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  • 1990-1994  (445)
  • 1994  (445)
  • Genetics  (291)
  • crystal structure  (154)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Sexual plant reproduction 7 (1994), S. 290-296 
    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.
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  • 2
    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.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 89 (1994), S. 959-963 
    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.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric cardiology 15 (1994), S. 198-200 
    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.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric cardiology 15 (1994), S. 201-203 
    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.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 72 (1994), S. 409-413 
    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.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 50 (1994), S. 429-437 
    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
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  • 8
    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
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  • 9
    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.
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  • 10
    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.
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  • 11
    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.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Journal of biomedical science 1 (1994), S. 201-203 
    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.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1671-1678 
    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.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 153 (1994), S. 372-377 
    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.
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  • 15
    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).
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 88 (1994), S. 754-758 
    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.
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  • 17
    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.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 89 (1994), S. 313-317 
    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.
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  • 19
    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).
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical crystallography 24 (1994), S. 759-762 
    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.
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  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical crystallography 24 (1994), S. 437-440 
    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.
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  • 22
    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.
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  • 23
    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.
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  • 24
    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.
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  • 25
    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.
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  • 26
    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.
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  • 27
    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.
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  • 28
    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.
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  • 29
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    Journal of neurology 241 (1994), S. 487-491 
    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.
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  • 30
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    European archives of psychiatry and clinical neuroscience 244 (1994), S. 138-140 
    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.
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  • 31
    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.
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  • 32
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    European journal of epidemiology 10 (1994), S. 317-324 
    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.
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  • 33
    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.
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  • 34
    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.
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  • 35
    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.
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  • 36
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    Journal of chemical crystallography 24 (1994), S. 731-737 
    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.
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  • 37
    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.
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  • 38
    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.
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  • 39
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    Journal of inclusion phenomena and macrocyclic chemistry 20 (1994), S. 53-71 
    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.
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  • 40
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    Journal of inclusion phenomena and macrocyclic chemistry 17 (1994), S. 137-148 
    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.
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  • 41
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    Journal of inclusion phenomena and macrocyclic chemistry 17 (1994), S. 187-201 
    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.
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  • 42
    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.
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  • 43
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    Journal of inclusion phenomena and macrocyclic chemistry 17 (1994), S. 365-376 
    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.
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  • 44
    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.
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  • 45
    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).
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  • 46
    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.
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  • 47
    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.
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  • 48
    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.
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  • 49
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 19 (1994), S. 4-13 
    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.
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  • 50
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 20 (1994), S. 149-166 
    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.
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  • 51
    Electronic Resource
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    Springer
    Behavioral ecology and sociobiology 35 (1994), S. 99-107 
    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.
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  • 52
    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.
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  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Russian chemical bulletin 43 (1994), S. 1384-1389 
    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.
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  • 54
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    Springer
    Metabolic brain disease 9 (1994), S. 105-131 
    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.
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  • 55
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    Journal of sol gel science and technology 1 (1994), S. 113-121 
    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.
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  • 56
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    Behavioral ecology and sociobiology 34 (1994), S. 117-409 
    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.
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  • 57
    Electronic Resource
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    Springer
    Behavioral ecology and sociobiology 35 (1994), S. 99-107 
    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.
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  • 58
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    Springer
    Behavioral ecology and sociobiology 34 (1994), S. 125-137 
    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.
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  • 59
    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.
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  • 60
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 2289-2306 
    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.
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  • 61
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 851-857 
    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.
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  • 62
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 2653-2659 
    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.
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  • 63
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1479-1482 
    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.
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  • 64
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 703-706 
    ISSN: 0044-2313
    Keywords: SmIII dimeric complex ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Reaction of Dilithiumbiphenyl with SmBr3. The Crystal Structure of [(C24H16)SmBr(thf)2]2 · [C24H14]In THF SmBr3 forms with [(biph)Li2] the dimeric complex [(quaph)SmBr(thf)2]2 · [C24H14]. The structure was characterized by X-ray single crystal structure analysis (space group P1 (No. 2), Z = 1, a = 943.3(6) pm, b = 1 350.3(1) pm, c = 1 599.9(9) pm, α = 64.99(5)°, β = 89.02(5)°, γ = 73.02(6)°). The Sm iones are bridged by two Br iones. Coordination by one quaph and THF ligands leads to distorded octahedra coordination of the Sm iones. Additionally crystallizes one molecule dibenzonaphthacene.
    Notes: SmBr3 reagiert mit [(biph)Li2] in THF zu dem zweikernigen Komplex [(quaph)SmBr(thf)2]2 · [C24H14]. Der Aufbau konnte durch eine Kristallstrukturanalyse geklärt werden (Raumgruppe P1 (Nr. 2), Z = 1, a = 943,3(6) pm, b = 1 350,3(1) pm, c = 1 599,9(9) pm, α = 64,99(5)°, β = 89,02(5)°, γ = 73,02(6)°). Die Sm-Ionen werden durch zwei Br-Ionen verbrückt. Durch zusätzliche Koordination eines quaph- und zweier THF-Liganden ist jedes Sm-Ion verzerrt oktaedrisch koordiniert. Zusätzlich kristallisiert ein Molekül Dibenzonaphthacen mit aus.
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  • 65
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 723-729 
    ISSN: 0044-2313
    Keywords: Dimethyltin dithiosquarate benzene solvate ; Dimethyltin dithiosquarate-dimethylsulfoxide adduct ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimethyltin Dithiosquarate: The Crystal Structure of the Benzene Solvate and of the Dimethylsulfoxide Adduct(CH3)2SnS2C4O2 · 1/3 C6H6 (I) crystallizes in the orthorhombic space group Pnma. a = 14.393(2), b = 21.668(3), c = 10.424(1) Å, Z = 12.(CH3)2SnS2C4O2 · (CH3)2SO (II) is monoclinic, space group P21/n, a = 9.918(5), b = 12.028(6), c = 12.223(6) Å, β = 108.82(3)°, Z = 4.In I there are two independent dimethyltin dithiosquarate molecules. But in both molecules the Sn atoms display weak coordinative bonds to two O atoms of adjacent dithiosquarate groups. The distances amount 2.873 Å (2×), resp. 2.678 and 2.831 Å. The coordination number of tin becomes 6 and the structure gets connected in three dimensions.In II dimethylsulfoxide is bound with the O atom to Sn (2.345 Å) and the result is a distorted trigonal bipyramid. There a more distant O atom (2.944 Å) leads to a connection of the molecules to a ribbon. The changes of the geometrical parameters are described, which result from the progressive approach of the one O atom.
    Notes: (CH3)2SnS2C4O2 · 1/3 C6H6 (I) kristallisiert in der orthorhombischen Raumgruppe Pnma; a = 14,393(2); b = 21,668(3); c = 10,424(1) Å; Z = 12.(CH3)2SnS2C4O2 · (CH3)2SO (II) ist monoklin, Raumgruppe P21/n; a = 9,918(5); b = 12,028(6); c = 12,223(6) Å; β = 108,82(3)°; Z = 4.In I liegen zwei kristallographisch unabhängige Dimethyl-zinndithioquadratat-Moleküle vor. Bei beiden weisen jedoch die Sn-Atome schwache koordinative Bindungen zu zwei O-Atomen benachbarter Dithioquadratat-Gruppen auf. Die Abstände betragen 2,873 Å (2×) bzw. 2,678 und 2,831 Å. Dadurch erhält Zinn die Koordinationszahl 6, und es ergibt sich eine dreidimensional vernetzte Struktur.In II ist Dimethylsulfoxid über das O-Atom an Sn gebunden (2,345 Å), und es liegt eine verzerrte trigonale Bipyramide vor. Ein weiter entferntes O-Atom (2,944 Å) bewirkt hier die Vernetzung der Moleküle zu einem Band. Die Veränderungen der geometrischen Parameter als Folge der fortschreitenden Annäherung des einen O-Atoms werden beschrieben.
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  • 66
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 733-736 
    ISSN: 0044-2313
    Keywords: Manganese(II) oxotungstate ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On a New Manganese(II) Oxotungstate: Mn3WO6Single crystals of Mn3WO6 were prepared by CO2-LASER technique in H2-atmosphere and investigated by single crystal X-ray work. It crystallizes with rhombohedral symmetry, space group C3i2—R3 with the hexagonal lattice constants a = 8.8931 Å; c = 10.4782 Å and Z = 6. Mn3WO6 is isotypic to Mg3TeO6 and α-Ca3UO6 and characterized by to each other isolated WO6 octahedra. The surrounding of them by six inner-sphere and six outer-sphere MnO6 polyhedra is discussed.
    Notes: Mn3WO6 wurde mit CO2-LASER-Technik in H2-Atmosphäre einkristallin dargestellt und röntgenographisch untersucht. Es kristallisiert rhomboedrisch in der Raumgruppe C3i2—R3 mit a = 8,8931 Å; c = 10,4782 Å und Z = 6. Mn3WO6 ist isotyp zu Mg3TeO6 und α-Ca3UO6 und durch isolierte Oktaeder WO6 ausgezeichnet. Deren Umgebung durch sechs Polyeder MnO6 in „innerer“ und sechs weiterer in äußerer Sphäre wird diskutiert.
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  • 67
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 737-742 
    ISSN: 0044-2313
    Keywords: Indium ; tris(N,N-diethyl-N′-benzoylselenoureato)indium(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)indium(III)In(C12H15N2OSe)3 crystallizes in the monoclinic space group P21/c. The cell parameters are a = 11.792(2), b = 36.797(4), c = 18.574(2) Å, β = 92.15(2)° and Z = 4. The structure was solved with Patterson and direct methods and was refined to a final R-value of 3.41%. The asymmetric unit contains two complex molecules. The indium atoms are bidentally coordinated by three N,N-Diethyl-N′-benzoylselenourea molecules to form distorted octahedra with facial arrangement of the selenium and oxygen donor atoms. The chelate rings diverge strongly from planarity. The In—Se bond lengths vary from 2.643(1) to 2.657(1) Å, the In—O bond lengths from 2.179(4) to 2.203(4) Å, respectively.
    Notes: In(C12H15N2OSe)3 kristallisiert in der monoklinen Raumgruppe P21/c mit den Gitterkonstanten a = 11,792(2), b = 36,797(4), c = 18,574(2) Å, β = 92,15(2)°, Z = 4. Die Struktur wurde mit Patterson und Direkten Methoden gelöst und bis zu einem R-Wert von 3,41% verfeinert. In der asymmetrischen Einheit befinden sich zwei In(C12H15N2OSe)3-Komplexmoleküle. Jeweils drei N,N-Diethyl-N′-benzoylseleno-harnstoff-Moleküle sind bidental über Selen- und Sauerstoffatome an die Zentralatome koordiniert. Das Koordinationspolyeder ist ein verzerrter Oktaeder mit facialer Anordnung der Donoratome. Die Chelatringe weichen deutlich von der Planarität ab. Die In—Se-Abstände in den beiden Oktaedern liegen zwischen 2,643(1) und 2,657(1) Å, die In—O-Abstände variieren von 2,179(4) bis 2,203(4) Å.
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  • 68
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    Zeitschrift für anorganische Chemie 620 (1994), S. 1781-1785 
    ISSN: 0044-2313
    Keywords: Nitridocobaltate ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ba[CoN]: A Low-Valency Nitridocobaltate with Angled Chains ∞1[CoN2/22-]Ba[CoN] is prepared by reaction of barium and cobalt (molar ratio Ba : Co = 1 : 2.5) in tantalum crucibles at 870°C with flowing nitrogen (1 atm) within a period of 96 h. After cooling down to room temperature (24°C/h) black single crystals of the ternary phase with a platy habit are obtained (orthorhombic, Pnma; a = 959.9(2) pm, b = 2 351.0(3) pm, c = 547.6(2) pm; Z = 20). The crystal structure of Ba[CoN] contains angled (planar) chains ∞1[CoN2/22-] which run along the [010]-direction (N—Co—N[°]: 178.5(5), 179.6(6), 180.0; Co—N—Co[°]: 82.9(6), 84.2(5), 177.1(8); Co—N[pm]: 174.6(12), 177.2(12), 181.9(13), 184.3(13), 187.1(12)). Nitrogen is in an octahedral coordination (N Ba4Co2) and is arranged in a distorted cubic close packing. Barium occupies one half of the tetrahedral holes (Ba—N[pm]: 274.8(16) - 308.2(12)). The cis-positions of the Co-atoms at the nitrogen coordination-octahedra cause short Co—Co contacts within the chains ∞1[CoN2/22-]. Through this, Co2-units (Co—Co[pm]: 247.8(4); bridged by nitrogen) and linear Co3-groups (Co—Co [pm]: 245.5(2); Co—Co—Co[°]: 180.0; bridged by nitrogen) alternate along the chains.The crystal structure of Ba[CoN] is closely related to the Ba[NiN] type structure.
    Notes: Ba[CoN] wird durch Umsetzung von Barium und Cobalt im molaren Verhältnis Ba: Co = 1 : 2,5 bei 870°C im Tantaltiegel mit strömendem Stickstoff (1 atm) dargestellt. Die Reaktionszeit beträgt 96 h. Nach Abkühlen auf Raumtemperatur (24°C/h) liegt die ternäre Phase in Form schwarzer Einkristalle mit plattigem Habitus vor (orthorhombisch, Pnma; a = 959,9(2) pm, b = 2 351,0(3) pm, c = 547,6(2) pm; Z = 20). Die Kristallstruktur von Ba[CoN] enthält gewinkelte (ebene) Ketten ∞1[CoN2/22-], die entlang [010] verlaufen (N—Co—N[°]: 178,5(5), 179,6(6), 180,0; Co—N—Co[°]: 82,9(6), 84,2(5), 177,1(8); Co—N[pm]: 174,6(12), 177,2(12) 181,9(13), 184,3(13), 187,1(12)). Stickstoff ist oktaedrisch koordiniert (N Ba4Co2) und bildet das Motiv einer verzerrt kubisch dichtesten Packung. Barium besetzt eine Hälfte der Tetraederlücken (Ba—N[pm]: 274,8(16) - 308,2(12)). Die cis-Positionierung der Co-Atome an den Stickstoff-Koordinationsoktaedern bedingt kurze Co—Co-Abstände innerhalb der Ketten ∞1[CoN2/22-], so daß von Stickstoff überbrückte Co2-Einheiten (Co—Co[pm]: 247,8(4)) und gestreckte, von Stickstoff überbrückte Co3-Gruppen (Co—Co[pm]: 245,5(2); Co—Co—Co[°]: 180,0) in Kettenrichtung alternierend aufeinanderfolgen.Die Kristallstruktur von Ba[CoN] zeigt enge Verwandtschaft zum Ba[NiN]-Typ.
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  • 69
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1812-1817 
    ISSN: 0044-2313
    Keywords: Chloro, oxo and thiotantalum(V) compounds ; syntheses ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxo- and Thiotantalum(V) Compounds: Synthesis of TaOX3 and TaSX3 (X = OR, SR)TaO(OR)3 [R = tC4H9, Mes* (2)], TaO(SR)3 [R = tC4H9, p-Tolyl], TaS(OR)3 [R = tC4H9, Mes* (6)] and TaS(SR)3 [R = tC4H9, p-Tolyl] have been prepared by reaction of TaOCl3 and TaSCl3 with LiOR or LiSR. The reaction of TaCl5 with an excess of LiOMes* yields the chlorotantalum(V)compounds TaCl3(OMes*)2 and TaCl2(OMes*)3 (10). The synthesis of TaCl2(nC4H9)(OMes*)2 (11), Ta(Sp-Tolyl)5 and TaCl2(OEt)3 · C5H5N are also described. 2, 6, 10 and 11 decompose in benzolic solution or by heating under vacuum splitting off 2,4,6-tri-tert-butyl-phenol, n-butane respectively, and forming cyclometallated tantalum(V) complexes with the bidentate ligand OC6H2tBu2CMe2CH2. TaCl2(OEt)3 was investigated by X-ray diffraction analysis; the crystal structure has been found to be a binuclear tantalum complex with two bridging ethoxo ligands.
    Notes: TaO(OR)3 [R = tC4H9, Mes* (2)], TaO(SR)3 [R = tC4H9, p-Tolyl], TaS(OR)3 [R = tC4H9, Mes* (6)] und TaS(SR)3[ R = tC4H9, p-Tolyl] werden dargestellt durch Reaktion von TaOCl3 und TaSCl3 mit LiOR oder LiSR. Die Umsetzung von TaCl5 mit überschüssigem LiOMes* führt zu den Chlorotantal(V)-Verbindungen TaCl3(OMes*)2 und TaCl2(OMes*)3 (10). Darüber hinaus wird die Synthese von TaCl2(nC4H9)(OMes*)2 (11), Ta(Sp-Tolyl)5 und TaCl2(OEt)3 · C5H5N beschrieben. 2, 6, 10 und 11 zersetzen sich in benzolischer Lösung oder beim Erhitzen i. Vak. unter Abspaltung von 2,4,6-Tri-tert-butyl-phenol bzw. n-Butan und Bildung von cyclometallierten Tantal(V)-Verbindungen mit dem zweizähnigen Liganden OC6H2tBu2CMe2CH2. Die Kristallstruktur von TaCl2(OEt)3 wurde bestimmt; im zweikernigen Komplex sind die Tantalatome über zwei Ethoxo-Liganden verbrückt.
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  • 70
    ISSN: 0044-2313
    Keywords: Cyclotriphosphanes ; transition metal carbonyl complexes of Fe, Co, Ir, and Ni ; phosphorus-bridged ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Structure of the Phosphorus-bridged Transition Metal Complexes [Fe2(CO)6(PR)6] (R = tBu, iPr), [Fe2(CO)4(PiPr)6], [Fe2(CO)3Cl2(PtBu)5], [Co4(CO)10(PiPr)3], [Ni5(CO)10(PiPr)6], and [Ir4(C8H12)4Cl2(PPh)4](PtBu)3 and (PiPr)3 react with [Fe2(CO)9] to form the dinuclear complexes [Fe2(CO)6(PR)6] (R = tBu: 1; iPr: 2). 2 is also formed besides [Fe2(CO)4(PiPr)6] (3) in the reaction of [Fe(CO)5] with (PiPr)3. When PiPr(PtBu)2 and PiPrCl2 are allowed to react with [Fe2(CO)9] it is possible to isolate [Fe2(CO)3Cl2(PtBu)5] (4). The reactions of (PiPr)3 with [Co2(CO)8] and [Ni(CO)4] lead to the tetra- and pentanuclear clusters [Co4(CO)10(PiPr)3] (5), [Ni4(CO)10(PiPr)6] [2] and [Ni5(CO)10(PiPr)6] (6). Finally the reaction of [Ir(C8H12)Cl]2 with K2(PPh)4 leads to the complex [Ir4(C8H12)4Cl2(PPh)4] (7). The structures of 1-7 were obtained by X-ray single crystal structure analysis (1: space group P21/c (Nr. 14), Z = 8, a = 1 758.8(16) pm, b = 3 625.6(18) pm, c = 1 202.7(7) pm, β = 90.07(3)°; 2: space group P1 (Nr. 2), Z = 1, a = 880.0(2) pm, b = 932.3(3) pm, c = 1 073.7(2) pm, α = 79.07(2)°, β = 86.93(2)°, γ = 72.23(2)°; 3: space group Pbca (Nr. 61), Z = 8, a = 952.6(8) pm, b = 1 787.6(12) pm, c = 3 697.2(30) pm; 4: space group P21/n (Nr. 14), Z = 4, a = 968.0(4) pm, b = 3 362.5(15) pm, c = 1 051.6(3) pm, β = 109.71(2)°; 5: space group P21/n (Nr. 14), Z = 4, a = 1 040.7(5) pm, b = 1 686.0(5) pm, c = 1 567.7(9) pm, β = 93.88(4)°; 6: space group Pbca (Nr. 61), Z = 8, a = 1 904.1(8) pm, b = 1 959.9(8) pm, c = 2 309.7(9) pm. 7: space group P1 (Nr. 2), Z = 2, a = 1 374.4(7) pm, b = 1 476.0(8) pm, c = 1 653.2(9) pm, α = 83.87(4)°, β = 88.76(4)°, γ = 88.28(4)°).
    Notes: Die Cyclotriphosphane (PtBu)3 und (PiPr)3 reagieren mit [Fe2(CO)9] unter Bildung der Zweikernkomplexe [Fe2(CO)6(PR)6] (R = tBu: 1; iPr: 2). 2 entsteht auch bei der Reaktion von [Fe(CO)5] mit (PiPr)3 neben dem Komplex [Fe2(CO)4(PiPr)6] (3). Aus der Reaktion von PiPr(PtBu)2 und PiPrCl2 mit [Fe2(CO)9] kann weiterhin [Fe2(CO)3Cl2(PtBu)5] (4) isoliert werden. Die Umsetzungen von (PiPr)3 mit [Co2(CO)8] und [Ni(CO)4] führen zu den vier- und fünfkernigen Clustern [Co4(CO)10(PiPr)3] (5), [Ni4(CO)10(PiPr)6] [2] und [Ni5(CO)10(PiPr)6] (6). Weiterhin kann aus der Reaktion von [Ir(C8H12)Cl]2 mit K2(PPh)4 der Komplex [Ir4(C8H12)4Cl2(PPh)4] (7) erhalten werden. Die Strukturen von 1-7 konnten durch Einkristall-Röntgenstrukturanalyse aufgeklärt werden (1: Raumgruppe P21/c (Nr. 14), Z = 8, a = 1 758,8(16) pm, b = 3 625,6(18) pm, c = 1 202,7(7) pm, β = 90,07(3)°; 2: Raumgruppe P1 (Nr. 2), Z = 1, a = 880,0(2) pm, b = 932,3(3) pm, c = 1 073,7(2) pm, α = 79,07(2)°, β = 86,93(2)°, γ = 72,23(2)°; 3: Raumgruppe Pbca (Nr. 61), Z = 8, a = 952,6(8) pm, b = 1 787,6(12) pm, c = 3 697,2(30) pm; 4: Raumgruppe P21/n (Nr. 14), Z = 4, a = 968,0(4) pm, b = 3 362,5(15) pm, c = 1 051,6(3) pm, β = 109,71(2)°; 5: Raumgruppe P21/n (Nr. 14), Z = 4, a = 1 040,7(5) pm, b = 1 686,0(5) pm, c = 1 567,7(9) pm, β = 93,88(4)°; 6: Raumgruppe Pbca (Nr. 61), Z = 8, a = 1 904,1(8) pm, b = 1 959,9(8) pm, c = 2 309,7(9) pm. 7: Raumgruppe P1 (Nr. 2), Z = 2, a = 1 374,4(7) pm, b = 1 476,0(8) pm, c = 1 653,2(9) pm, α = 83,87(4)°, β = 88,76(4)°, γ = 88,28(4)°).
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  • 71
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    Zeitschrift für anorganische Chemie 620 (1994), S. 1137-1141 
    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.
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  • 72
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 2026-2032 
    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.
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  • 73
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 2064-2069 
    ISSN: 0044-2313
    Keywords: RbNa3Li12[TiO4]4 ; orthotitanate ; crystal structure ; MAPLE ; CHARDI ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The First Titanate with „Stuffed Pyrgoms“: RbNa3Li12[TiO4]4 = RbNa3Li8{Li[TiO4]}4By heating a well grounded mixture of the binary oxides Rb2O, Na2O, Li2O, and TiO2 [Rb:Na:Li:Ti = 1.1:3.1:12.5:4.0; 780°C, 41 d] we obtained RbNa3Li8{Li[TiO4]}4 as colourless platelike crystals. This first titanate with „stuffed pyrgoms“ is isostructural with RbNa3Li8{Li[SiO4]}4, CsKNa2Li8{Li[SiO4]}4 and CsKNaLi9{Li[SiO4]}4 [2]. The compound crystallizes tetragonal I4/m with a = 1 125.8(1) pm and c = 652.4(1) pm (Guinier-Simon-Data, Z = 2). The structure was determined by four-cyrcle-data (Siemens AED2, MoKα-) and leds to the residual values R = 3.7% and Rw = 3.1% (additional data see text). The Madelung Part of Lattice Energy (MAPLE), Effective Coordination Numbers (ECoN), Mean Fictive Ionic Raddii (MEFIR) and the Charge Distribution in Solids (CHARDI) are calculated and discussed.
    Notes: Durch Tempern eines innigen Gemenges der binären Oxide Rb2O, Na2O, Li2O und TiO2 [Rb:Na:Li:Ti = 1,1:3,1:12,5:4,0; 780°C, 41 d] wurde RbNa3Li8{Li[TiO4]}4 in Form von farblosen Plättchen erhalten. Das erste Titanat mit „stuffed pyrgoms“ ist isotyp zu RbNa3Li8{Li[SiO4]}4, CsKNa2Li8{Li[SiO4]}4 und CsKNaLi9{Li[SiO4]}4 [2]. Die Verbindung kristallisiert tetragonal I4/m mit den Gitterkonstanten a = 1 125,8(1) pm und c = 652,4(1) pm (Guinier-Simon-Daten, Z = 2). Die Struktur wurde mit Vierkreisdiffraktometerdaten (Siemens AED2, 657Io(hkl), MoKα-) aufgeklärt und führte zu den Residualwerten R = 3,7% und Rw = 3,1% (weitere Daten siehe Text). Der Madelunganteil der Gitterenergie (MAPLE), Effektive Koordinationszahlen (ECoN), Mittlere Fiktive Ionenradien (MEFIR) sowie die Ladungsverteilung (CHARDI) werden berechnet und diskutiert.
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  • 74
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1132-1136 
    ISSN: 0044-2313
    Keywords: Cyanuric chloride ; FPDE values ; crystal structure ; chlorotrifluoro methane ; oxidative fluorinators ; ab initio computations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Fluorination of Cyanuric Chloride and Low-Temperature Crystal Structure of [(ClCN)3F]+[AsF6]-The low-temperature fluorination of cyanuric chloride, (ClCN)3, with F2/AsF5 in SO2F2 solution yielded the salt [(ClCN)3F]+ [AsF6]- (1) essentially in quantitative yield. Compound 1 was identified by a low-temperature single crystal X-ray structure determination: R 3c, trigonal, a = b = 10.4246(23) Å, c = 15.1850(24) Å, V = 1429.1(4) Å 3, Z = 6, RF = 0.056, Rw = 0.076 (for significant reflections), RF = 0.088, Rw = 0.079 (for all reflections). Fluorination of neat (ClCN)3 with [NF4]+ [Sb2F11]- yielded NF3, CClF3, SbF3, N2 and traces of CF4. A qualitative scale for the oxidizing strength of the oxidative fluorinators NF4+ and (XCN)3F+ (X = H, F, Cl) has been computed ab initio.
    Notes: Durch Tieftemperaturfluorierung von Cyanurchlorid, (ClCN)3, mit F2/AsF5 in SO2F2-Lösung wurde [(ClCN)3F]+ [AsF6]- (1) in nahezu quantitativer Ausbeute dargestellt, aus SO2 bei Raumtemperatur umkristallisert und durch eine Tieftemperatur-Röntgenstrukturanalyse (-170°C) identifiziert: R 3c, trigonal, a = b = 10,4246(23) Å, c = 5,1850(24) Å, V = 1 429,1(4) Å3, Z = 6, RF = 0,056, Rw = 0,076 (für wesentliche Reflexionen), RF = 0,088, Rw = 0,079 (für alle Reflexe). Die Fluorierung von festem (ClCN)3 mit [NF4]+ [Sb2F11]- im Molverhältnis 1:2 lieferte NF3, CClF3, SbF3, N2 und Spuren an CF4. Eine qualitative Reihenfolge bezüglich der FPDE-Werte von NF4+ und (XCN)3F+ (X = H, F, Cl) wurde ab initio berechnet.
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  • 75
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 323-325 
    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.
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  • 76
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 805-808 
    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.
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  • 77
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 814-818 
    ISSN: 0044-2313
    Keywords: GdIII and SmIII octahedra complexes ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Complexes of the Lanthanoides with Bidentate Ligands. The Crystal Structures of [(C17H17N2)GdBr2(thf)2] and [(C17H17N2)3Ln] (L = Sm, Gd)Reaction of [(AIP)Li] with GdBr3 leads to a new mononuclear complex [(AIP)GdBr2(thf)2] 1. In contrast to this with SmI2 the compound [(AIP)3Sm] 2 is build up. Such complexes are also formed with Gd(OR*)3 (R* = OtBu2C6H3) and [(AIP)Li] in a 1:3 ratio, [(AIP)3Gd] 3. The structures of 1-3 were characterized by X-ray single crystal structure analysis (1: space group Pna21 (No. 33), Z = 4, a = 1 972.7(9) pm, b = 984.7(5) pm, c = 1 425.0(8) pm, α = β = γ = 90°; 2 · 2 THF: space group C2/c (No. 15), Z = 8, a = 3 644.4(9) pm, b = 1 437.5(5) pm, c = 2 334.4(7) pm, β = 1 21.07(6)°; 3: space group P2(1)/c (No. 14), Z = 4, a = 1 872.9(1) pm, b = 1 064.6(1) pm, c = 2 282.4(2) pm, β = 103.75(8)°).
    Notes: GdBr3 reagiert mit [(AIP)Li] zu dem einkernigen Komplex [(AIP)GdBr2(thf)2] 1. Mit SmI2 bildet sich dagegen überraschenderweise die Komplexverbindung [(AIP)3Sm] 2. Komplexe dieser Art bilden sich auch bei der Umsetzung von Gd(OR*)3 (R* = OtBu2C6H3) mit [(AIP)Li] im Verhältnis 1:3, [(AIP)3Gd] 3. Der Aufbau von 1-3 konnte durch Kristallstrukturanalyse geklärt werden (1: Raumgruppe Pna21 (Nr. 33), Z = 4, a = 1 972,7(9) pm, b = 984,7(5) pm, c = 1 425,0(8) pm, α = β = γ = 90°; 2 · 2 THF: Raumgruppe C2/c (Nr. 15), Z = 8, a = 3 644,4(9) pm, b = 1 437,5(5) pm, c = 2 334,4(7) pm, β = 1 21,07(6)°; 3: Raumgruppe P2(1)/c (Nr. 14), Z = 4, a = 1 872,9(1) pm, b = 1 064,6(1) pm, c = 2 282,4(2) pm, β = 103,75(8)°).
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  • 78
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 847-850 
    ISSN: 0044-2313
    Keywords: Diorganoindium cations ; syntheses ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Diorganoindium Cations. The Crystal Structure of [Mes2In][BF4](PhCH3)2In and Mes3In react with BF3 · OEt2 in a ratio of 3:4 at 80°C in toluene to the corresponding salts [R2In][BF4] [R = PhCH2 (1), Mes (2)]. The same results could be obtained, when the diorganoindium fluorides (PhCH2)2InF and Mes2InF were treated with BF3 · OEt2 at 80°C in toluene. 1 und 2 were characterized by NMR-, IR- und MS-techniques. The arrangement of the ions in 2 could be established by an X-ray structure determination. The cations and anions of 2 are forming infinite chains. The metal centers are coordinated by two BF4--ions, so that every In atom possesses a distorted octahedral coordination sphere.
    Notes: (PhCH2)3In und Mes3In reagieren mit BF3 · OEt2 im Verhältnis 3:4 bei 80°C in Toluol zu den entsprechenden Salzen [R2In][BF4] [R = PhCH2 (1), Mes (2)]. Zum selben Ergebnis gelangt man, wenn die Diorganoindiumfluoride (PhCH2)2InF und Mes2InF mit BF3 · OEt2 bei 80°C in Toluol behandelt werden. 1 und 2 wurden mittels NMR- und IR-Spektroskopie sowie Massenspektrometrie charakterisiert. Die Anordnung der Ionen in 2 konnte durch eine Röntgenstrukturanalyse aufgeklärt werden. 2 bildet danach unendliche Ketten aus Kationen und Anionen, wobei durch eine chelatartige Anordnung zweier BF4--Ionen an jedes Metallzentrum eine verzerrt oktaedrische Koordinationssphäre der Indiumatome resultiert.
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  • 79
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1664-1668 
    ISSN: 0044-2313
    Keywords: Dirhenium complex anion ; rheniummolybdenum complex anion ; NMR data ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Insertion of a Terminal Halogeno Ligand into Diorgano-bridged Dirhenium and Rhenium-Molybdenum Complex Anions in the Presence of an Amidin Cation and the Isomerization ProcessesThe equimolar reaction of in situ generated anion Anions Re2(μ-PCy2)(CO)8- (Re—Re) in the presence of a steric expansive amidine cation DBUH+ with bromine and iodine in tetrahydrofuran solution gave the two isomers Re2(PCy2)(CO)8X (Re—Re) and Re2(μ-PCy2)(μ-X)(CO)8 (X = Br, I), of which the isomer with a terminal X ligand as major product was formed under maintenance of the Re—Re bond. The monotropic isomerization process of Re2(μ-PCy2)(CO)8I runs thermically relative slowly, but more rapid in photochemical and electrochemical processes. The analogeous reaction of the heterometallic anion ReMo(η5-C5H5)(μ-PPh2)(CO)6- with iodine delivers opposite to the former reaction mainly the bridged isomer ReMo(η5-C5H5)(μ-PPh2μ-I)(CO)6 besides ReMo(η5-C5H5)(μ-PPh2)(CO)6I. The obtained complexes were characterized by means of v(CO) and 31P NMR spectroscopic measurements. Single-crystal analyses led to the subsequent metal - metal bond lengths: Re—Re of 308.0(1) pm in Re2(μ-PCy2)(CO)8Br and Re—Mo of 313.6(1) pm in ReMo(η5-C5H5)(μ-PPh2)(CO)6I.
    Notes: Die äquimolare Umsetzung des in situ gebildeten Anions Re2(μ-PCy2)(CO)8 (Re—Re) in Gegenwart eines sterisch anspruchsvollen Amidinkations DBUH+ mit Brom und Jod in Tetrahydrofuranlösung bei 20°C ergab jeweils von beiden Isomeren Re2(μ-PCy2)(CO)8X (Re—Re) und Re2(μ-PCy2)(μ-X)(CO)8 (X = Br, I) überwiegend dasjenige mit terminal gebundenem Halogenoliganden unter Aufrechterhaltung der Re—Re-Bindung. Die monotrope Isomerisierung von Re2(μ-PCy2)(CO)8I verläuft thermisch relativ langsam, aber photochemisch und elektrochemisch schneller. Die analoge Umsetzung des heterometallischen Anions ReMo(η5-C5H5)(μ-PPh2)(CO)6 mit Jod lieferte demgegenüber bevorzugt das verbrückte Isomer ReMo(η5-C5H5)(μ-PPh2)(μ-I)(CO)6 neben ReMo(η5-C5H5)(μ-PPh2)(CO)6I. Die erhaltenen Komplexe wurden durch v(CO)- und 31P NMR-spektroskopische Daten charakterisiert. Einkristall-Röntgenstrukturanalysen führten zu folgenden Metall - Metall-Bindungslängen: Re—Re von 308,0(1) pm in Re2(μ-PCy2)(CO)8Br und Re—Mo von 313,6(1) pm in ReMo(η5-C5H5)(μ-PPh2)(CO)6I.
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  • 80
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1023-1027 
    ISSN: 0044-2313
    Keywords: Dysprosium halide complexes ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cationic and Anionic Edge-Connected Dimers in [Dy2(dibenzo-18-crown-6)2Cl4][Dy2(CH3CN)2Cl8]. Synthesis and Crystal StructureColourless single crystals of 2 DyCl3 · dibenzo-18-crown-6 · CH3CN are obtained upon reaction of DyCl3 or KDy2Cl7 with dibenzo-18-crown-6-ether in acetonitrile. The crystal structure (triclinic, P1, Z = 2; a = 1 105.6(2); b = 1 144.5(3); c = 1 367.8(3); α = 93.46(1); β = 92.27(1); γ = 117.45(1); R = 0.046; Rw = 0.033) contains cationic and anionic edge-connected dimers according to [Dy2(dibenzo-18-crown-6)2Cl4]2+ [Dy2(CH3CN)2Cl8]2+ where Dy1 and Dy2 are coordinated by 3 and 5 chloride ions, respectively.
    Notes: Bei der Umsetzung von DyCl3 oder KDy2Cl7 mit Dibenzo-18-Krone-6-Ether in Acetonitril werden farblose Kristalle der Zusammensetzung 2 DyCl3 · Dibenzo-18-Krone-6 · CH3CN erhalten. Die Kristallstruktur (triklin, P1, Z = 2; a = 1 105,6(2); b = 1 144,5(3); c = 1 367,8(3); α = 93,46(1); β = 92,27(1); γ = 117,45(1); R = 0,046; Rw = 0,033) enthält kationische und anionische, jeweils kantenverknüpfte Dimere gemäß [Dy2(Dibenzo-18-Krone-6)2Cl4]2+ [Dy2(CH3CN)2Cl8]2+, in denen Dy1 und Dy2 gegenüber Cl- die Koordinationszahlen 3 bzw. 5 aufweisen.
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  • 81
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1051-1055 
    ISSN: 0044-2313
    Keywords: Copper cobalt borate oxide, Cu2Co(B2O5)O ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On a New Copper Cobalt Borate Oxide with Isolated B2O5 Units: Cu2Co(B2O5)OSingle crystals of a new compound with the empirical formula Cu2CoB2O6 were obtained by using a B2O3 flux technique. X-ray single crystal technique led to a new structure type. Cu2CoB2O6 crystallizes monoclinic, space group C2h5-P21/c (No. 14); a = 3.2250(6); b = 14.847(1); c = 9.1171(6) Å; β = 93.67°; Z = 4. All metal sites are octahedrally coordinated and form a two dimensional framework consisting of edge sharing octahedra ribbons. In addition one observes isolated B2O5-units and oxygen which is not coordinated to boron. The far relation to the crystal structure of the mineral Warwickite is illustrated.
    Notes: Unter Verwendung einer B2O3-Schmelze gelang die Synthese von Einkristallen einer Substanz mit der Summenformel Cu2CoB2O6, die einen eigenständigen, neuartigen Strukturtyp bildet. Sie kristallisiert in der Raumgruppe C2h5-P21/c (No. 14), a = 3,2250(6); b = 14,847(1); c = 9,1171(6) Å; β = 93,67(2)°; Z = 4. Die Metallkationen sind verzerrt oktaedrisch koordiniert und bilden durch Kantenverknüpfungen der Polyeder in zwei Richtungen ein Netzwerk aus Oktaederbändern. Die Struktur weist isolierte B2O5-Baugruppen auf und zudem Sauerstoff, der nicht an Bor gebunden ist. Eine entfernte Verwandtschaft zur Kristallstruktur des Minerals Warwickit wird aufgezeigt.
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  • 82
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 2003-2007 
    ISSN: 0044-2313
    Keywords: Samarium nitride sulfide ; Sm4N2S3 ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Samarium Nitride Sulfide: Sm4N2S3The oxidation of samarium with sulfur in the presence of SmCl3 and NaN3 as nitrogen source (molar ratio: 12:9:4:2, evacuated silica vessel, some NaCl as flux, 850°C, 7 d) yields Sm4N2S3 as lath-shaped, dark red single crystals. The by-products (NaCl and NaSm2Cl6) are rinsed with water from the crude product.The crystal structure of Sm4N2S3 (monoclinic, C2/m (no. 12), Z = 2, a = 1 318.04(12), b = 391.57(2), c = 1 031.76(9) pm, β = 130.874(6)°, R = 0.036, Rw = 0.031) contains two crystallographically different Sm3+, both in sixfold coordination of the anions. Besides distorted octahedra [(Sm1)N3S3] and [(Sm2)NS5], tetrahedra [(N3-)(Sm43+)] connected via two cis-oriented edges to form chains ∞1[N(Sm1)3/3(Sm2)1/1]3+ build up the Mayn structural feature. These are arranged in the fashion of a closest packing of rods and held together by two crystallographically different S2- anions which take care for charge neutrality and three-dimensional interconnection.
    Notes: Bei der Oxidation von Samarium mit Schwefel in Gegenwart von SmCl3 und NaN3 als Stickstoff-Quelle (molares Verhältnis: 12:9:4:2, evakuierte Quarzglasampulle, etwas NaCl als Flußmittel, 850°C, 7 d) fällt Sm4N2S3 in Form von stäbchenförmigen, dunkelroten Einkristallen an. Die Nebenprodukte (NaCl und NaSm2Cl6) werden mit Wasser aus dem Rohprodukt herausgelöst.In der Kristallstruktur von Sm4N2S3 (monoklin, C2/m (Nr. 12), Z = 2, a = 1 318,04(12); b = 391,57(2); c = 1 031,76(9) pm; β = 130,874(6)°; R = 0,036; Rw = 0,031) liegen zwei kristallographisch unterschiedliche Sm3+ in jeweils sechsfacher Koordination der Anionen vor. Neben verzerrten Oktaedern [(Sm1)N3S3] und [(Sm2)NS5] bilden Tetraeder [(N3-)(Sm3+)4], über zwei cis-ständige Kanten zu Ketten ∞1[(Sm1)3/3(Sm2)1/1]3+ verknüpft, das strukturelle Hauptmerkmal. Nach Art einer dichtesten „Stabpackung“ gebündelt, werden letztere durch zwei kristallographisch unterschiedliche S2- zusammengehalten, die für den Ladungsausgleich und die drei-dimensionale Vernetzung sorgen.
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  • 83
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    Zeitschrift für anorganische Chemie 620 (1994), S. 2014-2019 
    ISSN: 0044-2313
    Keywords: Phosphorus nitrides ; nitrido sodalites ; synthesis ; crystal structure ; i.r. data ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nitrido Sodalites. I Synthesis, Crystal Structure, and Properties of Zn7-xH2x [P12N24]Cl2 with 0 ≤ x ≤ 3The nitrido sodalites Zn7-xH2x[P12N24]Cl2 with 0 ≤ x ≤ 3 are obtained by heterogeneous pressure-ammonolysis of P3N5 at presence of ZnCl2 (T = 650°C). These compounds are available too by reaction of ZnCl2, (PNCl2)3, and NH4Cl at 700°C. The crystal structures of four representatives of the above mentioned compounds have been refined by the Rietveld full-profile technique using X-ray powder diffractometer data (I43m, a = 821.61(4) to 824.21(1) pm, Z = 1). In the solid a three-dimensional framework of corner-sharing PN4-tetrahedra occurs (P—N: 163.6 pm, P—N—P: 125.6°, mean values) which is isosteric with the sodalite type of structure. In the center of the β-cages Cl- ions have been found, which are tetrahedrally coordinated by Zn2+ ions. The Zn2+ ions are statistically disordered. According to the phase-width observed (0 ≤ x ≤ 3) the Zn2+ ions may be partially replaced each by two hydrogen atoms which on the other hand are covalently bonded to nitrogen atoms of the P—N framework. The IR-spectra of these compounds show characteristic vibrations.
    Notes: Die Nitrido-Sodalithe Zn7-xH2x[P12N24]Cl2 mit 0 ≤ x ≤ 3 wurden durch heterogene Druckammonolyse von P3N5 in Gegenwart von ZnCl2 (T = 650°C) dargestellt. Die Verbindungen sind auch zugänglich durch Umsetzung von ZnCl2, (PNCl2)3 und NH4Cl bei 700°C. Die Kristallstrukturen von vier ausgewählten Vertretern der obigen Verbindungsreihe wurden auf der Basis von Röntgen-Pulverdiffraktometerdaten mit Hilfe der Rietveld-Methode verfeinert (I43m, a = 821,61(4) bis 824,21(1) pm, Z = 1). Im Festkörper liegt eine dreidimensionale Gerüststruktur allseitig eckenverknüpfter PN4-Tetraeder vor (P—N: 163,6 pm, P—N—P: 125,6°, Mittelwerte), die dem Sodalith-Typ entspricht. Im Zentrum der β-Käfige befinden sich Cl--Ionen, die ihrerseits tetraedrisch durch Zn2+-Ionen umgeben sind. Die Zn2+-Positionen sind statistisch besetzt und gemäß der angegebenen Phasenbreite (0 ≤ x ≤ 3) kann ein Teil der Zn2+-Ionen durch jeweils zwei H-Atome ersetzt werden, die ihrerseits kovalent an Stickstoffatome des P—N-Gerüstes gebunden sind. Im IR-Spektrum der Verbindungen werden charakteristische Schwingungsbanden beobachtet.
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  • 84
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1943-1946 
    ISSN: 0044-2313
    Keywords: Ternary chlorometalates(III) ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metal Coordination Compounds Prepared in Acetic Acid. I. Chlorometalates(III) of Iron, Chromium, and VanadiumTernary chloride-hydrates A2MCl5 · H2O (A = Cs, Rb, (K)) can be precipitated with HCl from solutions of MCl3 · 6 H2O, (M = Fe, Cr, V) and alkali metal acetates in acetic acid. Under special conditions also compounds of the composition Cs3MCl6 · H2O can be obtained. After dehydration of the solutions with acetyl chloride, anhydrous compounds are formed: Cs3Fe2Cl9; A3CrCl6 and A3Cr2Cl9 with A = Cs, Rb; Cs3VCl6 and Cs3V2Cl9. VIII is partially oxidized to VIV by an excess of acetyl chloride. Compounds A2VCl6 with A = Cs, Rb can be obtained more conveniently by the reaction of VOCl2 · H2O in acetic acid with acetyl chloride.The lattice parameters of some compounds were determined from powder patterns in analogy to known structure families.
    Notes: Aus Lösungen der Chloridhydrate MCl3 · 6 H2O (M = Fe, Cr, V) in Eisessig lassen sich nach Zugabe von Alkalimetallacetaten mit HCl ternäre Chloridhydrate A2MCl5 · H2O (A = Cs, Rb, z. T. K), unter speziellen Bedingungen auch Verbindungen der Zusammensetzung Cs3MCl6 · H2O fällen. Werden die Ausgangslösungen mit Acetylchlorid dehydratisiert, so entstehen wasserfreie Chlorometallate(III): Cs3Fe2Cl9; A3CrCl6 und A3Cr2Cl9 mit A = Cs, Rb; Cs3VCl6 und Cs3V2Cl9. Vanadium(III) kann teilweise zu VIV oxidiert werden. Chlorovanadate A2VCl6 mit A = Cs, Rb lassen sich aber günstiger aus Lösungen von VOCl2 · 2 H2O in Eisessig mit Acetylchlorid erhalten.Von einigen strukturell noch nicht untersuchten Verbindungen sind durch Analogindizierungen von Pulveraufnahmen die Gitterparameter bestimmt worden.
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  • 85
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1983-1985 
    ISSN: 0044-2313
    Keywords: Metal hydrides ; rhodium ; lithium ; crystal structure ; neutron diffraction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Structure of Li3RhH6  -  a Ternary Hydride with Isolated [RhH6]3- OctahedraThe ternary rhodium hydride Li3RhH6 was synthesized by the reaction of lithium hydride with rhodium under a hydrogen pressure of 80 bar. X-ray investigations on powdered samples and an elastic neutron diffraction experiment on the deuterated compound led to the complete structure determination (space group: Pnma, Z = 4). The atomic arrangement is isotypic to the Na3RhH6 structure type. The crystal structure contains isolated [RhH6]3- octahedra, which are separated by the lithium ions.
    Notes: Die Synthese von Li3RhH6 gelingt durch Umsetzung von Lithiumhydrid mit feinverteiltem Rhodium unter einem Wasserstoffdruck von 80 bar. Röntgenographische Untersuchungen an pulverförmigen Proben und ein elastisches Neutronenbeugungsexperiment an der deuterierten Verbindung führten zur Strukturaufklärung (Raumgruppe: Pnma, Z = 4). Die Verbindung ist isotyp zu der von Na3RhH6 und enthält isolierte [RhH6]3--Oktaeder, die durch die Lithiumionen separiert werden.
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  • 86
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1998-2002 
    ISSN: 0044-2313
    Keywords: Lanthanides ; nitride sulfide chlorides ; M4NS3Cl3 ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nitride Sulfide Chlorides of the Lanthanides. I. The Composition M4NS3Cl3 (M = La—Nd)The oxidation of the „light“ lanthanides (M = La—Nd) with sulfur and NaN3 the presence of the chlorides MCl3 results in the formation of the first lanthanide nitride sulfide chlorides M4NS3Cl3 when appropriate molar ratios of the reactants are used. The addition of some NaCl (or an excess of MCl3) as a flux secures complete and fast reaction (7 d) at 850°C in evacuated silica vessels as well as single-crystalline products. Since these nitride sulfide chlorides (fine transparent needles) are not sensitive against hydrolysis, the surplus chloride can be removed easily with water.The crystal structure was determined from X-ray single crystal data for the example of La4NS3Cl3 (hexagonal, P63mc (no. 186), Z = 2, a = 941.40(3), c = 700.36(3) pm, R = 0.026, Rw = 0.021) and the nitride sulfide chlorides M4NS3Cl3 with M = Ce—Nd proved to be isostructural from Guinier powder data. According to their Ba3OCl6-analogue structure, two crystallographically different M3+ cations are present (CN(M1) = 10, CN(M2) = 8). „Isolated“ tetrahedra [(N3-)(M3+)4] build up the Mayn structural feature according to ∞0[NM4]S3Cl3. They are hexagonally closest packed and interconnected via the crystallographically different but by X-ray diffraction indistinguishable anions S2- and Cl-, which take care for charge neutrality.
    Notes: Durch Oxidation der „leichten“ Lanthanide (M = La—Nd) mit Schwefel und NaN3 in Gegenwart der Chloride MCl3 erhält man aus Gemengen mit entsprechenden molaren Verhältnissen der Ausgangsstoffe erstmals Nitridsulfidchloride der Lanthanide: M4NS3Cl3. Geringer Zusatz von NaCl (bzw. MCl3 im Überschuß) als Flußmittel gewährleistet vollständige und schnelle Umsetzung (7 d) bei 850°C in evakuierten Quarzglasampullen sowie einkristalline Produkte. Wegen der Unempfindlichkeit dieser Nitridsulfidchloride (feine, transparente Kristallnadeln) gegenüber Hydrolyse kann überschüssiges Chlorid leicht mit Wasser entfernt werden.Die Kristallstruktur wurde anhand von röntgenographischen Einkristalldaten am Beispiel von La4NS3Cl3 (hexagonal, P63mc (Nr. 186), Z = 2; a = 941,40(3); c = 700,36(3) pm; R = 0,026; Rw = 0,021) bestimmt und die Nitridsulfidchloride M4NS3Cl3 mit M = Ce—Nd sind nach Ausweis von Guinier-Pulveraufnahmen isotyp. Demnach liegt eine Ba4OCl6-analoge Struktur vor, in der zwei kristallographisch unterschiedliche M3+-Kationen auftreten (CN(M1) = 10, CN(M2) = 8). „Isolierte“ Tetraeder [(N3-)(M3+)4] bilden gemäß ∞0[NM4]S3Cl3 das strukturelle Hauptmerkmal und sind nach Art einer hexagonal-dichtesten Kugelpackung angeordnet. Der Ladungsausgleich erfolgt über die kristallographisch unterschiedlichen, röntgenographisch jedoch nicht unterscheidbaren Anionen S2- und Cl-.
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  • 87
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 2008-2013 
    ISSN: 0044-2313
    Keywords: Barium nitrido zirconate, Ba[ZrN2] ; barium nitrido niobate, Ba2[NbN3] ; synthesis ; crystal structure ; neutron diffraction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese und Struktur von Ba[ZrN2] und Ba2[NbN3]Ba3N2 reagiert im Stickstoffstrom bei 950°C mit Zr unter Bildung von luftempfindlichem, dunkelrotem Ba[ZrN2]. Es kristallisiert tetragonal in der Raumgruppe P4/nmm mit a = 416,10(2), c = 839,2(1) pm und Z = 2. Die Kristallstruktur wurde anhand von Röntgen- und Neutronenbeugungsdaten des Kristallpulvers verfeinert. Im Nitridozirconat [ZrN2]2- ist das Zr-Atom quadratisch-pyramidal von fünf N-Atomen im Abstand von 201(3) und 220,2(2) pm koordiniert. Die Koordinationspolyeder sind in der Pyramidenbasis über alle Kanten verknüpft und bilden Schichten parallel (001) mit den Pyramidenspitzen alternierend nach oben und nach unten weisend. Die Ba2+-Kationen sind auf der Höhe der Pyramidenspitzen in diese Schichten integriert. Die Struktur kann als aufgefüllter PbFCl-Typ interpretiert werden. Ba2[NbN3] entsteht aus Ba3N2 und NbN oder aus Ba und Nb im Stickstoffstrom bei ca. 1 000°C. Es kristallisiert isotyp zu Ba2[TaN3] in der monoklinen Raumgruppe C2/c mit a = 613,2(3), b = 1 176,8(3), c = 1 322,9(4) pm, β = 91,65(2)°, Z = 8. Die Nitridoniobat-Anionen bilden Ketten aus eckenverknüpften NbN4-Tetraedern mit Abständen Nb—N zwischen 188(1) und 199,9(9) pm.
    Notes: Ba3N2 reacts at 950°C under pure N2 with Zr to yield dark red, air-sensitive Ba[ZrN2]. This new compound crystallizes in the tetragonal space group P4/nmm with a = 416.10(2), c = 839.2(1) pm and Z = 2. The crystal structure was solved and refined using X-ray and neutron powder diffraction data. In the nitrido zirconate [ZrN2]2- the Zr atoms exhibit a square-pyramidal coordination by five N atoms at distances of 201(3) and 220.2(2) pm. The pyramids share all the edges in the basal plane to form layers parallel to (001) with their apices alternately pointing up and down. The Ba2+ cations are integrated into these layers at the levels of the pyramidal apices. The structure can be interpreted as a stuffed PbFCl type. Ba2[NbN3] is formed by the reaction of Ba3N2 and NbN or of Ba and Nb at 1 000°C under N2. Isostructural to Ba2[TaN3] it crystallizes in the monoclinic space group C2/c with a = 613.2(3), b = 1 176.8(3), c = 1 322.9(4) pm, β = 91.65(2)°, Z = 8. The nitrido niobate anions form chains of corner sharing NbN4 tetrahedra with distances Nb—N between 188(1) and 199.9(9) pm.
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  • 88
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 334-342 
    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.
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  • 89
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 343-345 
    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.
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  • 90
    ISSN: 0044-2313
    Keywords: Bis(dimethylamino)boryl-tris(dimethylamino)silyl-tris(dimethylamino)titanylamin ; N,N′-Bis(tris(dimethylamino)-silyl)-1,1,3,3-tetrakis(dimethylamino)cyclobistitanazan, Trimethylsilyl-tris(dimethylamino)silyl-tris(dimethylamino)titanylamin ; Trimethylsilyl-tris(dimethylamino)-silylamin ; synthesis ; nmr spectra ; mass spectra ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N(B(NMe2)2)(Si(NMe2)3) (Ti(NMe2)3), [N(Si(NMe2)3)(Ti(NMe2)2)]2 und N(SiMe3)(Si(NMe2)3)(Ti(NMe2)3)  -  Synthesis and Characterization of New Molecular Single-source Precursors for Nitride and Carbonitride CeramicsSynthesis and spectroscopic data of the title compounds are reported. [N(Si(NMe2)3)(Ti(NMe2)2)]2 crystallizes in the space group P1, a = 8.406(7), b = 10.673(8), c = 10.872(6) Å, α = 68.45(4)°, β = 71.72(4)°, γ = 78.11(7)°, 2 877 diffractometer data (Fo ≥ 2σFo), R = 0.051. The compound is characterized by a planar four-membered Ti2N2-ring with exocyclic tris(dimethylamino)silyl substituents attached to the nitrogen atoms of the ring.
    Notes: Darstellung, kernresonanz- und massenspektroskopische Daten der Titelverbindungen werden mitgeteilt. [N(Si(NMe2)3)(Ti(NMe2)2)]2 kristallisiert in der Raumgruppe P1 mit den Gitterkonstanten a = 8,406(7), b = 10,673(8), c = 10,872(6) Å, α = 68,45(4)°, β = 71,72(4)°, γ = 78,11(7)°. 2 877 Diffraktometerdaten (Fo ≥ 2σFo), R = 0,051. Die Verbindung besitzt einen planaren Ti2N2-Vierring mit exocyclischen Tris(dimethylamino)silylsubstituenten an den Stickstoffatomen des Rings.
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  • 91
    ISSN: 0044-2313
    Keywords: Tetramethyltitanium-1,2-bis(dimethylphosphino)-ethane ; NMR data ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Transition Metal Alkyl Compounds. 61. Preparation and Crystal Structure of Tetramethyltitanium-1,2-bis(dimethylphosphino)ethaneThe title complex 1 was synthesized by addition of 1,2-bis(dimethylphosphino)ethane to a solution of tetramethyltitanium in diethylether. The complex was characterized by 1H, 13C and 31P NMR spectra and by X-ray crystal structure analysis. 1 consists of two independent molecules with distorted octahedral structure.
    Notes: Der Titelkomplex 1 wurde durch Addition von 1,2-Bis(dimethylphosphino)ethan an Tetramethyltitan in Diethylether erhalten. Der Komplex wurde 1H-, 13C- und 31P-NMR-spektroskopisch, sowie durch Röntgenkristallstruktur-analyse charakterisiert. 1 tritt in der Elementarzelle in zwei unabhängigen Molekülen mit verzerrt oktaedrischer Konstitution auf.
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  • 92
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 531-534 
    ISSN: 0044-2313
    Keywords: Cesium tetraimidophosphate-diamide ; synthesis ; 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 a Cesium-tetraimidophosphate-diamide, Cs5[P(NH)4](NH2)2 = Cs3[P(NH)4] · 2 CsNH2Well crystallized Cesium-tetraimidophosphate-diamide is obtained by the reaction of CsNH2 with P3N5 in autoclaves at 673 K within three days. X-ray single crystal investigations led to the following dataCcca, Z = 4, a = 8.192(5) Å, b = 20.472(5) Å,c = 8.252(3) ÅZ(F2o) ≥3σ(F2o) = 916, Z(Var.) = 32, R/Rw=1 = 0.017/0.021The compound contains the hitherto unknown anion [P(NH)4]3-.
    Notes: Gut kristallisiertes Caesium-tetraimidophosphat-diamid entsteht bei der Umsetzung von CsNH2 mit P3N5 in Autoklaven bei 673 K innerhalb von drei Tagen. Röntgenographische Untersuchungen an Einkristallen der Verbindung ergaben:Ccca, Z = 4, a = 8,192(5) Å, b = 20,472(5) Å,c = 8,252(3) ÅZ(F2o) ≥ 3σ(F2o) = 916, Z(Var.) = 32, R/Rw=1 = 0,017/0,021Die Verbindung enthält das bis dahin unbekannte Anion [P(NH)4]3-.
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  • 93
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 535-538 
    ISSN: 0044-2313
    Keywords: Sodium tetraoxo nitrido tungstate(VI) ; synthesis ; 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 Sodium Tetraoxo Nitrido Tungstate(VI), Na5WO4NColourless crystals of Na5WO4N are obtained besides Na4WO2N2 [1] by the reaction of WO3 with NaNH2 (15:1) at 350°C ≥ T ≥ 750°C in autoclaves to prevent early decomposition of sodium amide. X-ray single crystal investigations are characterized by the following data:Na5WO4N: Cmc21 (No. 36), Z = 4a = 9.873(2) Å, b = 5.769(1) Å, c = 10.648(2) ÅZ(F2o)≥ 3σ(F2o) = 2182, Z(Var.) = 55, R/Rw = 0.029/0.039The structure contains the tetragonal pyramidal ion WO4N5- with nitrogen at the apex connected via Na+ ions irregularly coordinated by one nitrogen and four oxygen atoms of different anions.
    Notes: Farblose Kristalle von Na5WO4N entstehen neben Na4WO2N2 [1] bei der Umsetzung von WO3 mit NaNH2 (15:1) bei 350°C ≥ T ≥ 750°C in Autoklaven, die eine frühzeitige Zersetzung von Natriumamid verhindern. Die röntgenographische Strukturbestimmung an Einkristallen ist durch folgende Daten charakterisiert:Na5WO4N: Cmc21 (Nr. 36), Z = 4a = 9,873(2) Å, b = 5,769(1) Å, c = 10,648(2) ÅZ(F2o) ≥ 3σ(F2o) = 2182, Z(Var.) = 55, R/Rw = 0,029/0,039Die Struktur enthält das tetragonal pyramidale Ion WO4N5 mit Stickstoff in apikaler Position. Die Anionen sind durch Na+-Ionen verknüpft, die unregelmäßig von einem N- und vier O-Atomen unterschiedlicher Anionen koordiniert sind.
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  • 94
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 527-530 
    ISSN: 0044-2313
    Keywords: Barium ; rare earth ; zinc ; oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Crystal Chemistry of a New Barium Rare-Earth Oxozincate: Ba2Er2Zn8O13High temperature reactions led to single crystals of Ba2Er2Zn8O13. It crystallizes with orthorhombic symmetry, space group C122v—Cmc21, a = 6.276, b = 10.871, c = 10.195 Å, Z = 2. The hitherto unknown crystal structure shows Zn2+ with tetrahedral, Er3+ octahedral and Ba2+ cuboctahedral coordination by O2-. It will be shown that parts of the [Zn8O13] network are fragments of the ZnO structure showing O2- within a tetrahedral zinc coordination. A deficit of two O2- ions per unit cell is focused on two point positions.
    Notes: Durch Hochtemperaturreaktionen wurden Einkristalle von Ba2Er2Zn8O13 dargestellt und anschließend röntgenographisch untersucht. Die Verbindung kristallisiert in einem neuen Strukturtyp mit orthorhombischer Symmetrie, Raumgruppe C122v—Cmc21; a = 6,276; b = 10,871; c = 10,195 Å; Z = 2. Die bisher unbekannte Kristallstruktur zeigt Zn2+ in tetraedrischer, Er3+ in oktaedrischer und Ba2+ in kuboktaedrischer Koordination von O2-. Es wird gezeigt, daß das [Zn8O13]-Gerüst Fragmente der ZnO-Struktur mit O2- in tetraedrischer Zinkkoordination enthält. Ein Defizit von zwei O2 pro Elementarzelle verteilt sich auf zwei Punktlagen.
    Additional Material: 3 Ill.
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  • 95
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 545-550 
    ISSN: 0044-2313
    Keywords: Dipotassium tetramanganese cyclodecaphosphate octadecahydrate ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung und Kristallstruktur von Kaliummangancyclodecaphosphat-octadecahydrat: K2Mn4P10O30 · 18 H2ODie Titelverbindung, ein neues Cyclodecaphosphat, wurde durch Fällung aus wäßriger K10P10O30-Lösung hergestellt. Das in Wasser wenig lösliche Salz kristalliert monoklin in der Raumgruppe P21/a mit den Gitterkonstanten a = 14,546(10), b = 15,211(10), c = 9,860(6) Å, β = 105,12(4)°.Die Kristallstruktur wurde unter Verwendung von 6501 unabhängigen Reflexen gelöst, der R-Wert beträgt 0,044.Die zentrosymmetrischen Ringanionen sind relativ weit voneinander entfernt und in einer pseudotetragonalen Weise angeordnet, so daß parallel zur c-Achse große, die Wassermoleküle enthaltende Kanäle gebildet werden.
    Notes: The title compound, a new cyclodecaphosphate, was prepared by precipitation from an aqueous solution of K10P10O30. The sparingly soluble salt crystallizes monoclinic in the space group P21/a, with Z = 2, and the unit-cell dimensions a = 14.546(10), b = 15.211(10), c = 9.860(6) Å, β = 105.12(4)°.The crystal structure was solved using 6501 unique reflections with a final R-value of 0.044.The centrosymmetrical ring anions rather distant from each other and arranged in a pseudo-tetragonal way create, parallel to the c direction, large channels containing the water molecules.
    Additional Material: 3 Ill.
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  • 96
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 561-565 
    ISSN: 0044-2313
    Keywords: Ternary palladium phosphide ; erbium ; crystal structure ; band calculations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Er3Pd7P4  -  Crystal Structure Determination and Extended Hückel CalculationsEr3Pd7P4 was prepared by heating the elements (1050°C) and investigated by means of single-crystal X-ray methods. The compound crystallizes in a new structure (C2/m; a = 15.180(3) Å, b = 3.955(1) Å, c = 9.320(1) Å, β = 125,65(1)°; Z = 2) with a three-dimensional framework of Pd and P atoms and with Er atoms in the holes. The Pd atoms are surrounded tetrahedrally, trigonally or linearly by P atoms, which are coordinated by nine metal atoms in the form of a tricapped trigonal prism. Therefore the atomic arrangement of Er3Pd7P4 is related to the structures of ternary transition metal phosphides with a metal: phosphorus ratio of 2:1. Band calculations using the Extended Hückel method show strong covalent Pd—P bonds and weak bonding interactions between Pd atoms with Pd—Pd distances shorter than 2.9 Å.
    Notes: Er3Pd7P4 wurde durch Erhitzen der Elemente auf 1050°C dargestellt und röntgenographisch mit Einkristallmethoden untersucht. Die Verbindung kristallisiert monoklin (C2/m; a = 15,180(3) Å, b = 3,955(1) Å, c = 9,320(1) Å, β = 125,65(1)°; Z = 2) in einer neuen Struktur mit einem dreidimensionalen Gerüst aus Pd- und P-Atomen, in dessen Lücken sich die Er-Atome befinden. Die P-Umgebung der Pd-Atome ist tetraedrisch, trigonal oder linear. Die P-Atome ihrerseits werden von 9 Metallatomen in Form eines dreifach überkappten trigonalen Prismas koordiniert. Der Aufbau von Er3Pd7P4 ist dementsprechend verwandt mit den Strukturen ternärer Übergangsmetall-Phosphide mit einem Metall: Nichtmetallverhältnis von 2:1. Extended Hückel Rechnungen zeigen u. a. neben starken kovalenten Pd—P-Bindungen schwache bindende Wechselwirkungen zwischen denjenigen Pd-Atomen, deren Abstände voneinander kürzer als 2,9 Å sind.
    Additional Material: 5 Ill.
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  • 97
    ISSN: 0044-2313
    Keywords: Tris[(O,O′)-diorganodithiophosphato]phenyltellurium(IV) compounds (O,O′)-Diorganodithiophosphatophenyltellurium(II) compounds ; reductive elimination ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (O,O′)-Diorganodithiophosphatophenyltellurium(II)- and Tris[(O,O′)-diorganodithiophosphato]phenyltellurium(IV) Compounds; Crystal Structure of Tris[(O,O′)-diphenyldithiophosphato]phenyltellur(IV)The title compounds are available by reaction of trichlorophenyltellurium(IV) respectively iodophenyltellurium(II) with the sodium or ammonium salts of (O,O′)-diorganodithiophosphorus acids in various solvents. The resulting tellurium(IV) compounds have a pronounced tendency towards reductive elimination of bis[(O,O′)-diorganothiophosphoryl]disulfanes [S2P(OR)2]2 in solution. In contrast, the tellurium(II) compounds are stable, although they are disintegrated to diphenylditellane and [S2P(OR)2]2 on prolonged standing in chlorinated hydrocarbons.Crystals of tris[(O,O′)-diphenyldithiophosphato]phenyltellurium(IV) are monoclinic (space group P21/c) with the cell constants: a = 1 039.2(1), b = 1 037.9(3), c = 4 205.0(1) pm, β = 95.273(1)°, V = 4 516.42(9)X106 pm3, Z = 4. The compound appears to be monomeric in the solid state forming a distorted pentagonal bipyramid. The stereochemical influence of the lone pair of electrons causes the axial (i. e. C1—Te—S4) angle to be 156.6(1)° rather than the theoretical 180°.
    Notes: Die Titelverbindungen sind durch Reaktion von Trichlorophenyltellur(IV) bzw. Iodophenyltellur(II) mit Natrium- oder Ammoniumsalzen von (O,O′)-Diorganodithiophosphorsäuren in verschiedenen Lösungsmitteln zugänglich. Die dabei erhaltenen Tellur(IV)-Verbindungen zeigen in Lösung eine ausgeprägte Tendenz zur reduktiven Eliminierung der Bis[(O,O′)-diorganothiophosphoryl]disulfane [S2P(OR)2]2. Die Tellur(II)-Verbindungen sind dagegen stabil, zersetzen sich aber bei längerem Stehenlassen in chlorierten Kohlenwasserstoffen in Diphenylditellan und [S2P(OR)2]2.Die Kristalle von Tris[(O,O′)-diphenyldithiophosphato]phenyltellur(IV) sind monoklin (Raumgruppe P21/c) mit den Zellkonstanten a = 1 039,2(1), b = 1 037,9(3), c = 4 205,0(1) pm, β = 95,273(1)°, V = 4 516,42(9)X106 pm3, Z = 4. Die Verbindung liegt im Kristall monomer in Form einer verzerrt pentagonalen Bipyramide vor. Das stereochemisch aktive freie Elektronenpaar bedingt einen von den theoretischen 180° abweichenden axialen (d. h. C1—Te—S4) Winkel von 156,6(1)°.
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  • 98
    ISSN: 0044-2313
    Keywords: Selenium complexes ; tellurium complexes ; dicyanethylenedithiolate ; dicyanethylenethioselenolate ; dicyanethylenediselenolate ; syntheses ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structures of New SeII and TeII Complexes Containing 2,2-Dicyanethylene-1,1-dithiolate, 2,2-Dicyanethylene-1,1-thioselenolate, and 2,2-Dicyanethylene-1,1-diselenolate(NBu4)2{Se[S2C=C(CN)2]2} (I), (AsPh4)2 · {Te[SSeC=C(CN)2]2} (II), and (NBu4)2{Te[Se2C=C(CN)2]2} (III) containing the bidentate chelate ligands 2,2-dicyanethylene-1,1-dithiolate i-mnt, 2,2-dicyanethylene-1,1-thioselenolate i-mnts, and 2,2-dicyanethylene-1,1-diselenolate i-mns have been prepared and characterized by X-ray structure analysis. The central units consist of [M(X—X)2E2]2- (M = Se, Te; X—X = ligand; E = lone-pair) with fourfold coordinated SeII and TeII, respectively. The complex anions [Se(i-mnt)2E2]2- as well as [Te(i-mnts)2E2]2- show a trapezoide distortion with d(Se—S) = 2.276(5); 2.287(5); 2.803(5); 2.789(5) Å and d(Te—Se) = 2.611(2); 2.617(3); d(Te—S) = 2.889(5); 2.935(4) Å. In III there are centrosymmetric complex anions [Te(i-mns)2E2]2- with nearly identical Te—Se-bond-lengths: 2.674(3) and 2.692(2) Å. These Te—Se bonds are elongated compared to usual Te—Se bonds.
    Notes: (NBu4)2{Se[S2C=C(CN)2]2} (I), (AsPh4)2 · {Te[SSeC=C(CN)2]2} (II) und (NBu4)2{Te[Se2C=C(CN)2]2} (III) mit den zweizähnigen Liganden 2,2-Dicyanethylen-1,1-dithiolat i-mnt, 2,2-Dicyanethylen-1,1-thioselenolat i-mnts und 2,2-Dicyanethylen-1,1-diselenolat i-mns wurden dargestellt und durch Einkristallstrukturanalysen charakterisiert. In den zentralen M(X—X)2E2-Einheiten (M = Se, Te; X—X = Ligand, E = freies Elektronenpaar) liegt vierfach koordiniertes SeII bzw. TeII vor. Die Komplexanionen [Se(i-mnt)2E2]2- und [Te(i-mnts)2E2]2- sind trapezförmig verzerrt mit d(Se—S) = 2,276(5); 2,287(5); 2,803(5); 2,789(5) Å und d(Te—Se) = 2,611(2); 2,617(3); d(Te—S) = 2,889(5); 2,935(4) Å. In III liegen dagegen zentrosymmetrische Komplexanionen [Te(i-mns)2E2]2- mit nahezu gleichlangen Te—Se-Bindungen vor: 2,674(3) und 2,692(2) Å. Die Te—Se-Bindungen sind dabei gegenüber gewöhnlichen Te—Se-Bindungslängen deutlich aufgeweitet.
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  • 99
    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.
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  • 100
    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)
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