N(nBu) 4 + ions are trapped within the complex three-dimensional channel systems of the host frameworks. Both1 and2 crystallize monoclinically with space groupP21/c andZ=4. The cell constants are:1:a=13.592(5),b=12.082(2),c=17.355(6) Å, β=106.60(2)° (298K);2:a=13.874(3),b=12.585(1),c=17.588(4) Å, β=107.04(1)° (238 K). The results obtained by both11B and13C MAS NMR spectroscopy are discussed. Thermogravimetric studies under a flowing inert-gas atmosphere suggest that water, stemming from polycondensation of the hydrous borate species, is released from the clathrates at ca. 443 K (1) and 398 K (2) before the decomposition of the organic cations starts at ca. 603 K (1) and 603 K (2).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705819
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    X-ray crystallographic studies of tricarbonylchromium complexes of calix[4]arene conformers: On an unusual conformation which appears in cone conformers (1994)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 19 (1994), S. 227-236 
    Details
    ISSN: 1573-1111
    Keywords: Calixarenes ; arenetricarbonylchromium ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The structures of three arene-tricarbonylchromium complexes prepared from cone and 1,3-alternate-25, 26,27,28-tetrapropoxycalix[4]arene(1) and Cr(CO)6 were determined by single crystal X-ray studies. Crystal data for 1,3-alternate-1·Cr(CO)3 are space groupP21/a,a=19.496(3)Å,b=11.118(2)Å,c=19.121(2)Å, β=109.95°(1) andV=3895Å3. The structure was refined toRw=0.068. Crystal data for cone-1·Cr(CO)3 are space groupP21/a,a=21.457(4)Å,b=12.184(1)Å,c=14.816(2)Å, β=91.61°(1) andV=3872Å3. The structure was refined toRw=0.077. Crystal data for cone-1·2Cr(CO)3 are space groupP21/a,a=18.019(3)Å,b=41.347(4)Å,c=11.743(2)Å, β=97.39°(1) andV=8676Å3. The single crystal included two similar but slightly different structures but the data were successfully refined toRw=0.092. The structure of 1,3-alternate-1·Cr(CO)3 differs only slightly from that of the regular 1,3-alternate calix[4]arene. In contrast, cone-1·Cr(CO)3 and cone-1·2Cr(CO)3 show an unusual conformation with a pair of faced gablelike roofs, which is considerbly distorted from the regular cone calix[4]arene. The origin of this distortion is discussed in combination with the spectral studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00708984
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    12-Membered crown ethers. Lipophilic derivatives of benzo- and naphtho-12-crown-4 and their membrane electrode properties. Crystal structures of benzo-12-crown-4 NaI and KI complexes (1994)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 20 (1994), S. 335-351 
    Details
    ISSN: 1573-1111
    Keywords: 12-Membered crown ethers ; ion-selective membrane electrodes ; complexes ; crystal structure ; X-ray analysis ; conformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Lipophilic derivatives of benzo-12-crown-4 and naphtho-12-crown-4 have been synthesized. The behavior of the parent compounds and their derivatives in membrane ion-selective electrodes have been studied. Selectivity changes have been observed with the rise in lipophilicity. Crystal structures of the NaI and KI complexes of benzo-12-crown-4 (1 and2) have been determined by X-ray analysis. The alkali metal and iodide ions are in direct contact in2 but not in1. Compound1 [Na(benzo-12-crown-4)2]·I is triclinic, witha=13.368(8),b=10.727(7),c=10.325(4) Å; α=73.56(4),β=77.73(4), γ=108.70(5)°;Z=2, space group is $$P\bar 1$$ . Compound2 [K(benzo-12-crown-4)2·I] is monoclinic, witha=15.807(8),b=12.043(4),c=15.601(6) Å,β=117.74(3)°;Z=4, space groupC2/c. In both compounds the cations interact with all oxygen atoms of two crown ether molecules. Correlation of the crystal structures and behavior of the crown ethers in ion-selective membrane electrodes is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00708878
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Synthesis and crystal structure of an organic semiconductor (ET)4[Hg2I6] (1994)
    Springer
    Russian chemical bulletin 43 (1994), S. 1175-1179 
    Details
    ISSN: 1573-9171
    Keywords: organic conductors ; ion-radical salts ; bis(ethylenedithio)tetrathiafulvalene ; mercury iodides ; crystal structure ; electrochemical synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new cation-radical salt (ET)4[Hg2I6] (1), where ET is bis(ethylenedithio)tetrathiafulvalene, has been synthesized in the system ET-HgI3 −-PhCl. An X-ray study of 1 (a=41.02(5),b=23.01(1),c=8.233(2) Å,V=7772(3) Å3, space groupPc21 b,Z=4,d calc=2.308 g cm−3) has established its composition, chemical formula, and the main structural features. The ET cation-radicals are packed in the conducting layer, the type of packing is α″; the [Hg2I6]2− anion has a dimeric structure. The temperature dependence of the conductivity of the (ET)4[Hg2I6] crystals (σ300=6 Ohm−1 cm−1) has a semiconducting character.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00698238
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Synthesis and crystal structure of cyclotris-(4,4′-thiodiphenylene ketone) (1994)
    Springer
    Russian chemical bulletin 43 (1994), S. 1384-1389 
    Details
    ISSN: 1573-9171
    Keywords: synthesis ; macrocyclic thiophenylene ketone ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The side reaction of macrocyclization that occurs during the synthesis of poly-(1,4-phenylenesulfide ketone) by polycondensation of a 4,4-dihalobenzophenone with sodium sulfide was studied. It was found that the major product of this reaction is a cyclic trimer, cyclotris-(4,4"-thiodiphenylene ketone) (1). Despite the fact that ketone bridges are more rigid than sulfide bridges, the yield of the macrocycle is rather high, as it is in the synthesis of poly-(1,4-phenylenesulfide), and reaches 20% under high dilution conditions. The structure of 1 was investigated by X-ray diffraction analysis (R = 0.069 on 3138 reflections). Macrocycle 1 is strongly flattened in the crystal; the conformation observed is determined by the packing, since stereochemical analysis indicates high flexibility of the macrocycle. The solvate acetone molecules incorporated in the crystal are disordered, nevertheless, they are strongly fixed in the cavities and channels of the crystal structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00703700
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Analysis of structure and properties of poly(ethylene terephthalate) fibers (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 2289-2306 
    Details
    ISSN: 0887-6266
    Keywords: poly(ethylene terephthalate) ; fiber ; x-ray diffraction ; crystal structure ; three-phase model ; modulus ; tenecity ; shrinkage ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The structure of four semicrystalline poly(ethylene terephthalate) fibers were analyzed with full-pattern (two-dimensional Rietveld) x-ray diffraction refinement, small-angle x-ray scattering, and thermal mechanical analysis, and compared to some of their known mechanical properties. The classical two-phase model of crystal and amorphous phases were unable to correlate structure and properties. We found that there must be a third phase, an oriented, intermediate phase, located mainly between the fibrils. About 1/3 of the intensity of fiber diffraction of the analyzed samples was contributed from such intermediate phase. For some fiber properties the intermediate phase plays a similar role as proposed for “taut tie molecules.” A simple model for the description of structure-insensitive properties of PET fibers was developed, based on this quantitaitve separation into three phases. The oriented intermediate phase changes the definition and calculation of the basic parameters of the fiber structure, such as crystallinity and orientation. Based on small-angle x-ray evidence, the crystallites are assumed to be separated by layers of largely amorphous material, both surrounded by the intermediate phase. The initial modulus of the fiber is determined mainly by the amount and orientation of the intermediate phase which has a maximum modulus of about 500 g/d on full orientation instead of the earlier predicted 150 g/d for fully oriented semicrystalline fibers. Based on the relationship between tenactity and average orientation function, the maximum tenacity for PET fibers of a structure like the ones analyzed may reach 20-45 g/d instead of earlier predictions of 10 g/d. The additional information needed to understand the structure-sensitive property of shrinkage is discussed. Presently easily accessible parameters have no quantitative predictive capabilities. © 1994 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1994.090321316
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Surface studies of tetraalkylammonium bromides and iodides using atomic force microscopy (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 2653-2659 
    Details
    ISSN: 0887-6266
    Keywords: tetraalkylammonium halide ; atomic force microscopy ; crystal structure ; surface structure ; hextriacontane ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The surface structures of two series of tetra-n-alkylammonium halides, N(CxH2×+1)4I and N(CxH2x+1)4 Br have been investigated with atomic force microscopy (AFM) and compared to hexatriacontane (C36H74). The surfaces could be imaged with atomic resolution. The observed primitive, square surface-patterns of tetra-n-butyl chloride and bromide are in good accord with x-ray single-crystal structure. For n 〉 4, x-ray powder diffraction showed that increasing the alkyl chain-length leads mainly to an appropriate increase of the unit cell along the c-axis, which suggests similar layer structures for all long-chain salts beyond the butyl homologue. Within the centers of the molecular layers of these crystals reside the halide anions and the quaternary nitrogens. The surfaces accessible for AFM consist of methyl end-groups. As the number of carbon atoms increases beyond four, the surface symmetry changes to the face-centered square patterns characteristic of many paraffins. The chains of the tetraalkyl ammonium salts pack, however, less dense than paraffins. © 1994 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1994.090321611
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Liquid crystalline main chain polymers with a poly(p-phenylene-terephthalate) backbone: 7. Thermal expansion of oriented films of the polyester with dodecyloxy side chains (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 851-857 
    Details
    ISSN: 0887-6266
    Keywords: rigid rod polymer ; thermotropic ; aromatic polyester ; oriented film ; thermal expansion ; crystal structure ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The linear thermal expansion coefficients of oriented films of poly(p-phenylene-2,5-didodecyloxy-terephthalate) in the three structures B, A, and Lf are reported. The results are interpreted in terms of a molecular laminate model in which the rigid main-chain layers are separated by the aliphatic side chains. In a film oriented unidirectionally the rigid mainchain layers provide a negative contribution to the thermal expansion coefficient, while the side chains supply a positive contribution. Therefore, the resulting expansion coefficient α depends on the details of the main- and side-chain packing and low-temperature values between α = +0.3 × 10-5 K-1 (A and Lf and α = -1.2 × 10-5 K-1 (B) are found in highly oriented films. Measurements on undrawn films are in accordance with the molecular laminate model. © 1994 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1994.090320508
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Masthead (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 15 (1994) 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020150101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Correlated evolution of the cis-acting regulatory elements and developmental expression of the Drosophila Gld gene in seven species from the subgroup melanogaster (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 15 (1994), S. 38-50 
    Details
    ISSN: 0192-253X
    Keywords: Evolution ; Drosophila ; promoter ; glucose dehydrogenase ; development ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The tissue-specific expression patterns of glucose dehydrogenase (GLD) exhibit a high degree of inter specific variation in the adult reproductive tract among the species in the genus Drosophila. We chose to focus on the evolution of GLD expression and the evolution of the Gld promoter in seven closely related species in the mela-nogaster subgroup as a means of elucidating the relationship of changes in cis-acting regulatory elements in the Gld promoter region with changes in tissue-specific expression. Although little variation in tissue-specific patterns of GLD was found in nonreproductive tissues during development, a surprisingly high level of variation was observed in the expression of GLD in both developing and ma-ture reproductive organs. In some cases this variation is correlated with changes in sequence elements in the Gld promoter which were previously shown to direct tissue-specific expression in the reproductive tract. In particular D. teissieri adult males do not express GLD in their ejaculatory ducts, atypical of the melanogaster subgroup species. The Gld promoter region of D. teissieri specifically lacks all three of the TTAGA regulatory elements present in D. melanogaster. The TTAGA elements were previously shown to direct reporter gene expression to the ejaculatory duct. Together these data suggest the absence or presence of the TTAGA elements may be responsible for variation in the absence or presence of GLD in the ejaculatory duct among species. © 1994 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020150106
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Embryonic expression of the single Tribolium engrailed homolog (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 15 (1994), S. 7-18 
    Details
    ISSN: 0192-253X
    Keywords: Tribolium ; engrailed ; embryogenesis ; segmentation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have cloned and sequenced the single Tribolium homolog of the Drosophila engrailed gene. The predicted protein contains a homeobox and several domains conserved among all engrailed genes identified to date. In addition it contains several features specific to the invected homologs of Bombyx and Drosophila, indicating that these features most likely were present in the ancestral gene in the common ancestor of holometabolous insects. We used the cross-reacting monoclonal antibody, 4D9, to follow the expression of the Engrailed protein during segmentation in Tribolium embryos. As in other insects, Engrailed accumulates in the nuclei of cells along the posterior margin of each segment. The first Engrailed stripe appears as the embryonic rudiment condenses. Then as the rudiment elongates into a germ band, Engrailed stripes appear in an anterior to posterior progression, just prior to morphological evidence of the formation of each segment. As in Drosophila (a long germ insect), expression of engrailed in Tribolium (classified as a short germ insect) is preceeded by the expression of several homologous segmentation genes, suggesting that similar genetic regulatory mechanisms are shared by diverse developmental types. © 1994 Wiley-Liss, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020150103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Screen for enhancers of Polycomb and Polycomblike in Drosophila melanogaster (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 15 (1994), S. 425-434 
    Details
    ISSN: 0192-253X
    Keywords: Polycomb group ; homeotic ; spalt ; devenir ; Su(Pc)37D ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: There are 11 Polycomb group genes known in Drosophila. These genes are negative regulators of homeotic gene expression, and may act by modifying chromatin structure. It is not clear how many members of the Polycomb group of genes exist. Many were discovered because of their homeotic phenotypes, or because they enhance homeotic mutations. Systematic screens for enhancers of Polycomb have identified previously known members of the Polycomb group. In an attempt to discover cytological locations of new Polycomb group genes, we crossed deletions uncovering about 20% of the genome to Polycomb-like and Polycomb and scored for enhancement of the extra sex combs phenotype. Haploidy for four regions, 36F7-37A, 43E18; 44B5-9, 70C2-6, and 70C6-15; 70D enhanced the extra sex comb phenotype associated with strong Polycomb group mutations. These regions have homeotic phenotypes either as homozygous embryos or heterozy-gous adults, or both. We also show that spalt enhances Polycomb group mutations. These results are discussed with respect to previous estimates of Polycomb group gene number. © 1994 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020150505
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Developmental arrest of fertilized eggs from the B6.YDOM sex-reversed female mouse (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 15 (1994), S. 435-442 
    Details
    ISSN: 0192-253X
    Keywords: Fertility ; sex-reversal ; XY ovary ; XY oocyte ; mouse ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: When the Y chromosome of a Mus musculus domesticus mouse strain is placed onto the C57BL/6J (B6) inbred background, the XY progeny develop ovaries or ovotestes but never normal testes during fetal life. While some of the hermaphroditic males become fertile, none of the XY females produces litters. Here, we examined the fertility and development of oocytes derived from the XY female mouse. With or without preceding injection of gonadotropins, female mice were mated with normal B6 males, and their embryos were recovered at various developmental stages. In vitro fertilization was performed with the eggs recovered from the oviduct after treatment with go-nadotropins. Development of embryos was examined by both light and electron microscopy. The results indicate that the oocytes released from the B6.YDOM ovary were efficiently fertilized and often initiated the first cell cleavage, but all embryos died during early preimplantation periods. Even when oocytes were fertilized in vitro, minimizing their exposure to the XY oviduct/uterus environment, most embryos died at the 1- or 2-cell stage. A few exceptional embryos reached the 4- or 8-cell stage, but abnormalities were evident in both nuclear and cytoplasmic structures of all embryos. After cleavage, neighbouring blastomeres were only loosely associated, and microvilli were abundant at the intercellular interfaces. We postulate that oocytes of the B.6.YDOM female mouse become defective during XY ovarian differentiation, and, hence, fail to proceed through normal embryonic development. © 1994 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020150506
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Epigenetic effects in eukaryotic gene expression (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 15 (1994), S. 458-462 
    Details
    ISSN: 0192-253X
    Keywords: Epigenetic phenomena ; chromatin structure ; eukaryotes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In the broadest terms, epigenetic phenomena in eukaryotes depend on the interaction of alleles or repeated sequences or on the mitotic inheritance of chromatin states or methylation patterns. One of the most exciting aspects of the study of epigenetic phenomena is the insight that can be gained into the structure and assembly of higher-order chromatin structures, an important subject that has proved refractory to current biochemical methodologies. Rapid progress in the study of gene inactivation in fungi, plants, and invertebrates will provide new hypotheses to be tested in mammals. © 1994 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020150603
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Positional information and pattern formation in development (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 15 (1994), S. 485-490 
    Details
    ISSN: 0192-253X
    Keywords: Pattern formation ; positional information ; periodic structures ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A widely used mechanism for pattern formation is based on positional information: cells acquire positional identities as in a coordinate system and then interpret this information according to their genetic constitution and developmental history. In Drosophila maternal factors establish the axes and set up a maternal system of positional information on which further patterning is built. There is a cascade of gene activity which leads both to the development of periodic structures, the segments, and to their acquiring a unique identity. This involves the binding of transcription factors to regulatory regions of genes to produce sharp thresholds. Many of the genes involved in these processes, particularly the Hox complex, are also involved in specifying the body axis and limbs of vertebrates. There are striking similarities in the mechanisms for spcifying and recording positional identity in Drosophila and vertebrates. © 1994 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020150607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Experimental embryological analysis of genetic imprinting in mouse development (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 15 (1994), S. 515-522 
    Details
    ISSN: 0192-253X
    Keywords: Genetic imprinting ; androgenesis ; parthenogenesis ; development ; chimeras ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020150610
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Tissue-specific regulation by ecdysone: Distinct patterns of Eip28/29 expression are controlled by different ecdysone response elements (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 15 (1994), S. 320-331 
    Details
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; ecdysone ; steroid ; Eip28/29 ; EcREs ; lacZ ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The Eip28/29 gene of Drosophila is an example of a tissue- and stage-specific ecdysone-responsive gene. Its diverse patterns of expression during the third larval instar and a synopsis of those patterns in terms of expression groups have been reported previously. Here we have studied the expression (in transgenic flies) of reporter genes controlled by Eip28/29-derived flanking DNA. During the middle and late third instar, most tissues exhibit normal expression patterns when controlled by one of two classes of regulatory sequences. Class A sequences include only 657 Np of 5′ flanking DNA from Eip28/29. Class B sequences include an extended 3′ flanking region and a minimal (≤93 Np) 5′ flanking region. The class B sequences include all those elements known to be important for ecdvsone induction in cultured cells. They are sufficient to direct the normal premetamorphic induction of Eip28/29 in the lymph glands, hemocytes, proventriculus, and Malpighian tubules. This is consistent with our suggestion that Kc cells are derived from embryonic hematopoietic cells. It is remarkable that the epidermis requires only class A sequences. These are sufficient to up-regulate expression at medinstar and to down-regulate expression at metamorphosis. It follows that the epidermis uses EcREs distinct from those that function in Kc cells. It is possible that the Upstream EcRE, which is nearly silent in Kc cells, is active in the epidermis. © 1994 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020150403
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Darstellung und Struktur von Tetraethylcyclotetraarsoxan-Komplexen von Kupfer(I)-Halogeniden (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 334-342 
    Details
    ISSN: 0044-2313
    Keywords: Copper(I) halide complexes ; tetraethylcyclotetraarsoxane copper(I) complexes ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Structure of Tetraethylcyclotetraarsoxane Complexes of Copper(I) HalidesThe polymeric complexes [Cu4Cl4{cyclo-(C2H5AsO)4}3]n (1), [Cu3Br3{cyclo-(C2H5AsO)4}2]n (2) and [Cu6I6{cyclo-(C2H5AsO)4}3]n (3) were prepared by the reaction of (C2H5AsO)n and CuX (X = Cl, Br, I) in acetonitrile and characterised by X-ray analysis. All three complexes contain only tetramers (C2H5AsO)4 as ligands, in which the As4O4 ring systems coordinate between two and four Cu-atoms. In each case one As4O4 ring with a crown-shaped conformation is observed, which coordinates either four (in 1) or three (in 2 and 3) axially sited Cu-atoms. In addition there are further (C2H5AsO)4 ligands, which display either a boat-chair- (in 1) or a twist-chair-conformation (in 1-3). The individual building units are connected to one another via Cu—X—Cu bridges (in 2 and 3) and/or centrosymmetric As4O4 ring systems (in 1-3) into chain (1) or layer structures (2 und 3).
    Notes: Die polymeren Komplexe [Cu4Cl4{cyclo-(C2H5AsO)4}3]n (1), [Cu3Br3{cyclo-(C2H5AsO)4}2]n (2) und [Cu6I6{cyclo-(C2H5AsO)4}3]n (3) wurden durch die Umsetzung von (C2H5AsO)n und CuX (X = Cl, Br, I) in Acetonitril dargestellt und durch Röntgenstrukturanalyse charakterisiert. Alle drei Komplexe enthalten lediglich Tetramere (C2H5AsO)4 als Liganden, wobei die As4O4-Ringsysteme zwischen zwei und vier Cu-Atomen koordinieren. Es wird jeweils ein As4O4-Ring mit Kronenkonformation beobachtet, der entweder vier (in 1) oder drei (in 2 und 3) Cu-Atome axial koordiniert. Außerdem liegen weitere (C2H5AsO)4-Liganden in boat-chair- (in 1) oder twist-chair-Konformation (in 1-3) vor. Die einzelnen Baueinheiten werden über Cu—X—Cu-Brücken (in 2 und 3) und/oder zentrosymmetrische As4O4-Ringsysteme (in 1-3) zu Ketten-(1) oder Schichtstrukturen (2 und 3) verknüpft.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200222
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Über die Reaktion von Cp2TiCl2 mit [C(NMe2)3][(CO)4FeC(O)NMe2] - Kristallstruktur von [C(NMe2)3]2[FeCl4] (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 343-345 
    Details
    ISSN: 0044-2313
    Keywords: Hexamethyl guanidinium cation ; tetrachloro iron(II) anion ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Concerning the Reaction of Cp2TiCl2 with [C(NMe2)3][(CO)4FeC(O)NMe2] - Crystal Structure of [C(NMe2)3]2[FeCl4]The title compound forms by the reaction of Cp2TiCl2 with [C(NMe2)3][(CO)4FeC(O)NMe2] in THF solution. It crystallizes in the space group Pbcn with a = 1 566.6(3); b = 976.4(2); c = 1 580.4(4) pm; Z = 4; R = 3.8%. Each [FeCl4]2- in is surrounded by eight cations. Two cations each are connected with one Cl atom by relatively short H … Cl contacts leading to a distortion of the tetrahedral geometry of the anion.
    Notes: Die Titelverbindung entsteht bei der Umsetzung von Cp2TiCl2 mit [C(NMe2)3][(CO)4FeC(O)NMe2] in THF-Lösung. Sie kristallisiert in der Raumgruppe Pbcn mit a = 1 566,6(3); b = 976,4(2); c = 1 580,4(4) pm; Z = 4; R = 3,8%. Jedes [FeCl4]2- Ion ist von acht Kationen umgeben. Je zwei Kationen sind über relativ kurze H … Cl Kontakte mit einem Cl-Atom verbunden, was zu einer Verzerrung der Tetraedergeometrie des Anions führt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200223
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Preparation and x-ray structure of 1,4,2,3,5,6-Dithiatetrazine (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 495-497 
    Details
    ISSN: 0044-2313
    Keywords: Dithiatetrazine ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung und Röntgenstrukturanalyse von 1,4,2,3,5,6-DithiatetrazinDie Umsetzung von Schwefeldichlorid mit sym-EtO2CNHNHCO2Et 1 ergibt S2[N(CO2Et)]4 2, das analytisch, durch NMR und röntgenographisch charakterisiert wird. Die Strukturanalyse von 2 zeigt, daß der S2N4-Ring Sessel-Konformation hat mit allen vier Estergruppen in pseudoaxialen Positionen. Die Bindungslängen und -winkel werden mit denen in 1 und S4(NR)2 verglichen.
    Notes: Reaction of sulfur dichloride with sym-EtO2CNHNHCO2Et 1 gives the title ring system which has been characterised by microanalyses, nmr, and X-Ray crystallography. The X-ray structure of S2[N(CO2Et)]4 2 reveals that the S2N4 ring adopts a chair conformation with all four ester groups in pseudo-axial positions. Bond lengths and angles are compared with 1 and S4(NR)2.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200316
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    o-1λ5,3λ5-Diphosphaphenylen-bis(diphenylphosphan) und seine chelatbildenden Eigenschaften (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 483-488 
    Details
    ISSN: 0044-2313
    Keywords: o-1λ5,3λ5-Diphosphaphenylene-bis(diphenylphosphane) ; nickel(II) chloride chelate complex ; crystal structure ; NMR, Ir spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: o-1λ5,3λ5-Diphosphaphenylene-bis(diphenylphosphane) and its Chelating PropertiesBis(diphenylphosphanyl)acetylene and 1,1′,3,3′-tetrakis(dimethylamino)-1λ5,3λ5-diphosphete react at higher temperatures to yield the title compound 5, which forms easily the chelate complex 6 with nickel(II) chloride.
    Notes: Bis(diphenylphosphanyl)acetylen und 1,1′,3,3′-Tetrakis(dimethylamino)-1λ5,3λ5-diphosphet reagieren bei höheren Temperaturen zur Titelverbindung 5, die mit Nickel(II)-chlorid leicht den Chelatkomplex 6 bildet.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200314
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Pb3Al2F12: Crystal structure of a cyclo-fluoroaluminate related to Ba3Al2F12 (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1449-1454 
    Details
    ISSN: 0044-2313
    Keywords: Lead fluoroaluminate ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pb3Al2F12: Kristallstruktur eines mit zu Ba3Al2F12 verwandten cyclo-FluoroaluminatDas Fluoroaluminat Pb3Al2F12 wurde in Form von Einkristallen durch Hydrothermal-Synthese erhalten und kristallisiert monoklin in P 21/n mit a = 9,435(6) Å, b = 9,610(5) Å, c = 10,100(9) Å, β = 90,59(5)°, V = 915,7(2) Å3, Z = 4, MoKα, λ = 0,71073 Å, R = 0,0463, Rw = 0,0465, 3 044 symmetrieunabhängige gemessene Reflexe. Die Struktur zeigt tetramere, isolierte, von einem Unternetzwerk unabhängiger Fluoridpolyeder eingeschlossene Oktaeder und ist mit Ba3Al2F12 verwandt. Existenz und Struktur der A3M2F12-Verbindungen werden diskutiert.
    Notes: Pb3Al2F12 is a fluorometalate obtained in single-crystal form by hydrothermal synthesis. It crystallizes in the monoclinic system, space group P 21/n, with a = 9.435(6) Å, b = 9.610(5) Å, c = 10.100(9) Å, β = 90.59(5)°, V = 915.7(2) Å3, Z = 4. The structure was solved from single crystal using 3 044 unique reflections (MoKα, λ = 0.71073 Å), R = 0.0463, Rw = 0.0465. The structure exhibits isolated tetrameric groups of octahedra encaged in a subnetwork of independent fluoride polyhedra and is related to that of Ba3Al2F12. A discussion about the existence and the structure of A3M2F12 compounds is given.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200822
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Ein Beitrag über Ba3Pt4HgO11: Das erste Erdkalimetall-Oxoplatinat(II,V)/Oxomercurat (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1471-1475 
    Details
    ISSN: 0044-2313
    Keywords: Barium, mercury, platinum, oxide ; crystal structure ; high pressure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Contribution on Ba3Pt4HgO11: The First Alkaline-Earth Oxoplatinate(II,V)/OxomercurateSingle crystals of Ba3Pt4HgO11 were prepared by oxygen high pressure technique (4 200-3 600 bar) and investigated by X-ray methods. It crystallizes with hexagonal symmetry, space group D3h4—P62c, a = 6.021, c = 17.374 Å, Z = 2. Ba3Pt4HgO11 represents a new structure type, showing structural relationships to Ba2Hg3Pd7O14 and to the precious metal 6L-perovskites. The Hg2+ ions show dumb-bell like coordination, Pt2+ a square-planar surrounding and Pt5+ face shared double octahedra.
    Notes: Ba3Pt4HgO11 wurde unter hohem Sauerstoffdruck (4 200-3 600 bar) einkristallin dargestllt und röntgenographisch untersucht. Die Verbindung kristallisiert hexagonal, Raumgruppe D3h4—P62c mit a = 6,021; c = 17,374 Å; Z = 2. Ba3Pt4HgO11 bildet einen neuen Strukturtyp, der kristallchemische Verwandtschaft zu Ba2Hg3Pd7O14 und den Edelmetall-6L-Perowskiten zeigt. Die Hg2+-Ionen weisen eine hantelförmige, Pt2+ eine quadratisch-planare Koordination auf. Pt5+ bildet mit O2- flächenverknüpfte Doppeloktaeder.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200825
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Die Kristallstruktur von Tris(N,N-diethyl-N′-benzoylselenoureato)cobalt(III) (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1479-1482 
    Details
    ISSN: 0044-2313
    Keywords: Tris(N,N-diethyl-N′-benzoylselenoureato)cobalt(III) ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal Structure of Tris(N,N-diethyl-N′-benzoylselenoureato)cobalt(III)Co(C12H15N2OSe)3 crystallizes in the trigonal space group P3. The cell parameters are a = 16.697(4), c = 8.557(8) Å, Z = 2. The structure was solved with Patterson and direct methods and was refined to a final R-value of 4.59%. CoIII is bidentally coordinated to three N,N-diethyl-N′-benzoylselenourea molecules to form a distorted octahedron with facial arrangement of the selenium and oxygen donor atoms. The Co—Se and Co—O bond lengths are 2.328(2) and 1.943(6) Å, respectively. The arrangement of the molecules within the unit cell leads to the formation of hexagonal channels parallel to the crystallographic c-axis. The wall of the channels is formed by carbon atoms of the phenyl group. The diameter of the channels is 8.148 Å.
    Notes: Co(C12H15N2OSe)3 kristallisiert in der trigonalen Raumgruppe P3 mit den Gitterkonstanten a = 16,697(4), c = 8,557(8) Å, Z = 2. Die Struktur wurde mit Patterson und Direkten Methoden gelöst und bis zu einem R-Wert von 4,59% verfeinert. CoIII bildet mit dem Liganden N,N-Diethyl-N′-benzoylselenoharnstoff einen oktaedrisch koordinierten Neutralkomplex, in dem drei Ligandmoleküle in facialer Anordnung bidental über Selen- und Sauerstoffatome an das Zentralatom gebunden sind. Der Co—Se-Abstand beträgt 2,328(2) Å, der Co—O-Abstand 1,943(6) Å. Die Anordnung der Komplexmoleküle in der Elementarzelle führt zur Ausbildung von hexagonalen Kanälen parallel zur kristallographischen c-Achse. Die Kanalwände werden von Kohlenstoffatomen der Phenylreste gebildet; der Durchmesser der Kanäle beträgt 8,148 Å.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200827
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Hydrate schwacher und starker Basen. XI. Die Kristallstrukturen von NaOH · 3,5H2O und NaOH · 7 H2O. Eine PräzisierungProfessor Horst Sabrowsky zum 60. Geburtstage gewidmet (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1509-1513 
    Details
    ISSN: 0044-2313
    Keywords: Sodium hydroxide hydrates ; crystal structure ; hydrogen bonding ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hydrates of Weak and Strong Bases. XI. The Crystal Structures of NaOH · 3,5H2O and NaOH · 7 H2O. A RefinementThe crystal structures of the hydrates NaOH · 3,5 H2O (space group P21/c, Z = 8 formula units per unit cell; lattice parameters: a = 6.481, b = 12.460, c = 11.681 Å, β = 104.12° at -100°C) and NaOH · 7 H2O (P21/c, Z = 4; a = 7.344, b = 16.356, c = 6.897 Å, β = 92.91° at -150°C) have been redetermined using MoKα diffractometer data. The obtained refinement of the structures, including the localization also of the H atoms for the first time, has led to new findings with respect to the H bonds. In particular, in both hydrates there is one such interaction of the rare type OH- … OH2, from an OH- ion to an H2O molecule, i. e. with the OH- ion as the proton donor.
    Notes: Die Kristallstrukturen der Hydrate NaOH · 3,5H2O (Raumgruppe P21/c, Z = 8 Formeleinheiten pro Elementarzelle; Gitterkonstanten a = 6,481, b = 12,460, c = 11,681 Å, β = 104,12° bei -100°C) und NaOH · 7 H2O (P21/c, Z = 4; a = 7,344, b = 16,356, c = 6,897 Å, β = 92,91° bei -150°C) wurden mit MoKα-Diffraktometerdaten einer Zweitbestimmung unterzogen. Die erreichte Präzisierung der Strukturen, einschließlich der erstmaligen Lokalisierung auch der H-Atome, führte zu neuen Erkenntnissen bezüglich der H-Brücken. Insbesondere gibt es in beiden Hydraten eine solche Wechselwirkung vom seltenen Typ OH- · OH2, von einem OH--Ion zu einem H2O-Molekül, also mit dem OH--Ion als Protondonor.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200903
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Neue Silicate mit „Stuffed Pyrgoms“: CsKNaLi9{Li[SiO4]}4, CsKNa2Li8{Li[SiO4]}4, RbNa3Li8{Li[SiO4]}4 [1] und RbNaLi4{Li[SiO4]}2 [2]Professor Horst Sabrowsky zum 60. Geburtstage gewidmet (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1495-1508 
    Details
    ISSN: 0044-2313
    Keywords: New Lithosilicates ; preparation ; crystal structure ; MAPLE and CHARDI calculations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: More Silicates with „Stuffed Pyrgoms“: CsKNaLi9{Li[SiO4]}4, CsKNa2Li8{Li[SiO4]}4, RbNa3Li8{Li[SiO4]}4 [1] and RbNaLi4{Li[SiO4]}2 [2]Single crystals of the new silicates CsKNaLi9{Li[SiO4]}4, CsKNa2Li8{Li[SiO4]}4, RbNa3Li8{Li[SiO4]}4 and RbNaLi4{Li[SiO4]}2 as well as powder (Rb-containing compounds only) were obtained for the first time. The samples were prepared by heating well ground mixtures of the binary oxides in Ni and Ag tubes, respectively. The structure determination was carried out by four-circle diffractometer data (MoKα radiation; Siemens AED 2):CsKNaLi9{Li[SiO4]}4: tetragonally prismatic crystals, light yellow; 726 I0(hkl), R = 4.4%, Rw = 2.8%; a = 1 102.0(6), c = 637.9(5) pm; Z = 2; space group I4/m; 2 CsO0.55 + Li4TlO4 + glas (560°C, 15 d).CsKNa2Li8{Li[SiO4]}4: tetragonally prismatic crystals, light yellow; 727 I0(hkl), R = 4.4%, Rw = 2.6%; a = 1 103.5(7), c = 637.7(4) pm; Z = 2; space group I4/m; 1.1 CsO0.61 + 1.1 KO0.55 + 1.4 NaO0.52 + 6.5 Li2O + 4 SiO2 (600°C, 60 d).RbNa3Li8{Li[SiO4]}4: tetragonally prismatic crystals, colourless; 600 I0(hkl), R = 2.3%, Rw = 2.0%; a = 1 092.08(6), c = 632.76(4) pm; Z = 2; space group I4/m; 4 RbO0.57 + 3 NaO0.52 + 6.5 Li2O + 4 SiO2 (650°C, 63 d).RbNaLi4{Li[SiO4]}2: monoclinic, ball-shaped, colourless; 1 224 I0(hkl), R = 3.1%, Rw = 3.1%; a = 1 573.10(13), b = 630.48(5), c = 781.25(8) pm, b = 90.566(8)°; Z = 4; space group C2/m; 1.1 RbO0.52 + 1.2 NaO0.45 + 5 Li2O + 4 SiO2 (700°C, 40 d).
    Notes: Einkristalle der neuen Silicate CsKNaLi9{Li[SiO4]}4, CsKNa2Li8{Li[SiO4]}4, RbNa3Li8{Li[SiO4]}4 und RbNaLi4{Li[SiO4]}2, sowie Pulver der Rb-haltigen Verbindungen wurden dargstellt. Die Proben entstanden durch Tempern inniger Gemenge binärer Oxide in geschlossenen Ni- bzw. Ag-Bömbchen. Die Strukturaufklärung erfolgte jeweils durch Vierkreisdiffraktometerdaten (MoKα-Strahlung; Siemens AED 2):CsKNaLi9{Li[SiO4]}4: tetragonale Prismen, hellgelb; 726 I0(hkl), R = 4,4%, Rw = 2,8%; a = 1 102,0(6), c = 637,9(5) pm; Z = 2; Raumgruppe I4/m; 2 CsO0,55 + LiTlO4 + Duran-Glas (560°C, 15 d).CsKNa2Li8{Li[SiO4]}4: tetragonale Prismen, hellgelb; 727 I0(hkl), R = 4,4%, Rw = 2,6%; a = 1 103,5(7), c = 637,7(4) pm; Z = 2; Raumgruppe I4/m; 1,1 CsO0,61 + 1,1 KO0,55 + 1,4 NaO0,52 + 6,5 Li2O + 4 SiO2 (600°C, 60 d).RbNa3Li8{Li[SiO4]}4: tetragonale Prismen, farblos; 600 I0(hkl), R = 2,3%, Rw = 2,0%; a = 1 092,08(6), c = 632,76(4) pm; Z = 2; Raumgruppe I4/m; 4 RbO0,57 + 3 NaO0,52 + 6,5 Li2O + 4 SiO2 (650°C, 63 d).RbNaLi4{Li[SiO4]}2: monoklin, kugelförmig, farblos; 1 224 I0(hkl), R = 3,1%, Rw = 3,1%; a = 1 573,10(13), b = 630,48(5), c = 781,25(8) pm, b = 90,566(8)°; Z = 4; Raumgruppe C2/m; 1,1 RbO0,52 + 1,2 NaO0,45 + 5 Li2O + 4 SiO2 (700°C, 40 d)
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200902
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Cs[Er10(C2)2]I18 und [Er10(C2)2]Br18: zwei neue Beispiele für „reduzierte“ Halogenide der Lanthanide mit isolierten [M10(C2)2]-Clustern (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1532-1536 
    Details
    ISSN: 0044-2313
    Keywords: Erbium Clusters, [Er10(C2)2] ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cs[Er10(C2)2]I18 and [Er10(C2)2]Br18: Two New Examples for Reduced Halides of the Lanthanides with Isolated [M10(C2)2] ClustersCs[Er10(C2)2]I18 is obtained from the reaction of ErI3 with caesium and carbon in sealed tantalum containers at 700°C and [Er10(C2)2]Br18 through the metallothermic reduction of ErBr3 with rubidium in the presence of carbon at 750°C in sealed niobium containers. The crystal structures {Cs[Er10(C2)2]I18: triclinic, P1; a = 1 105.2(8) pm, b = 1 112.0(7) pm; c = 1 122.9(8) pm; α = 66.91(3)°, β = 87.14(3)°; γ = 60.80(3)°; Z = 1; R = 0.049, Rw = 0.043; [Er10(C2)2]Br18: monoclinic, P21/n, a = 971.8(6) pm, b = 1 623.4(9) pm, c = 1 163.8(6) pm, β = 104.00(6)°; Z = 2; R = 0.077, Rw = 0.057} contain isolated dimeric [Er10(C2)2] clusters. Due to the inclusion of C2 units, the octahedra are elongated in the direction of the pseudo C4 axis. The connecting edges of the two octahedra are exceptionally short (316.7 pm and 314.8 pm respectively). The dimeric units are connected via Xi-a and Xa-i (X = Br, I) bridges according to [Er10(C2)2X10iX8/2i-a]X8/2a-i. Cs+ is surrounded by a cuboctahedron of iodide ions in Cs[Er10(C2)2]I18.
    Notes: Cs[Er10(C2)2]I18 entsteht bei der Umsetzung von Erl3 mit Caesium und Kohlenstoff in verschweißten Tantalampullen bei 700°C, [Er10(C2)2]Br18 bei der metallothermischen Reduktion von ErBr3 mit Rubidium in Gegenwart von Kohlenstoff bei 750°C in verschweißten Niobampullen. Die Kristallstrukturen {Cs[Er10(C2)2]I18: triklin, P1; a = 1 105,2(8) pm; b = 1 112,0(7) pm; c = 1 122,9(7) pm; α = 66,91(3)°; β = 87,14(3)°; γ = 60,80(3)°; Z = 1; R = 0,049, Rw = 0,043; [Er10(C2)2]Br18: monoklin, P21/n; a = 971,8(6); b = 1 623,4(9); c = 1 163,8(6); β = 104,00(6)°; Z = 2; R = 0,077, Rw = 0,057} beinhalten isolierte dimere [Er10(C2)2]-Cluster. Wegen des Einbaus der C2-Hantel sind die Oktaeder entlang ihrer pseudovierzähligen Achse gestreckt. Die verknüpfenden Oktaederkanten weisen einen besonders kurzen Metall-Metall-Abstand auf (316,7 bzw. 314,8 pm). Die dimeren Einheiten sind über Xi-a bzw. Xa-i-Brücken (X = Br, I) miteinander verknüpft, gemäß [Er10(C2)2X10iX8/2i-a]X8/2a-i. Cs+ ist in Cs[Er10(C2)2]I18 kuboktaederisch von Iodidionen umgeben.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200907
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Zur Oxydation intermetallischer Phasen: Die Oxoplumbate(II) K6[Pb2O5] [1] und K4[PbO3] [2] (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1549-1558 
    Details
    ISSN: 0044-2313
    Keywords: Potassium plumbates ; preparation ; crystal structure ; MAPLE and CHARDI calculations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Oxidation of Intermetallic Phases: The Oxoplumbates(II) K6[Pb2O5] [1] and K4[PbO3] [2]Very pale yellow crystals of K6[Pb2O5] were obtained by heating a wellground mixture of LiPb und K2O2 (K2O2: LiPb = 2.5:1) in Ag-tubes (550°C; 40 d). The crystal structure, triclinic, space group P1, a = 1 326.7(6); b = 758.8(4); c = 637.0(3) pm; α = 92.17(3)°; β = 94.41(3)°; γ = 112.85(4)°; Z = 2 was determined (four-circle diffractometer data, Mo—Kα-, 3 270 Io(hkl), R = 8.0%, Rw = 3.5%, parameters see text). The pale yellow crystals of K4[PbO3] were received by heating KPb and K2O2 (K2O2: KPb = 3.3:2) in Ni-tubes (450°C; 17 d). The crystal structure (orthorhombic, space group Pbca with a = 658.2(1); b = 1 131.8(4); c = 1 872.2(6) pm; Z = 8) was refined (four-circle diffractometer data, Mo—Kα-, 2 003 Io(hkl), R = 4.9%, Rw = 2.8%).The Madelung Part of Lattice Energy (MAPLE), Effective Coordination Numbers (ECoN), the Mean Fictive Ionic Radii (MEFIR) and the Charge Distribution (CHARDI) are being calculated for both oxides.
    Notes: Äußerst schwach hellgelbe Kristalle von K6[Pb2O5] entstanden beim Tempern inniger Gemenge von LiPb und K2O2 (K2O2: LiPb = 2,5:1) in Ag-Bömbchen (550°C; 40 d). Die Kristallstruktur, triklin, Raumgruppe P1 (I.T. No. 2), mit a = 1 326,7(6); b = 758,8(4); c = 637,0(3) pm; α = 92,17(3)°; β = 94,41(3)°; γ = 112,85(4)°; Z = 2 wurde aufgeklärt (Vierkreisdiffraktometerdaten, Mo—Kα-, 3 270 Io(hkl), R = 8,0%, Rw = 3,5%, Parameter siehe Text). Die blaß gelben Kristalle von K4[PbO3] entstanden beim Tempern von KPb mit K2O2 (K2O2: KPb = 3,3:2) in Ni-Bömbchen (450°C; 17 d). Die Kristallstruktur (orthorhombisch, Raumgruppe Pbca, a = 658,2(1); b = 1131,8(4); c = 1872,2(6) pm; Z = 8) wurde verfeinert (Vierkreisdiffraktometerdaten, Mo—Kα-, 2 003 Io(hkl), R = 4,9%, Rw = 2,8%).Für beide Oxide werden der Madelunganteil der Gitterenergie (MAPLE), Effektive Koordinationszahlen (ECoN), die Mittleren Fiktiven Ionenradien (MEFIR) sowie die Ladungsverteilung (CHARDI) berechnet.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200910
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Ein weiteres Alkali-Erdalkalimetall-Oxoniccolat mit Perowskitstruktur: Sr12NaNi7O23 (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1565-1568 
    Details
    ISSN: 0044-2313
    Keywords: Strontium, sodium, nickel, oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Another Alkaline Alkaline-Earth Oxoniccolate of Perovskite Type Structure: Sr12NaNi7O23Single Crystals of Sr12NaNi7O23 were prepared in closed system by Na2O2 flux reaction. X-ray single crystal work show hexagonal symmetry, space group D32-P321, a = 9.429, c = 7.896 Å, Z = 1. Sr12NaNi7O23 is strongly related to the stackered perovskites containing consequently face shared Ni2O9 double octahedra and Na+ inside a trigonal prismatic coordination by oxygen. One underoccupied oxygen point position decreases the coordination number of one Ni3+ of the Ni2O9 groups and a second surrounded by trigonal prisms to corner connected Ni2O7 double tetrahedra. The crystal chemistry will be discussed with respect to compounds of the same structure.
    Notes: Einkristalle von Sr12NaNi7O23 wurden im geschlossenen System mit Na2O2 als Schmelzmittel dargestellt. Röntgenographische Untersuchungen zeigen hexagonale Symmetrie, Raumgruppe D32-P321; a = 9,429; c = 7,896 Å, Z = 1. Sr12NaNi7O23 ist eng mit den Stapelvarianten der Perowskite verwandt und zeigt flächenverknüpfte Ni2O9-Oktaederdoppel sowie Na+ in einer trigonal prismatischen Koordination von Sauerstoff. Eine unterbesetzte Sauerstofflage erniedrigt die Koordinationszahl von einem Ni3+-Ion in den Ni2O9-Gruppen und von einem weiteren in trigonal prismatischer Koordination. Es entstehen eckenverknüpfte Ni2O7- Doppeltetraeder. Die Kristallchemie wird mit Blick auf Verbindungen vom gleichen Strukturtyp diskutiert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200912
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Ein neues Kupferzinnboratoxid mit isolierten BO3-Baugruppen: Cu5Sn(BO3)2O4 (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1578-1582 
    Details
    ISSN: 0044-2313
    Keywords: Copper, tin, borate, oxide ; synthesis ; crystal structure ; X-ray diffraction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On a New Copper Tin Borate Oxide with Isolated BO3 Units: Cu5Sn(BO3)2O4Single Crystals of the new compound Cu5Sn(BO3)2O4 were obtained by a B2O3 fluxtechnique. They crystallize in a monoclinic distorted variant of a Ludwigite structure with a partly ordered metal distribution. X-ray investigations on single crystals led to the space group C2h5-P21/c (No. 14); a = 6.3526(7); b = 9.502(1); c = 12.100(9) Å; β = 93.30(3)°; Z = 4. All metal-sites are distorted octahedraly coordinated by oxygen-ions. The structure contains BO3-units and oxygen which is not coordinated to boron.
    Notes: Aus einer B2O3-Schmelze gelang die Synthese von Einkristallen der Substanz Cu5Sn(BO3)2O4, die in einer monoklin verzerrten Strukturvariante eines Ludwigites mit weitgehend geordneter Metallverteilung kristallisiert. Röntgenographische Untersuchungen an Einkristallen ergeben die Raumgruppe C2h5-P21/c (Nr. 14); a = 6,3526(7); b = 9,502(1); c = 12,100(9) Å; β = 93,30(3)°; Z = 4. Die Metallkationen sind verzerrt oktaedrisch von Sauerstoffionen koordiniert. Die Struktur weist sowohl isolierte, planare BO3-Baugruppen als auch nicht an Bor gebundenen Sauerstoff auf.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200914
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Synthese und Kristallstrukturen von (PPh4)2[In(S4)(S6)Cl] und (PPh4)2[In(S4)Cl3] (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1607-1612 
    Details
    ISSN: 0044-2313
    Keywords: Indium polysulfido complexes ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structures of (PPh4)2[In(S4)(S6)Cl] and (PPh4)2[In(S4)Cl3]InCl and PPh4Cl yield (PPh4)2[In2Cl6] in acetonitrile. This reacts with Na2S4 in presence of PPh4Cl, forming (PPh4)2[In(S4)(S6)Cl]. Its crystal structure was determined by X-ray diffraction (R = 0.075, 2 282 observed reflexions). It is isotypic with (PPh4)2[In(S4)(S6)Br] and contains anions with trigonal-bipyramidal coordination of In, Cl occupying an axial position, and the S4 and S6 groups being bonded in a chelate manner. The reaction of (PPh4)2[In2Cl6] and sulfur in acetonitrile yielded (PPh4)2[InCl5] and (PPh4)2[In(S4)Cl3]. The crystal structure analysis of the latter (R = 0.072, 4 080 reflexions) revealed an anion with distorted trigonal-bipyramidal coordination of In, the S4 group occupying one axial and one equatorial position; the S4 group shows positional disorder.
    Notes: Aus InCl und PPh4Cl entsteht in Acetonitril (PPh4)2[In2Cl6]. Aus diesem wurde mit Na2S4 im Beisein von PPh4Cl (PPh4)2[In(S4)(S6)Cl] erhalten. Seine Kristallstruktur wurde mittels Röntgenbeugung bestimmt (R = 7,5%, 2 282 beobachtete Reflexe). Es kristallisiert isotyp zum (PPh4)2[In(S4)(S6)Br] und enthält Anionen mit trigonal-bipyramidaler Koordination des In; das Cl-Atom nimmt eine axiale Position ein und die S4- und S6-Gruppe ist jeweils chelatartig gebunden. Aus (PPh4)2[In2Cl6], PPh4Cl und Schwefel entstanden in Acetonitril (PPh4)2[InCl5] und (PPh4)2[In(S4)Cl3]. Nach der Kristallstruktur des letzteren (R = 7,2%, 4 080 Reflexe) ist im [In(S4)Cl3]2--Ion das In-Atom verzerrt trigonal-bipyramidal koordiniert, wobei die S4-Gruppe an eine axiale und eine equatoriale Position gebunden ist; die S4-Gruppe ist fehlgeordnet.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200919
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Verfeinerung der Kristallstruktur von SrO2 (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 879-881 
    Details
    ISSN: 0044-2313
    Keywords: Strontium peroxide ; crystal structure ; composition ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Refinement of the Crystal Structure of SrO2Single crystals of SrO2 have been obtained after high pressure/high temperature reaction of a SrO/KClO3 mixture at 20 kbar, 1 400°C. The crystal structure was refined using 154 unique diffractometer data (I4/mmm; a = 3.5626(3), c = 6.6159(6) Å; Z = 2; R = 0.033, Rw = 0.022, S = 0.932). The O—O distance (1.493(4) Å) is significantly longer than the one previously assumed. From a refinement of the site occupation factor for oxygen a composition SrO1.95(2) has been found for the crystal investigated.
    Notes: Einkristalle von SrO2 wurden durch Hochdruck-Hochtemperatur-Reaktion eines SrO—KClO3-Gemisches bei 20 kbar, 1 400°C erhalten. Die Kristallstruktur wurde auf der Basis von Vierkreisdiffraktometerdaten (154 unabhängige Strukturfaktoren) verfeinert (I4/mmm; a = 3,5626(3), c = 6,6159(6) Å; Z = 2; R = 0,033, Rw = 0,022, S = 0,932). Der gefundene O—O-Abstand ist mit 1,493(4) Å deutlich größer als bisher angenommen. Eine Verfeinerung des Besetzungsfaktors von Sauerstoff ergab für den untersuchten Kristall eine Zusammensetzung SrO1,95(2).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200521
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Darstellung und Kristallstruktur von K6[Al2O6] und Rb6[Al2O6]Professor Heinz Dieter Lutz zum 60. Geburtstage gewidmet (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 882-887 
    Details
    ISSN: 0044-2313
    Keywords: K6[Al2O6], Rb6[Al2O6] ; preparation ; crystal structure ; MAPLE ; CHARDI ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of Crystal Structure of K6[Al2O6] and Rb6[Al2O6]Colourless single crystals of K6[Al2O6] have been prepared from intimate mixtures of KAlO2 and K2O (550°C, 90 d). The structure determination from four-circle diffractometer data (MoKα, 742 Io(hkl), R = 2.2%, Rw = 2.1%) confirms the space group C2/m with Z = 2; a = 698.25 pm, b = 1 103.54 pm, c = 646.49 pm, β = 102.49°.Colourless single crystals of hitherto unknown Rb6[Al2O6] have been prepared from intimate mixtures of RbAlO2 and Rb2O (520°C, 120 d). The structure determination from four-circle diffractometer data (MoKα, 1 240 Io(hkl)) results in the residual values R = 7.2%, Rw = 4.9%; space group C2/m; a = 725.92 pm, b = 1 143.33 pm, c = 678.06 pm, β = 104.05°; Z = 2.K6[Al2O6] and Rb6[Al2O6] are isostructural with K6[Fe2O6]. A characteristic structure unit is the anion [Al2O6]6- consisting of two edge-sharing [AlO4] tetrahedra.Effective Coordination Numbers (ECoN), Mean Fictive Ionic Radii (MEFIR), the Madelung Part of Lattice Energy (MAPLE) and the Charge Distribution (CHARDI) are calculated and discussed.
    Notes: Farblose Einkristalle von K6[Al2O6] wurden aus innigen Gemengen von KAlO2 und K2O erhalten (550°C, 90 d). Die Strukturaufklärung (Vierkreisdiffraktometer, MoKα, 742 Io(hkl), R = 2,2%, Rw = 2,1%) bestätigt die Raumgruppe C2/m mit Z = 2; a = 698,25 pm, b = 1 103,54 pm, c = 646,49 pm, β = 102,49°.Analog erhielten wir erstmals Rb6[Al2O6] aus RbAlO2 und Rb2O in Form farbloser Einkristalle (520°C, 120 d). Die Strukturaufklärung (Vierkreisdiffraktometer, MoKα, 1 240 Io(hkl)) ergab in C2/m die Residualwerte R = 7,2%, Rw = 4,9%; a = 725,92 pm, b = 1 143,33 pm, c = 678,06 pm, β = 104,05°.K6[Al2O6] und Rb6[Al2O6] sind mit K6[Fe2O6] isotyp; charakteristische Strukturelemente sind die Anionen [Al2O6]6-, die aus zwei kantenverknüpften [AlO4]-Tetraedern bestehen.Effektive Koordinationszahlen (ECoN), Mittlere Fiktive Ionenradien (MEFIR), der Madelunganteil der Gitterenergie (MAPLE) sowie die Ladungsverteilung (CHARDI) werden berechnet und diskutiert.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200522
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Die Kristallstruktur von Bis(N,N-diethyl-N′ -benzoylselenoureato)nickel(II)Professor Hans Bock zum 65. Geburtstage gewidmet (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 177-182 
    Details
    ISSN: 0044-2313
    Keywords: Bis(N,N-diethyl-N′-benzoylselenoureato)nickel(II) ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal Structure of Bis(N,N-diethyl-N′ -benzoylselenoureato)nickel(II)Ni(C12H15N2OSe)2 crystallizes in the monoclinic space group P21/c. The cell parameters are a = 11.399(3), b = 16.016(4), c = 14.910(6) Å, β = 104.64(3)° and Z = 4. The structure was solved with Patterson and direct methods and was refined to a final R-value of 5.43%. Nickel is coordinated to two N,N-diethyl-N′ -benzoylselenourea molecules to form a bidentally coordinated chelate complex with cis arrangement of the donor atoms. Coordinaton around the nickel atom is planar while the chelate rings diverge from planarity. The ethyl groups of one diethylamino group are disordered. The Ni—Se bond lengths are 2.244(1) and 2.264(1) Å, the Ni—O bond lengths are 1.871(4) and 1.883(4) Å, respectively.
    Notes: Ni(C12H15N2OSe)2 kristallisiert in der monoklinen Raumgruppe P21/c mit den Gitterkonstanten a = 11,399(3), b = 16,016(4), c = 14,910(6) Å, β = 104,64(3)°, Z = 4. Die Struktur wurde mit Patterson und Direkten Methoden gelöst und bis zu einem R-Wert von 5,43% verfeinert. Nickel bildet mit dem Liganden N,N-Diethyl-N′-benzoylselenoharnstoff einen bidental koordinierten Chelatkomplex, in dem zwei Ligandmoleküle über Selen- und Sauerstoffatome in cis-Anordnung an das Zentralatom koordiniert sind. Die Koordinationssphäre um das Nickelatom ist planar, die Chelatringe weichen dagegen deutlich von der Planarität ab. Die Ethylgruppen einer Diethylaminogruppe sind fehlgeordnet. Die Ni—Se-Abstände betragen 2,244(1) und 2,264(1) Å, die Ni—O-Abstände 1,871(4) und 1,883(4) Å.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200129
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    CdHgO2: Ein Oxomercurat mit Verwandtschaft zur Crednerit-StrukturProfessor Wilhelm Preetz zum 60. Geburtstage gewidmet (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1137-1141 
    Details
    ISSN: 0044-2313
    Keywords: Cadmium ; mercury ; oxide ; high pressure ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: CdHgO2: An Oxomercurate related to the Crednerite StructureSingle crystals of CdHgO2 were prepared by oxygen high pressure technique (600°C, 3900 bar) and investigated by X-ray technique. It crystallizes with monoclinic symmetry, space group C2h3-C2/m; a = 5.933, b = 3.452, c = 5.875 Å, β = 91.26°; Z = 2. The Hg2+ ions show dumb-bell like coordination, Cd2+ an octahedral one. CdHgO2 shows strong relationship to the Crednerite structure. The orientation of the O—Hg—O dump-bells to the CdO6 octahedra layers is discussed with respect to related oxomercurates.
    Notes: CdHgO2 wurde mit Sauerstoff-Hochdrucktechnik (600°C, 3900 bar) einkristallin dargestellt und röntgenographisch untersucht. Es kristallisiert monoklin, Raumgruppe C2h3-C2/m mit a = 5,933, b = 3,452, c = 5,875 Å, β = 91,26° und Z = 2. Die Hg2+-Ionen zeigen eine hantelförmige, Cd2+ eine oktaedrische Koordination. CdHgO2 zeigt große Ähnlichkeit zur Crednerit-Struktur. Die Anordnung der O—Hg—O-Hanteln zu den CdO6-Oktaederschichten wird unter Bezug auf verwandte Oxomercurate diskutiert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200702
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Cu3SbS3: Zur Kristallstruktur und PolymorphieProfessor Heinz Dieter Lutz zum 60. Geburtstag gewidmet (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1992-1997 
    Details
    ISSN: 0044-2313
    Keywords: Copper antimony sulfide ; sulfo salts ; crystal structure ; phase transitions ; Extended Hückel calculations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cu3SbS3: Crystal Structure and PolymorphismThe hitherto unknown crystal structure of β-Cu3SbS3 at room temperature could be determined from a twinned crystal. The compound crystallizes in the monoclinic system, space group P21/c (No. 14), with a = 7.808(1), b = 10.233(2) and c = 13.268(2) Å, β = 90.31(1)°, V = 1 060.1(2) Å3, Z = 8. An Extended-Hückel-Calculation shows weak bonding interactions between copper atoms which are coordinated trigonal planar. At -9°C a first order phase transition occurs and the crystals disintegrate. The low-temperature modification (γ) crystallizes in the orthorhombic system with a = 7.884(2), b = 10.219(2) and c = 6.623(2) Å, V = 533.6(2) Å3 (-100°C). At 121°C a phase transition of higher order is observed. The high-temperature polymorph (α) of Cu3SbS3 is orthorhombic again. From high-temperature precession photographs the space groups Pnma (No. 62) or Pna21 (No. 33) can be derived. The lattice constants at 200°C are a = 7.828(3), b = 10.276(4) and c = 6.604(3) Å, V = 531.2(2) Å3.
    Notes: Die bisher unbekannte Kristallstruktur von β-Cu3SbS3 bei Zimmertemperatur wurde anhand eines verzwillingten Kristalls ermittelt. Die Verbindung kristallisiert monoklin, RG P21/c (Nr. 14) mit a = 7,808(1), b = 10,233(2) und c = 13,268(2) Å, β = 90,31(1)°, V = 1 060,1(2) Å3, Z = 8. Eine Extended-Hückel-Rechnung ergibt schwach bindende Wechselwirkungen zwischen den trigonal-planar koordinierten Kupferatomen. Bei -9°C erfolgt eine reversible Phasenumwandlung 1. Ordnung, bei der die Kristalle zerfallen. Die Tieftemperaturmodifikation (γ) kristallisiert orthorhombisch mit a = 7,884(2), b = 10,219(2) und c = 6,623(2) Å, V = 533,6(2) Å3 (-100°C). Beim Aufheizen beobachtet man bei 121°C eine Phasenumwandlung höherer Ordnung. Die Hochtemperaturmodifikation (α) von Cu3SbS3 kristallisiert ebenfalls orthorhombisch. Aus Hochtemperatur-Präzessionsaufnahmen ergibt sich Pnma (Nr. 62) oder Pna21 (Nr. 33) als mögliche Raumgruppe. Die Gitterkonstanten bei 200°C sind nach Guinier-Aufnahmen a = 7,828(3), b = 10,276(4) und c = 6,604(3) Å, V = 531,2(2) Å3.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946201126
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Li10Si2PbIIO10 = Li20[(SiO4)4(OPbO2PbO)]  -  Das erste „gemischte“ Silicat-Plumbat(II)Professor Kurt Issleib in memoriam (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 2026-2032 
    Details
    ISSN: 0044-2313
    Keywords: Lithium silicate plumbate ; preparation ; crystal structure ; MAPLE and CHARDI calculations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Li10Si2PbIIO10 = Li20[(SiO4)4(OPbO2PbO)]  -  The first „mixed“ Silicate-Plumbate(II)Colourless crystals of Li10Si2PbO10 were obtained by heating a well-ground mixture of LiPb, Li2O2 and „SiO2“ (deriving from Duran glas) in Ag-tubes (650°C; 60 d). The crystal structure was determined (four-circle diffractometer data, Mo—Kα-, 1 474 Io(hkl), R = 4.2%, Rw = 2.8%, parameters see text). The silicate-plumbate crystallizes monoclinic (space group C2/m; I. T. No. 12) with a = 2985.1(4); b = 610.6(6); c = 512.8(1) pm, β = 99.70(9)° (four-circle data), Z = 4.Further the Madelung Part of Lattice Energy (MAPLE), Effective Coordination Numbers (ECoN), the Mean Fictive Ionic Radii (MEFIR) and the Charge Distribution (CHARDI) are being calculated.
    Notes: Farblose Kristalle von Li10Si2PbO10 entstanden beim Tempern inniger Gemenge von LiPb, Li2O2 und „SiO2“ (aus Duranglas) in Ag-Bömbchen (650°C; 60 d). Die Kristallstruktur wurde aufgeklärt (Vierkreisdiffraktometerdaten, Mo—Kα-, 1 474 Io(hkl), R = 4,2%, Rw = 2,8%, Parameter siehe Text). Das Silicat-Plumbat kristallisiert monoklin (Raumgruppe C2/m; I. T. No. 12) mit a = 2 985,1(4); b = 610,6(1); c = 512,8(1) pm; β = 99,70(9) (Vierkreisdaten), Z = 4.Ferner werden der Madelunganteil der Gitterenergie (MAPLE), Effektive Koordinationszahlen (ECoN), die Mittleren Fiktiven Ionenradien (MEFIR) sowie die Ladungsverteilung (CHARDI) berechnet.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946201203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Neue Rheniumkomplexe mit Trichalkogenido- und Tetrachalkogenido-Chelatliganden (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 299-303 
    Details
    ISSN: 0044-2313
    Keywords: Rhenium complexes ; rhenium trichalcogenido, -tetrachalcogenido complexes ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Rhenium Complexes Containing Trichalcogenido and Tetrachalcogenido Chelate LigandsThe reactions of Cp*ReCl4 with polychalcogenide salts such as Na2S4 or (NEt4)2Se6 lead initially to the violet trichalcogenido chelate complexes Cp*ReCl2(E3) (E = S (3a), Se (3b)) which, due to their functional chloro ligands, can be used as intermediates for further reactions. Upon hydrolysis in moist solvents or aminolysis with tert. butylamine 3a, b are converted into the tetrachalcogenido chelate complexes Cp*Re(O)(E4) (E = S (4a), Se (4b)) and Cp*Re(NtBu)(E4) (E = S (5a), Se (5b)), respectively. X-Ray structure analyses were carried out for the three mononuclear cyclo-oligoselenido compounds 3b-5b. It appears that the size of the Se2-n chelate ring (n = 3 or 4) essentially depends on steric factors within the coordination sphere of rhenium.
    Notes: Die Reaktionen von Cp*ReCl4 mit Polychalkogenid-Salzen wie Na2S4 oder (NEt4)2Se6 führen zunächst zu den violetten Trichalkogenido-Chelatkomplexen Cp*ReCl2(E3) (E = S (3a), Se (3a), die aufgrund der funktionellen Chloroliganden als Zwischenstufen bei weiteren Reaktionen verwendet werden können. Bei Hydrolyse in feuchten Solvenzien oder Aminolyse mit tert. Butylamin werden 3a, b in die Tetrachalkogenido-Chelatkomplexe Cp*Re(O)(E4) (E = S (4a), Se (4b) bzw. Cp*Re(NtBu)(E4) (E = S (5a), Se (5b) umgewandelt. Für die drei einkernigen cyclo-Oligoselenido-Verbindungen 3b-5b wurden Röntgenstrukturanalysen durchgeführt. Es scheint, daß die Größe des Se2-n-Chelatrings (n = 3 oder 4) im wesentlichen von sterischen Faktoren innerhalb der Koordinationssphäre des Rheniums abhängt.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200214
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Crystal Structure of a New Acentric Oxide Fluoride of VIV: BaVOF4 (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 309-312 
    Details
    ISSN: 0044-2313
    Keywords: Barium vanadium oxide fluoride ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Kristallstruktur eines neuen azentrischen Oxidfluorids des VIV: BaVOF4Die Struktur von BaVOF4, erhalten durch hydrothermale Synthese, wurde röntgendiffraktometrisch aus Einkristalldaten bestimmt: Raumgruppe Fdd2 (azentrisch), Z = 16, a = 7,920(1), b = 27,608(2), c = 7,375(1) Å mit R = 0,0262, Rw = 0,0273 für 1 508 unabhängige Reflexe und 64 Parameter. Das Gitter wird von cis-verknüpften VOF5-Oktaedern aus gewinkelten unendlichen Ketten entlang [101] und [101] gebildet, die über Barium-Kationen verbunden sind. Die Lage der O2- und F- wird mittels Valenzband-Rechnungen diskutiert. Wie für BaTiOF4 und einige Verbindungen aus der Reihe AIIMIIIF5 (A = Ba, Sr und M = Ga, Al, Mn) kann die Struktur durch quasi-hexagonal dichteste Ebenen aus Stapeln von Ba2+, O2-- und F--Ionen beschrieben werden.
    Notes: The structure of BaVOF4 has been determined by X-ray diffraction data from a single crystal obtained by hydrothermal synthesis: S.G. Fdd2 (acentric), Z = 16, a = 7.920(1), b = 27.608(2) and c = 7.375(1) Å with R = 0.0262 and Rw = 0.0273 for 1 508 independent reflections and 64 parameters. The network is built up from cis-linked VOF5 octahedra forming infinite kinked chains running along the [101] and [101] directions, connected by barium cations. The location of O2- and F- ions is discussed using bond valence calculations. As for BaTiOF4 and some compounds in the series AIIMIIIF5 (A = Ba, Sr and M = Ga, Al, Mn), the structure can be described in terms of a quasi hexagonal compact planes stacking of Ba2+, O2- and F- ions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200216
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Synthese und Kristallstruktur von Ba25Cu142+Cu43+Zn4O49 (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 313-318 
    Details
    ISSN: 0044-2313
    Keywords: Barium, copper, zinc, oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of Ba25Cu142+Cu43+Zn4O49Single crystals of Ba25Cu142+Cu43+Zn4O49 were prepared with solid state and flux reactions. X-ray investigations show tetragonal symmetry, space group D74th-P4/nmm, a = 18.2146, c = 9.3230 Å, Z = 2. The hitherto unknown structure type shows copper in square pyramids and planar polygones, connected to six member rings or Cu5O20 groups. Slightly bent Cu5O12 groups produced by edge connection of five CuO4 polygones are connected with ZnO4 tetrahedra forming Cu5Zn4O20 units. The complicated structure is shown step by step.
    Notes: Einkristalle von Ba25Cu142+Cu43+Zn4O49 wurden mit einer Kombination von Feststoff- und Schmelzmittel-reaktionen dargestellt. Diese Substanz kristallisiert tetragonal, Raumgruppe D74th-P4/nmm mit a = 18,2146, c = 9,3230 Å, Z = 2. Der bisher unbekannte Strukturtyp zeigt Kupfer in tetragonal pyramidaler und planarer Koordination. Diese Polygone sind zu Sechsringen oder Cu5O20-Baugruppen verknüpft. Schwach gebogene Cu5O12-Baugruppen, die durch Kantenverknüpfung von fünf planaren CuO4-Polygonen gebildet werden, sind mit ZnO4-Tetraedern verknüpft und bilden Cu5Zn4O20-Baueinheiten aus. Die komplizierte Kristallstruktur wird schrittweise aufgebaut.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200217
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Ein Beitrag über ein cobaltreiches Oxoarsenat/-vanadat: Co5AsVO10 (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 319-322 
    Details
    ISSN: 0044-2313
    Keywords: Cobalt, arsenic, nickel, oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Contribution about a New Cobalt-rich Oxoarsenate/-vanadate: Co5AsVO10Single crystals of Co5AsVO10 were prepared by solid state reactions and investigated by X-ray structure determination. It crystallizes with monoclinic symmetry, space group C2h3-C2/m, a = 19.134, b = 6.095, c = 17.482 Å, β = 133.37°; Z = 8. The new structure type is characterized by layers of CoO6- and AsO6-octahedra with partly alternating occupation. The layers are connected by Co2+ within tetrahedral oxygen coordination and tetrahedra around statistically occupied point positions of V5+ /As5+.
    Notes: Einkristalle von Co5AsVO10 wurden durch Feststoffreaktionen erhalten und röntgenographisch untersucht. Diese Verbindung kristallisiert mit monokliner Symmetrie, Raumgruppe C2h3-C2/m; a = 19,134; b = 6,095; c = 17,482 Å; β = 133,37°; Z = 8. Der neue Strukturtyp ist durch CoO6- und AsO6-Oktaederschichten ausgezeichnet, die teilweise alternierend mit Co2+ und As5+ besetzt sind. Die Oktaederschichten werden durch Co2+ in tetraedrischer Koordination und statistisch mit V5+ und As5+ besetzte Punktlagen verknüpft.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200218
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    On the Crystal Structure of LaCaCuGaO5 (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 326-328 
    Details
    ISSN: 0044-2313
    Keywords: Lanthanum calcium copper gallate ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zur Kristallstruktur von LaCaCuGaO5Die Kristallstruktur von LaCaCuGaO5 wurde röntgenographisch an Einkristallen untersucht. Es kristallisiert orthorhombisch in der Raumgruppe C2v22-Ima2 mit a = 15,8467, b = 5,5077, c = 5,3188 Å, Z = 4. LaCaCuGaO5 gehört zum Brownmillerit-Typ und zeigt somit Schichten von eckenverknüpften CuO6-Oktaedern, die über GaO4-Tetraeder vernetzt sind. Die La3+- bzw. Ca2+-Ionen besetzen eine Punktlage statistisch.
    Notes: The crystal structure of LaCaCuGaO5 has been investigated by single crystal X-ray analysis. It crystallizes with orthorhombic symmetry, space group C2v22-Ima2, a = 15.8467, b = 5,5077, c = 5.3188 Å, Z = 4. LaCaCuGaO5 belongs to the mineral Brownmillerite showing layers of corner connected CuO6 octahedra linked by GaO4 tetrahedra. The La3+ and Ca2+ ions are distributed statistically over one crystallographic point position.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200220
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Einkristall-Röntgenstrukturanalyse von Sr3TiGa10O20 (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 323-325 
    Details
    ISSN: 0044-2313
    Keywords: Strontium, titanium, gallium, oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Single Crystal X-Ray Analysis of Sr3TiGa10O20Single crystals of Sr3TiGa10O20 were prepared by recrystallisation of a molten oxide mixture and investigated by X-Ray technique. It crystallizes with monoclinic symmetry, space group C2h3-C2/m, a = 15.451, b = 11.579, c = 5.051 Å, β = 108.57°, Z = 2. Sr3TiGa10O20 belongs to the Pb3GeAl10O20 type, showing Ga3+ in tetrahedral and octahedral coordination. The octahedral coordinated point positions are occupied by Ga3+ and Ti4+ statistically.
    Notes: Einkristalle von Sr3TiGa10O20 wurden durch Rekristallisation aus Schmelzen erhalten und röntgenographisch untersucht. Diese Verbindung kristallisiert mit monokliner Symmetrie, Raumgruppe C2h3-C2/m, a = 15,451; b = 11,579; c = 5,051 Å; β = 108,57°; Z = 2. Sr3TiGa10O20 gehört zum Pb3GeAl10O20-Typ und zeigt Ga3+ in tetraedrischer und oktaedrischer Koordination. Die oktaedrisch koordinierten Punktlagen sind mit Ga3+ und Ti4+ statistisch besetzt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200219
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Zur Existenz des Tetrahydrogenorthoperiodations Die Kristallstruktur von LiH4IO6 · H2O (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 805-808 
    Details
    ISSN: 0044-2313
    Keywords: Lithiumtetrahydrogenorthoperiodate monohydrate ; crystal structure ; tetrahydrogenorthoperiodate Ion ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Existence of the Tetrahydrogenorthoperiodate Ion. The Crystal Structure of LiH4IO6 · H2OThe crystal structure of LiH4IO6 · H2O has been determined (P1; a = 564.74(12), b = 574.41(13), c = 970.4(6) pm, α = 101.37(2), β = 96.37(2), γ = 114.72(2)°; Z = 2; 5 731 independent reflections; R = 0.038). All hydrogen-atoms were localized from difference fourier map and refined without applying constraints. Thus the existence of the tetrahydrogenorthoperiodate-ion in the solid state is proved, unambigously. The crystal structure is discussed and compared to other alkaliorthoperiodates.
    Notes: Die Kristallstruktur von LiH4IO6 · H2O wurde bestimmt (P1; a = 564,74(12), b = 574,41(13), c = 970,4(6) pm, α = 101,37(2), β = 96,37(2), γ = 114,72(2)°; Z = 2; 5 731 unabhängige Reflexe, R = 0,038). Alle Wasserstofflagen konnten aufgefunden und frei verfeinert werden und beweisen erstmals die Existenz des Tetrahydrogenorthoperiodations im Festkörper. Die Kristallstruktur wird diskutiert und mit denjenigen anderer Alkaliorthoperiodate verglichen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200508
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Synthesis of cis-Tetrabromobispyridinemolybdates(III) and the crystal structure of cis-(NH4)[MoBr4py2] · ⅓3 H2O (py = pyridine) (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 950-954 
    Details
    ISSN: 0044-2313
    Keywords: Tetrabromobispyridinemolybdates ; preparation ; isomerisation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung von cis-tetrabromobispyridinemolybdaten(III) und die Kristallstruktur von cis-(NH4)[MoBr4py2] · ⅓ H2O (py = Pyridin)(NH4)2[MoBr5 · H2O] reagiert mit Pyridin im Acetonitril (CH3CN) bei Zimmertemperatur. Das Produkt ist ein Gemenge von cis- und trans-(pyH)[MoBr4py2], das auf Grund der Löslichkeitsunterschiede aufgetrennt werden kann. cis-M[MoBr4py2] · ⅓ H2O (M = NH4+, Rb+, Cs+), cis-(bipyH)[MoBr4py2] (bipy = 2,2′-Bipyridyl) und cis-(PPh4)[MoBr4py2] wurden aus cis-(pyH)[MoBr4py2] dargestellt.In siedendem Acetonitril (82°C) erfolgt irreversible cis-trans-Isomerisierung. Brom oxidiert das cis-Diastereoisomere zu trans-MoBr4py2.Die Verbindungen wurden durch chemische Analyse, Infrarot-, UV-VIS-Spektroskopie, Konduktometrie und Röntgen-Pulveraufnahmen charakterisiert.Die Kristallstruktur von cis-(NH4)[MoBr4py2] · ⅓ H2O wurde bestimmt: rhomboedrisch, R3c, (No. 161), a = 15,809(3) Å, β = 112,79(2)°, Z = 6, Dröntg. = 2,29, Dgemess. = 2,27(3) g/cm3, V = 2 601(1) Å3, R1 = 0,046, Rw = 0,068. Die mittleren Mo—Br und Mo—N(Pyridin)-Abstände sind 2,58(2) bzw. 2,20(2) Å. cis-Rb[MoBr4py2] · ⅓ H2O und cis-Cs[MoBr4py2] · ⅓ H2O sind isostrukturell mit cis-(NH4)[MoBr4py2] · ⅓ H2O.
    Notes: The reaction between (NH4)[MoBr5 · H2O] and pyridine in acetonitrile (CH3CN) at room temperature results in the mixture of cis- and trans-(pyH)[MoBr4py2] which can be separated on the basis of solubility. cis-M[MoBr4py2] · ⅓ H2O (M = NH4+, Rb+, Cs+), cis-(bipyH)[MoBr4py2] (bipy = 2,2′-bipyridil) and cis-(PPh4)[MoBr4py2], were prepared from cis-(pyH)[MoBr4py2].At the temperature of boiling acetonitrile irreversible cis to trans isomerisation takes place. Bromine oxydizes cis isomers at room temperature to trans-MoBr4py2.The compounds were characterised by chemical analysis, infrared, UV-VIS spectroscopy, conductivity measurements and powder diffraction.The crystal structure of cis-(NH4)[MoBr4py2] · ⅓ H2O has been determined: rhombohedral, R3c, (No. 161), a = 15.809(3) Å, β = 112.79(2)°, Z = 6, DC = 2.29, DO = 2.27(3) g/cm3, V = 2 601(1) Å3, R1 = 0.046, Rw = 0.068. Average Mo—Br and Mo—N(pyridine) distances within the anion are 2.58(2) and 2.20(2) Å. cis-Rb[MoBr4py2] · ⅓ H2O and cis-Cs[MoBr4py2] · ⅓ H2O are isostructural with cis-(NH4)[MoBr4py2] · ⅓ H2O.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200534
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Synthesis, crystal structure, magnetism, and absorption spectra of A2UX5 Type Halides (A = K, Rb; X = Cl, Br, I)Dedicated to Professor Hugo F. Franzen on his 60th Birthday (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1339-1345 
    Details
    ISSN: 0044-2313
    Keywords: Alkali uranium halides, A2UX5 (A = K, Rb; X = Cl, Br, I) ; preparation ; crystal structure ; magnetic susceptibility ; UV-Vis spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese, Kristallstruktur, Magnetismus und Absorptionsspektren von Halogeniden des Typs A2UX5 (A = K, Rb; X = Cl, Br, I)Die ternären Uran(III)-halogenide A2UX5 (A = K, Rb; X = Cl, Br, I) wurden aus den binären Komponenten AX und UX3 in verschweißten Tantalampullen gewonnen. Nach Guinier-Aufnahmen (Raumtemperatur) kristallisieren sie sämtlich im K2PrCl5/Y2HfS5-Typ. Einkristall-Strukturverfeinerungen wurden für K2UI5 und Rb2UCl5 unternommen. Magnetische Suszeptibilitätsmessungen erfolgten mit einem SQUID-Magnetometer von Raumtemperatur bis zur Temperatur des flüssigen Heliums: Eindimensionale (innerhalb einer Kette) und dreidimensionale antiferromagnetische Ordnung wird bei tiefen Temperaturen, abhängig vom Abstand U3+—U3+, beobachtet. Absorptionsspektren wurden zwischen 4000 und 28000 cm-1 aufgenommen. Sie zeigen die für U3+ charakteristischen Übergänge und, abhängig vom Halogenid, sehr starke f - d Übergänge oberhalb 14000 bzw. 15000 cm-1.
    Notes: The ternary uranium(III) halides A2UX5 (A = K, Rb; X = Cl, Br, I) have been prepared from the binary components AX and UX3 in sealed tantalum containers. According to their Guinier X-ray powder patterns, they all crystallize with the K2PrCl5/Y2HfS5 type of structure. Lattice constants for ambient temperature are reported. Single-crystal structure refinemens were undertaken for K2UI5 and Rb2UCl5. Magnetic susceptibility data were recorded with a SQUID magnetometer from liquid helium to room temperature. One-dimensional (intrachain) and three-dimensional antiferromagnetic ordering occur at low temperatures dependent upon the U3+—U3+ distance. Absorption spectra were recorded between 4 000 and 28 000 cm-1. They show f - f transitions typical for U3+ and, depending on the halide, very strong f - d transitions above 14 000 to 15 000 cm-1, respectively.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200802
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...