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  • 1995-1999  (2,607)
  • 1890-1899  (8,112)
  • Inorganic Chemistry  (9,889)
  • Atomic, Molecular and Optical Physics  (830)
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  • 201
    Electronic Resource
    Electronic Resource
    Preparation, Properties, and Reactions, of Metal-Containing Heterocycles, XCVIPart XCV: E. Lindner, E. Bosch, R. Fawzi, M. Steimann, H.A. Mayer, K. Gierling, Chem. Ber. 1996, 129, 945-951.. Mono-, Di- and Trinuclear Metallacycloalkanes of the Iron-TriadDedicated to Professor Wolfgang Beck on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 347-356 
    Details
    ISSN: 0009-2940
    Keywords: Metallacycloalkanes ; Metallacycloalkenes ; Osmium ; Iron ; Cyclic ketones ; Metallacycles ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of the bis(triflates) [F3CSO3-(CH)m-O3SCF3] [m = 5-10, 12, 14, 16 (1a-i) with Na2[Os(CO)4] in dimethyl either affords the osmacycloalkanes 2a, 2b and 2f-i (m = 5, 6, 10, 12, 14, 16), diosmacycloalkanes 3a-i (m = 5-10, 12, 14, 16), and triosmacycloalkanes 4a-i (m = 5-10, 12, 14, 16). The structure of 3f was investigated by an X-ray structural analysis. This 22-membered disomacycle crystallizes in the space group Pā with Z = 1. If the unsaturated cis-4-octen-1,8-diyl bis(trifluoromethanesulfonate) (5) is treated with Na2[Os(CO)4] the diosmacyclooctadeca-5,14-diene 6 is obtained. By treating the bis(triflates) 1a, b with Na2[Fe(CO)4] the corresponding ferracycloalkanes are formed only in situ. Insertion of carbon monoxide into the M-C σ bonds leads to the cyclic ketones 7a, d and to the diketone 8d.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300308
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  • 202
    Electronic Resource
    Electronic Resource
    Enantioselective Catalysis, XIIIPart XII: U. Nagel, J. Leipold, Chem. Ber., 1996, 129815-821.. Preparative and Structural Chemistry of Chiral 3-(Diphenylphosphanyl)-pyrrolidiens and Their Palladium(II) Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 385-398 
    Details
    ISSN: 0009-2940
    Keywords: Pyrrolidinephosphanes ; 3-Hydroxypyrrolidine ; 3-Diphenylphosphanylpyronlidine ; Salt effects ; Polymorphism ; Homogeneous catalysis ; Palladium ; Asymmetric catalysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation of both enantiomers of 3-diphenylphosphanulpyrrolidiine (2) and several N-substituted derivatives together with two PdIi complexes of this ligand is reported. Form L-malic acid and L-hydroxyproline both enantiomers of 3-hydroxypyrrolidine are prepared without any problems due to epimerization. KPPh2 in the presence of LiCl is shown to be the most effective reagent for the synthesis of 2. The reported X-ray structure determination sof Pdl2 complexes show a rather rigid bicyclic hetero-norbornane skeleton. The flexibility of the other parts of the molecules is obvious in several polymorphs revealed by this method. This polymorphism is additionally investigated by a 31P-CP-MAS study. From solution 1-, 13C- and 31P-NMR studies it is concluded that the bicyclic hetero-norbornane skeleton is retained in solution.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300313
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  • 203
    Electronic Resource
    Electronic Resource
    Reactions of Silicon-Silicon Bonds, VIFor part V, see ref.[1].. Reductive Trichloroslilylation Reactions Leading to Alkyl- and Dialkylaminobis(trichlorosilyl)phosphanesDedicated to Professor Walter Siebert on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 377-384 
    Details
    ISSN: 0009-2940
    Keywords: Trichlorosilylation ; Dichlorophosphanes ; Silylphosphanes ; Amino(silyl)phosphanes ; Silicon /Reductions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of hexachlorodisilane and of trichlorosilane/triethylamine with alkyl-and dialkylaminodichlorophosphanes RPCl2 1a-i [R = iPr: a; (Me3Si)2CH: b; R=1-adamantly: c: R=tBu: d; R=Et2N: e; R=iPr2M: f] furnish bis(trichlorosilyl)-phosphanes RP(SiCl3)2 3a-f. However, when less bulky substituents are attached to the phosphorus atom, so that there is little steric crowding, the double reductive silylations leading from 1 to 3 are accompanied by side reactions and decomposition of 3. Therefore, only 3b, 3c, 3d, and 3f wre isolated in a pure state. These compounds are more readily prepared by the; trichlorosilane/triethylamine method. 1H-, 31P- and 29Si-Nmr spectra confirm their constitution. The structure of solid 3f, the first aminobis(trichlorosilyl)phosphane, was determined by X-ray crystallography. 3f contains a phosphorus atom in a pyramidal environment surrounded by two silicon atoms and a planar nitrogen atom of the diisopropylamino group.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300312
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  • 204
    Electronic Resource
    Electronic Resource
    Formation of the Digallium Compound [(C5C6)2N3](R)Ga-Ga(R)[N3(C6H5)2] with Two Bis(trimethylsilyl)methyl Groups and Two Terminal Chelating Diphenyltriazenido Ligands (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 417-420 
    Details
    ISSN: 0009-2940
    Keywords: Gallium ; Low-valent compounds ; Gallium-gallium bond ; Terminal triphenytriazenido ligand ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tetrakis[bis(trimethylsilyl)methyl]digallane (4) 1 reacts with 1,3-diphenyltriazene to yield two compounds, which were both characterized by a crystal structure determination. The gallium-gallium bond is retained in the yellow derivate [(H5C6)2N3](R)Ga-Ga(R)[N3(C6H5)2 2 [R = CH(SiMe3)2], which is formed by a ligand exchange reaction and shows two terminal chelating triazenido ligands besides two bis(trimethylsilyl)methyl groups; the Ga—Ga bond length is 245.79(6) pm. The second product is the orange dialkyl(diphenyltriazenido)gallium derivative R2Ga[N3(C6H5)2] 3, where the triazene has reacted as an oxidant by the cleavage of the Ga—Ga bond and probably by release of elemental hydrogen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300317
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  • 205
    Electronic Resource
    Electronic Resource
    The Electronic Structure of [Te15Br4][MoOBr4]2 and Some General Aspects of Bonding in “Classical” and Hypervalent Tellurium Halides (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 463-472 
    Details
    ISSN: 0009-2940
    Keywords: Hypervalent compounds ; Tellurium ; Polycations ; Molecular Orbital Theory ; Band structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Approximate MO and band structure calculation are used to analyze the bonding in the recently synthesized paramagnetic, semiconducting phase [Te15Br4]2+. The [Te15Br4]2+ chains are very similar to those in the tellurium subhalide Te2Br. The electronic structure and bonding within these chains is analysed and the possibility of hypervalency in both [Te15Br4][MoOBr4]2 and Te2Br is discussed. The bonding in the classically hypervalent molecule TeBr42- and a model Te3Br24- is compared to that of the infinite system. Our calculations indicate that both [Te15Br4][MoOBr4]2 and Te2Br contain weakly hypervalent Te atoms and that the interesting electronic properties of [Te15Br4][MoOBr4]2 arise within the distinct sublattices, which do not interact significantly.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300405
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  • 206
    Electronic Resource
    Electronic Resource
    Inter- and Intramolecular Thermal Activation of Aliphatic C-H Bonds Mediated by Complexes Containing the Fragments [{Cy2P(CH2)nPCy2}M] (n=1-4, M = Rh, Ru) (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 555-558 
    Details
    ISSN: 0009-2940
    Keywords: C-H activation ; Homogeneous catalysis ; Dehydrogenation ; Phosphane complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A well defined geometrical structure and a well established catalytic potential for a plethora of processes puts the chelate rings [{R2P〈(CH2)nPR2}M] (M = Rh, Ru) among the most interesting candidates for catalytic alkane functionalization in homogeneous solution. It is demonstrated that intermolecular thermal C-H activation (3→4) is possible with readily accessible complexes [{Cy2P(CH2)nPCy2}Rh(hfacac)] (n = 1-4, 1a-c and [Cy2P(CH2)nPCy2}Ru(η3-C4H7)2] (n = 1-3, 2a-c) containing such fragments. A maximum of 5 catalytic cycles was achieved with complex 2a. In case of Ru complexes containing the same ligands with n =3 and 4, intramolecular cleavage of three adjacent C-H bonds in one of the cyclohexyl substituents at phosphorus also occurs readily leading to formation of a new polydentate k2P,P', η3-allyl ligand.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300504
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  • 207
    Electronic Resource
    Electronic Resource
    Synthesis and Bonding in Hybrid Diborolyl/Boranyl and Thiaboranyl Triple-Decker Compounds - Electronic Contribution of Heteroborane Cluster Ligands in ComplexesDedicated to Professor Rolf Gleiter on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 329-334 
    Details
    ISSN: 0009-2940
    Keywords: Triple-decker complexes ; Cobalta-nido-decaborane ; Thiacobalta-closo-undecaborane ; Dithiacobalta-arachno-nonaborane ; Dithiacobalta-arachno-dodecaborane ; Boron ; Cobalt/ Sandwich complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The three-component reaction of [(η5-C5H5)Co(η5-(CEt)2(BEt)2CMe)]-, CoCl2 and B9H-14 (7) yields the triple-decker complex [(η5-C5H5)Co{μ,η5-(CEt)2(BEt)2CMe}-6-Co(B9H13)] (8) with a terminal B9H13 ligand contaning two cobalt-boron-bridging hydrogen atoms. Analogously, (6-H)-, CoCl2, and arachno-6-SB9H-12 (10) react to give the triple-decker [(η5-C5H5)Co{μ,η5-(CEt)2(BEt)2CMe}-1-Co-2-(SB9H9)] (11). The analogous reaction with the heteroboranyl anion arachno-6,8-S2B7H8- leads to the loss of one boron atom, forming the air-stable triple-decker complex [(η5- C5H5)Co{μ,η5-(CEt)2(BEt)2CMe}-7-Co-6,8-(S2B6H8)] (12). The X-ray structure determination shows that the dithiacobaltaborane fragment in 12 has an arachno cluster geometry. The three-component reaction of (6-H, CoCl2, and arachno-2,3-S2B9H10- yields the expected triple-decker [(η5-C5H5)Co{μ,η5-(CEt)2(BEt)CMe}Co-6,8-(S2B9H9)] (15), and surprisingly the sandwich complex (η5-C5H5)Co-6,8-(S2B9H9) (16). The constitutions of the new compounds are based on NMR and MS data. A rule is described regarding the electron donation of heteroboranyl cluster ligands in metal complexes.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300305
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  • 208
    Electronic Resource
    Electronic Resource
    Self-Assembly of Copper(I) Halide Networks Containing Tetra- or Pentameric Ethylcycloarsoxane (C2H5AsO)n (m = 4,5) as a flexible Bridging Unit (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 371-376 
    Details
    ISSN: 0009-2940
    Keywords: Ethylcycloarsoxane ; Copper(I) halide complexes ; Layered structures ; Macrocyclic ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In complexes of ethylcycloarsoxane (C2H3AsO)n, the oligomer size n is influenced by the coordinated metal atom. Cyclic tetramers are observed in the porous sheet structures of ∞2[Cu2Br2{cyclo-(C2H5AsO)4}3] (1) and 2∞ [Cu3I3{cyclo-(C2H5As0)4)2] (2), prepared by the reaction of the appropriate copper(I) halide with (C2H5AsO)n in acetonitrile. Both complexes contain μ1κAs1:2κAs3-coordinated (C2H5AsO)4 ligands as molecular bridging units between individual copper(I) centres leading to large respectively 36- and 40-membered rings. An analogous bridging mode is found in the cyclic oligomers [cyclo-(ReBr(CO)3{μ-[cyclo-(C2H5AsO)}}4](3) formed by reacting {ReBr(CO)5] with (C2H5AsO)n in refluxing toluene. - In contrast both [(NH4){cyclo- (C2H5AsO)5}2][Ag(SCN)]2 (4) and 2∞[(Cs(cyclo-(C2H5-AsO)3]2} Cu2(μ-I)I2] (5) contain pentamers (C2H5AsO)5, which coordinate the NH+4 and Cs+ cations κ5O in a pentagonal antiprismatic fashion. In 5, prepared by self-assembly from CsI, CuI, and (C2H5AsO)n in acetonitrile, [Cs[cyclo-{C2H5AsO}5)2]+ sandwich cations are linked thorough μ-1κAs1:2κAs2-coordinated [Cu2l3]- units into polymeric chains. This coordination pattern reflects the unique ring size adaptability of the ambidentate (C2J5AsO)n ligand.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300311
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  • 209
    Electronic Resource
    Electronic Resource
    Metallacyclodisiladiazanes of Titanium and zirconium; Synthesis, Structure and Polymerization Studies (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 399-404 
    Details
    ISSN: 0009-2940
    Keywords: Disilylamides ; Group 4 Complexes ; Polymerization ; Metallacycles ; Titanium ; Zirconium ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of metallacyclodisiladiazanes has been prepared. Lithiated (SiMe2NHtBu)2 (1) reacts with TiCl4 · 2 THF to give (SiMe2NtBu)2TiCl (4). Methylation or fluorination of 4 leads to (SiMe2NtBu)2TiMe2 (8) and (SiMe2MtBu)2TiF2 (9), respectively. The reaction of ZrCl4 · 2 THF with lithiated 1 or [SiMe2NH(4-FC6J4)]2 (2) yields (SiMe2NtBu)2ZrCl2 (5) and [SiMe2N(4-FC6H4)]ZrCl2 · THF (7), respectively. The lithiated ligand [SiMe2NH(2,6-iPr2C6H3)]2 (3) reacts with noncoordinated ZrCl4 to give [SiMe2N(2,6-iPr2C6H3)]2ZrCl2 (6). X-ray structural analysis of 9 showed it to be a fluorine-bridged dimer in the solid state. Compounds 4, 6, 8 and 9 were found to be catalysts for the polymerization of ethylene.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300314
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  • 210
    Electronic Resource
    Electronic Resource
    The Biological and Medicinal Chemistry of Bismuth (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 669-681 
    Details
    ISSN: 0009-2940
    Keywords: Bismuth ; Metallodrugs ; Bioinorganic chemistry ; Chelates ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bismuth compounds have been widely used in medicine for more than 200 years, and new bismuth-containing drugs are now being developed. However the biological chemistry of bismuth is poorly understood. We review here methods for the study of bismuth compounds, and use of Bi(III) in antiulcer, antibacterial, anti-HIV and radiotherapeutic agents is described. The chemistry of Bi(III) carboxylates and aminocarboxylates is dominated by intermolecular interactions which lead to polymeric structures. Bi(III) exhibits a highly variable coordination number and coordination geometry, and alkoxide ligands can induce a strong stereochemical “lone-pair effect”. Bi(III) can bind to both Zn(II) sites (e.g. metallothionein) and Fe(III) sites (e.g. transferrin) in proteins. Further work is needed to understand the relationship between the structures and dynamics of bismuth compounds and their bioactivity.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300602
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  • 211
    Electronic Resource
    Electronic Resource
    N2Hx Coordination at the Tripod-Cobalt Template CH3C(CH2PPh2)3Co: the Transformation of η2-HNNMe2 into η1-NNMe2Ligands (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 489-492 
    Details
    ISSN: 0009-2940
    Keywords: Nitrogenases ; Tripodal ligans ; Hydrazido ligands ; Side-on - end-on coordination ; Coordination modes ; Cobalt ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: While η2-coordination of N2H4 and N2H3- to tripod-cobalt entities has been reported, stabilization of N2H2 in this system has not yet been achieved. It is observed that [tripodCo(η2-HNNMe2)]+ (3) is transformed into [tripodCo(η1-NNMe2)]+ (4) by reaction with LiN(TMS)2 as a base. The deprotonation of 3 is accompanied by a redox reaction, and the overall reaction corresponds to the transformation of 3 to 4 with the loss of an electron and a proton. The observed coupling of deprotonation and oxidation is just the reverse of the processes assumed to occur during nitrogen fixation. The results are established by the usual analytical and spectroscopic techniques as well as by X-ray analyses.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300408
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  • 212
    Electronic Resource
    Electronic Resource
    Reactions of Complex Ligands, LXXIIPart LXXI: Ref. [1].Intermolecular Pauson-Khand Reactions of Ethyl 2-Phenylethynylcyclopropanecarboxylates and [Amino(trans-2-phenylethynylcyclopropyl)methylidene]pentacarbonylchromium(0)Dedicated to Professor Dr. G. E. Herberich on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 507-514 
    Details
    ISSN: 0009-2940
    Keywords: Carbene complexes ; Chromium ; Cycloadditions ; Cyclopropanecarboxylic and derivatives ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The intermolecular Pauson-Khand reactions of ethyl trans-2-phenylethynylcyclopropanecarboxylate (1t) and [amino-(trans-2-phenylethynylcyclopropyt)methylidene]pentacarbonylchromium (9) with norbornane lead to ester and metal carbene functionalized exo-tricyclodecenones 3b-6 and 13-16, respectively, in moderate to high yields. The incorporation of the alkyne is moderately regioselective but less diastereoselective. Pairs of diastereomers are isolated after column chromatography, which can subsequently be separated by recrystallization. The minor diastereomer 3 and the major diastereomer 15 are characterized by X-ray structure analysis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300410
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  • 213
    Electronic Resource
    Electronic Resource
    Masthead (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300501
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  • 214
    Electronic Resource
    Electronic Resource
    Synthesis and Photophysical Properties of New 2,2′-Bipyridine-Bridged Bis[ruthenium(II)tris-2,2′-bipyridine] Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 529-534 
    Details
    ISSN: 0009-2940
    Keywords: Ruthenium ; 2,2′-Bipyridines ; Redox chemistry ; Fluorescence spectroscopy ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We have synthesized a new type of tris-2,2'-bipyridine ligand with 4,4'- and 6,6'-disubstituted 2,2'-bipyridine (bpy) units. The terminal 4,4'-and 6,6'-disubstituted 2,2'-bipyridine moieties are selectively coordinated by Ru(bpy)2 (bpy = 2,2′-bipyridine), whereas the central 2,2′-bipyridine ligand does not participate in any metal ion coordination. The two Ru(bpy)3 units of 7 and 8 do not interact appreciably, as is evident from their electrochemical and photophysical data. The lifetime of the excited state of compound 7 at 77 K is similar to that of Ru(bpy)2(4,4′-dimethyl-2,2′-bipyridine), whereas that of compound 8 under the same conditions is comparatively long.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300413
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  • 215
    Electronic Resource
    Electronic Resource
    Halfsandwich-Type Triisopropylstibane Ruthenium Complexes with 16-, 17-, and 18-Electron Configurations and an Unsymmetrical Binuclear 18/16-Electron Ru2(SbiPr3) SpeciesDedicated to Professor Cornelius G,. Kreiter on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 559-563 
    Details
    ISSN: 0009-2940
    Keywords: Ruthenium ; Stibane ligands ; Binuclear ruthenium complex, unsymmetrical ; Ruthenacycloentadiene ; Metallacycles ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The paramagnetic ruthenium complex [(η5-C5Me5)RuCl2-{SbiPr3}] (2), which is prepared from [(η5-C5Me5)RuCl2]n (1) and SbiPr3, reacts with Mg/Hg in THF to give the coordinatively unsaturated 16-electron species (η5-C5Me5)RuCl)(SbiPr3)] (3). Compound 3 is obtained in much better yield from [(η5-C5Me5)Ru(μ3-Cl)]4 (4) and SbiPr3 (molar ration 1:4). While 3 reacts with CO to give the 18-electron complex [(η5-C5Me5)RuCl(CO)(SbiPr3)] (5), on treatment of 3 with HCˇO2Me the metallacycle [(η5-C5Me5)RuCl{k2(C,C)-C(CO2Me}=CHC(CO2Me)=CH}(SbiPr3)] (6) is obtained. The reaction of 4 with SbiPr3 in the molar ratio of 1:2 affords the binuclear compound [(η5-C5Me5)(SbiPr3)Ru(μ-Cl)2Ru(-C5Me5)] (7). The molecular structures of 2 and 7 have been determined by X-ray crystallography.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300505
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  • 216
    Electronic Resource
    Electronic Resource
    Transition Metal Complexes with Sulfur Ligands, 123[Part 122: D. Sellmann, S. Emig, F. Heinemann, F. Knoch, Angew. Chem. submitted.[ Synthesis and Reactivity of New Complexes Containing the [Ru(“S4”)] Fragment [S42- = 1,2-Bis(2-mercaptophenylthio)ethane(2-)] (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 571-579 
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    ISSN: 0009-2940
    Keywords: Labile ruthenium-sulfur complexes ; S2 Complexes ; Substitution reactions ; Ligand effects ; Structure-activity relationships ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to synthesize labile and well-soluble [Ru(L)(L')(“S4”)] complexes, [Ru(CI)2(DMSO)4] was treated With “S4”-Na2 (S42- = 1,2-bis(2-mercaptophenylthio)-ethane(2-1)] yielding [Ru(DMSO)2(“S4”)] (1 which contains two labile DMSO ligands. An X-ray structural analysis of 1, verifies that both DMSO ligands are coordinated via their S atoms. The reaction of 1 with small ligands such as PR3 (R = Et, nPr, nBu) or tetrahydrothiophene (THT) leads to substitution of both DMSO ligands yielding [Ru(PR3)2(“S4”)] (R = Et 3a, nPr 3b, nBu 3c) and [Ru(THT)2(“S4”] 2, respectively, while bulky phosphane ligands such as PCy3 and PiPr3 substitute one DMSO ligand to yield [Ru(DMSO)(PR3])(“S4”] (R = iPr 4a, Cy 4b). X-ray structural analyses of [Ru(PnPr3)2(“S4”)] · 0.5 MeOH (3b · 0.5 MeOH), [Ru(PnBu3)2(S4)} (3c), and [Ru(Pme3)2(“S4”)] (3d) confirm the pseudo-octahedral coordination of the Ru centers by four Sdonors and two cis P-donors and reveal close similarities bet ween the three complexes. Comparision of the structural parameters of 3b · 0.5 MeOH, 3c and 3d with those of [Ru(PPh3)2(“MeS, 4”)] [MeS4“2” = 1,2-bis(2-mercaptophenylthio)propane(2-1)] indicates that the inertness towards substitution of 3b · 0.5 MeOH, 3c and 3d as opposed to the substitution lability of [Ru(PPh3)2(,MeS4“)] is caused by the small cone angles of the alkyl phosphanes. In the DMSO/PCy3 complex 4b both coligands are labile, and which one is substituted depends on the size of the entering ligand. The reactions of 4b with PnR3 yield [Ru(DMSO)(PR3)('S4”)] (R = nPr 4c, nBu 4d) in contrast to the reaction with CO. PMe3, and SMe2 which give [Ru(CO)(Pcy3)(“S4”)] (5b), [Ru(P-Me3)(PCy3)(“S4”)] (6, and [Ru(SMe2)(PCy3)(“S4”)] (7, respectively. In an analogous manner, the CO complexes [Ru(CO(PR3)(“S4”)] (R = iPr 5a, nBu 5c) have been obtained by treatement of 4a and 4d with CO. The reactions of 4a and 4b with S8 yielded the readily soluble μ-S2 complexes [μ-S2[Ru(PR3)(“S4”)]2] (R - iPr 8a, Cy 8b). The spectroscopi9c data of complex 8b and its cyclic voltammogram, which exhibits four quasi-reversible redox waves, indicate a strong electronic coupling of the two [Ru(PCy3)(“S4”)] fragments via the μ-S2 bridge.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300507
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  • 217
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    Dynamic Behavior of Anionic Binuclear Helicate- and meso-Helicate-Type Coordination Compounds (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 615-619 
    Details
    ISSN: 0009-2940
    Keywords: Self-assembly ; NMR spectroscopy ; Titanium ; Catechol ligands ; Helical structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The racemization/symmetrization of helicate- or meso-helicate-type dinuclear titanium(IV) complexes Mn[(ligand)3Ti2] (n = 4: M = Li, Na, K, Cs; n = 2: M = Ca, Sr), which are formed by metal-directed self-assembly of alkyl-bridged bis(catecholate) ligands in the presence of basic alkali-metal or alkaline-earth metal salts, can be monitored by dynamic NMR spectroscopy. The free-energy barrier (ΔG
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300512
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  • 218
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    Thio-Ligation to Vanadium: The NSSN and S′N′O Donor Sets (N = Pyridine, N′ = Enamine; S = Thioether, S′ = Thiolate) (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1129-1133 
    Details
    ISSN: 0009-2940
    Keywords: Vanadium ; S Ligands ; Schiff bases ; N ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The tetradentate, neutral disulfide [bis(thioether)] ligand 1,6-bis(o-pyridyl)-2,4-dithiahexane, NSSN, reacts with [VCI2(tmeda)2] to form the octahedral (all-cis; C2v-symmetric) complex [VCl2(NSSN)] 1, the first low-valent vanadium complex in which the thio functions are exclusively organic sulfides. Treatment of (VOCl2(thf)2] with O-mercaptoaniline, followed by reaction with o-hydroxynaphthaldehyde yields the non-oxo V′” complex [V(S′N′O)2] 2, derived from the Schiff base HS′N′OH, where 0 and S′ are phenolate and thiophenolate functions, respectively, and N′ is the Schiff base (enamine) nitrogen. Complex 2, with the ligands in a distorted trigonal-antiprismatic array, is a rare example of a structurally characterized complex where the Schiff base is preserved at the expense of its thiazoline tautomeric form.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300815
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  • 219
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    Masthead (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300901
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  • 220
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    A New Efficient Synthesis of the Stilbenoid Laser Dyes BPS and Stilbene I by Palladium-Catalyzed Coupling of Ethene with Bromoarenes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1193-1195 
    Details
    ISSN: 0009-2940
    Keywords: Stilbene ; 4.4′-Diarylstilbenes ; Palladium ; Pd-catalyzed ; C-C coupling ; Dyes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The palladium-catalyzed coupling of ethene with 4-bromobiphenyl and 4′-bromo-4-biphenylsulfonic acid permits a facile one-pot preparation of the laser dyes (E)-4,4′-diphenylstilbene (BPS, 3) and bis(triethylammonium) (E)-4,4′diphenylstilbene-4″,4″-disulfonate (6) in diastereomerically pure form on a multigram scale, with yields of 69 and 64%, repectively. The latter can easily be transformed to its dipotassium salt 7, the Stilbene I dye.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300905
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  • 221
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    Tellurium Polycations Stabilized by Halogenobismutates - Syntheses and Crystal Structure of te4[bi6Cl20] and te4[bi2br8] (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1189-1192 
    Details
    ISSN: 0009-2940
    Keywords: Tellurium ; Bismuth ; Tetratellurium(2+) ; Halogenobismutates(III) ; Crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of Te, TeX4 and BiX3 [X = Cl, Br] in sealed, evacuated glass ampoules in the temperature range 170° 100°C yields a variety of compounds composed of tellurium polycations and halobismutate anions. Two of these have been identified by crystal structure analyses as Te4[Bi6Cl20] (triclinic, P., a = 738.8(2), b = 875.1(2), c = 1389.1(6) pm, α = 87.89(2), β = 82.87(4), γ = 87.89(2) ·, Z = 1) and Te4[Bi2Nr8 (triclinic, P., a = 726.0(4), b = 773.7(4), c = 901.8(5) pm, α = 92.95(2), β = 102.23(2), γ = 92.87(2)., Z = 1). Both compounds were obtained as black crystals with a violet lustre and contain square-planar Te42+ cations. Te4[Bi6Cl20] contains a two-dimensional polymeric anion [Bi6Cl20]2- made up of corner- and edge-sharing BiCl6 octahedra with attached BiCl3 groups. The Bi-Cl distances vary over a very wide range from 245 to 334 pm. Te4[Bi2Br8] consists of a onedimensional chain [BiBr2Br4/2-[n of cis-edge-connected BiBr6 octahedra with Bi-Br distances ranging from 264 to 318 pm.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19971300904
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  • 222
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    A New Lithium 5-Methyl-1,3-dithia-5-azacyclohex-2-ylborate  - 5-Borane and Two Dimeric 5-Methyl-1,3-dithia-5-azacyclohex-2-yllithium Compounds  -  Stereochemistry and Reactivity (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 813-817 
    Details
    ISSN: 0009-2940
    Keywords: Lithium 5-Methyl-1,3-dithia-5-azacyclohex-2-ylborate - 5-borane ; 5-Methyl-1,3-dithia-5-azacyclohex-2-yllithium ; Nitrogen heterocycles ; Sulfur heterocycles ; Lithium ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses of the dimers of axial 5-methyl-2-dithiazinyllithium (4) and equatorial 5-methyl-2-diethiazinyllithium-5-borane (5), and lithium 5-methyl-2-dithiazinanylborate-5-borane (6) are reported. Compounds 4, 5, and 6 are configurationally and conformationally stable. The 1H-, 13H-, 13C-, 11B-, and 7Li-NMR study of th reactions of 4 and 5 with BH3—S(CH3)2, BH3 - THF, and CH3I is presented.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300622
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  • 223
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    Organoamido- and Aryloxo-Lanthanoids, 17Part 16: Ref. Novel Low-Coordinate Lanthanoid (II) and -(III) Aryloxide Complexes - the X-ray Structures of Bis (2,6-diphenylphenolato) tris(tetrahydrofuran)-ytterbium (II), Bis(1,2-dimethoxyethane)bis(2,6-diphenylphenolato)ytterbium(II),-neodymium(III) (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 851-857 
    Details
    ISSN: 0009-2940
    Keywords: Lanthanoid complexes ; Ytterbium ; Neodymium ; 2,6-Diphenylphenolate complexes ; Aryloxide complexes ; Lanthanoides ; O ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reduction of [Yb(Odpp)3(THF)2(HOdpp = 2,6-diphenylphenol; THF = tetrahydrofuran) with ytterbium powder and mercury metal yields [Yb(Odpp)2(THF)3] (1) which on crystallization from DME gives [Yb(Odpp)2(DME)2] (2) (DME = 1,2-dimethoxyethane). Crystallization of the reactant [Yb(Odpp)3(THF)2] from DME yields [Yb(Odpp)3(DME)]. (DME)0,5 (3) and of [Nd(Odpp)3(THF)2] from DME/THF the analogous [Nd(Odpp)3(DME)]. (THF) (4). The X-ray crystal structure of 1 reveals distorted trigonal bipyramidal five-coordinate ytterbium with axial Odpp ligands [O-Yb-O 164.6(3)˚], and unsymmetrically distributed equatorial THF ligands [O-Yb-O 137.5(3), 138.8(3), 83.7(4)°] owing to two close H(Ph)...Yb approaches (3.1-3.2 Å). In 2, there is trigonal prismatic six-coordination with an Odpp ligand on each triangular face and DME ligands bridging the triangular faces. Both 3 and 4 have distorted square planar five-coordination for the lanthanoid metals with an apical Odpp ligand and cisoid Odpp ligands and a chelating DME in the square plane.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300707
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  • 224
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    Bis[2-(oxazolinyl)phenolato]oxovanadium(IV) Complexes: Syntheses, Crystal Structures and Catalyses (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 887-890 
    Details
    ISSN: 0009-2940
    Keywords: Asymmetric catalysis ; Epoxidation ; Oxidation ; Vanadium ; Sulfur ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The syntheses and X-ray crystal structures of two chiral bis[2-(oxazolinyl)phenolato]-oxovanadium(IV) complexes are reported. Their catalytic activity in oxidative transformations and C-C bond-forming reactions has been investigated.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300712
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  • 225
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    Investigation of Host-Guest Interactions between Rubidium Salts and N-(Arylazoalkenoyl)azacoronands by Solid-State NMR SpectroscopyDedicated to Professor Dr. Reiner Radeglia on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1625-1627 
    Details
    ISSN: 0009-2940
    Keywords: N-(Arylazoalkenoyl)azacoronands ; Rubidium Salts ; Host-guest interaction ; 87Rb MAS NMR spectroscopy ; 13C CPMAS NMR spectroscopy ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Rubidium salts with N-(Arylazoalkenoyl)azacoronands (2a-c), were investigated using 87Rb and 13C solid-state NMR spectroscopy. From the NMR results it is concluded that there is a host-gust interaction. This suggests that the rubidium and ammonium ions, respectively, are incorporated into the cavity between the coronand and the chromophore.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971301111
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  • 226
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    P/O Ligand Systems: Facile Synthesis, Structure, and Catalytic Tests of 2′-Phosphanyl-1,1′ -phenyl-2-ols and 2′-Phosphanyl-1,1′-binaphthyl-2-ols (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1663-1670 
    Details
    ISSN: 0009-2940
    Keywords: Lithiation ; P ligands ; NMR spectroscopy ; Molecular structure ; Hydrogenations ; Hydroformylations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A facile synthesis of 2′-phosphanyl-1,1′-biphenyl- and 2′-phosphanyl-1,1′ -binaphthyl-2-ols and their silyl ethers has been developed, consisting of electron-transfer-catalyzed ring-opening of dibenzofuran and dinaphthofuran, respectively, subsequent reaction with chlorophosphanes, and work-up with acetic acid or ClSiMe3. Studies of the molecular and crystal structures reveals the presence of P - H - O bridging bonds in the more basic tBuPhP derivative and a nearly perpendicular arrangement of the aryl planes in the biphenyl derivatives. The barrier to rotation of the aryl planes about the C-C axis was determined by NMR in the case of the P-asymmetric derivative 3d, using the appearence of diastereoisomers by atropisomerism and P-asymmetry. Comparative screening tests of the title compounds, phosphanyl phenols and phosphanylnaphthols in homogeneous Rh-catalyzed reactions demonstrate catalytic activity in hydroformylation reactions and superior properties of the biphenyl- and binaphthyl-2-ol derivatives in relation to other P-O ligands.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971301118
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  • 227
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    The Equilibrium Between 2-Lithium-Oxazole(-Thiazole, -Imidazole) Derivatives and Their Acyclic Isomers - A Structural InvestigationDedicated to Professor Dr. D. Seebach on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1213-1221 
    Details
    ISSN: 0009-2940
    Keywords: 2-Li(ZnCl)-substituted oxazoles (thiazoles, imidazoles) ; Acyclic isomers ; NMR spectroscopy ; Lithium ; Zinc ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Metallated oxazoles, thiazoles and imidazoles are of interest for the preparation of derivatives of the respective heterocycles, and - especially in the case of metallated thiazoles - as acyllithium equivalents in organic syntheses. Metallation at C2 of these compounds, however, often leads (more so with Li-oxazoles than with Li-thiazoles and Li-imidazoles) to products derived from the acyclic isomers of the metallated heterocycles. In order to obtain more information on the positions of the relevant equilibria, we have carried out a 13C-NMR study of substituted li- and ZnCl-oxazoles, Li-thiazoles and Li-imidazoles. In the case of Li-oxazoles, the equilibrium is completely on the side of the acyclic isomers. Addition of ZnCl2, however, leads to ring-closure, and, even in the case of 2-ZnCl-substituted benzoxazole, only the ring-closed isomer is observed. This demonstrates a dramatic gegenion effect on the equilibrium between two isomeric anions. In the case of Li-thiazoles, depending on the substitution pattern, either solely the ring-closed or an equilibrium with the ringopened isomer is observed. In the series of Li-imidazoles, only the 2-lithiated benzimidazole is in equilibrium with its ring-opened isomer. The tendency of these compounds to undergo ring-opening parallels the leaving group properties of the various subunits [OLi 〉 SLi 〉 R2NLi, and phenyl-O(S, NR)Li 〉 vinyl-O(S, NR)Li]. The difference between the effects of Li+ vs. ZnCl+ in the (benz)oxazole series is in agreement with results of solid-state structure investigations of 2-lithiated and a 2-zincated thiazole: in the Li compound the C-S bond is 2.9 pm longer than in the ZnCl species, indicating a more facile C-S bond cleavage with Li+ as the gegenion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300908
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    The First Monofluorenyl Zirconium Trichloride (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1231-1234 
    Details
    ISSN: 0009-2940
    Keywords: Fluorenyl ; Zirconium ; Ether-functionalized fluorenyl ligand ; Chloro-bridged dimer ; Spiro compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The monofluorenyl zirconium complex [(.(5):.1-C13H8CH2CH2OMe)ZrCl2(μ-Cl)]2, (2), has been obtained bby reaction of the respective fluorenyl lithium derivative with ZrCl4 in diethyl ether. A single-crystal X-ray structural analysis shows that 2 is a chloride-bridged dimer, in which the fluorenyl ligand is bonded in a transitional tri- to pentahapto fashion. The relatively weak fluorenyl-zirconium bond is stabilized by intramolecular coordination of the ether sidechain attached to the fluorenyl backbone. Despite this, the bidentate ligand is easily detached upon dissolution of 2 in THF. Simultaneous ether cleavage produces spiro[cyclopropane-1,9′-fluorene].
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300910
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    Diastereoselective Synthesis of the First Enantiomerically Pure (Triazolinylidene)ruthenium(ii) and -rhodium(iii) Chelate Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1253-1260 
    Details
    ISSN: 0009-2940
    Keywords: Chiral carbenes ; (Carbene)ruthenium complexes ; (Carbene)rhodium complexes ; Chelate Complexes ; Chirality ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chloro bridges of the dinuclear complexes [(.65-cymene)-RuCl2]2 and [(.5-C5Me5)RhCl2]2 can be cleaved by reaction wht an N-phenyltriazolium perchlorate (1) and a base, resulting in the formation of (carbene)metal complexes. In this manner, abstraction of one ortho-proton of the phenyl group and elimination of HCl leads to pseudo-tetrahedral ruthenium (2) and rhodium (3) complexes, thereby creating a stereogenic center at the transition metal. By using enantiomerically pure triazolium perchlorates, the diastereoselective synthesis of these complexes with diastereomeric excesses of up to 95% can be achieved, with the possibility of separating the two diastereomers by column chromatography. The relative, and therefore also the absolute configuration of the ruthenium complex (RRu)-2b could be determined by X-ray structure analysis. A stereospecific substitution of chlorine by iodine or acetonitrile to form the diastereomerically pure complexes 4, 5 and 6 (the latter as cationic ruthenium complexes) allows a further variation of the ligands.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300913
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    New Borylene Complexes of the Type [μ-BX{.5-C5H4Me)MN(CO)2}2]: Substitution Reactions at the Metal-Coordinated Borylene Moiety (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1295-1298 
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    ISSN: 0009-2940
    Keywords: Boron ; Manganese ; Borylene complexes ; Reactions at metal-coordinated boron ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of the air- and water-stable borylene complex [μ-BNMe2{.5-C5H4Me)Mn(CO)2}2] (1a) with a solution of Hcl in Et2O affords the correspondin chloroborylene complex [μ-Chloroborylenebis{dicarbonyl(.5-methylcyclopentadienyl)manganese}(Mn-Mn)] (2). This compound easily undergoes further substitution reactions with protic reagents such as primary amines, alcohols and water at the metal coordinated borylene moiety with elimination of HCl, giving new products of the type [μ-BX{.4-C5H4ME)Mn(CO)2}2] (3a, ab: X=NHtBu, NHPh; 4a, b: × = OMe, OEt; 5: X= Oh}. All borylene complexes were isolated as crystalline solids in good yield and characterized by multinuclear NMR methods and IR spectroscopy in solution. In addition, the structure of 4b in the crystalline state was determined by a single-crystal X-ray study.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300918
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  • 231
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    Coordination Polymers, 13. Induction of Helicity via Stereogenic Centers: Asymmetric Synthesis of (P)- and (M)-Coordination PolymersDedicated to Professor Wolfgang Beck on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1309-1313 
    Details
    ISSN: 0009-2940
    Keywords: Asymmetric induction ; Helical structures ; Coordination polymers ; Copper ; Crystal structures ; Clathrates ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of a methanolic copper(II) acetate solution of enantiomerically pure (5R)-/(4S)-methyl E-(4-ethyl-2-oxazolidinylidene)cyanoacetate 6 leads to the mononuclear chelate complexes (R, R)-/ (S, S)-7. Recrystallization of (R, R)-/(S, S)-7 from non-coordinating chloroform and asymmetric induction via the stereogenic centers, originating from (R)-/(S)-6, stereospecifically yield the right- and left-handed helical ID-coordination polymers (P)-/(M)-8. The structures of mononuclear complex (R, R)-7 and of helix (P)-8 and its mirror image (M)-8 have been characterised unequivocally by X-ray crystal structure analyses. (P)- and (M)-8 crystallize with chloroform to give the clathrates 1.{[CuLR2]. 2 CHCl3} and 1.{[CuLS2].2CHCl3}, respectively.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300921
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    Phosphane Ligands, 6 The Remarkable Tridentate Coordination of 4,6-Bis(diphenylphosphanyl)-dibenzofuran in Ruthenium(II) Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1315-1319 
    Details
    ISSN: 0009-2940
    Keywords: Ruthenium ; Chelating diphosphane ligand ; Phosphane ; Dibenzofuran ; Tridentate ligands ; X-ray scattering ; Crystal engineering ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 4,6-Bis(diphenylphosphanyl)dibenzofuran (1), despite its large P…P distance of 5.74 Å and its bite angle of ca. 131° was found to be Capable of tridentate coordination to ruthenium (II) chloride. Single crystal X-ray structure analyses of the new ruthenium (II) complexes 3,4 and 5 revealed that the ligand 1 coordinates to a single ruthenium atom with both phosphorus centers and the dibenzofuran oxygen atom. The remarkable ligand deformation resulting from the coordination is evident from the decrease of the P…P distance by 1 Å to 4.75 Å and the increase of the bite angle (P-Ru-P) by 25° to 155°-157. The unprecedented in-plane coordination of the dibenzofuran oxygen atom to ruthenium is interesting in view of the hybridisation of the oxygen.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300922
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    Cyclocarbonylation of Bicyclic Vinylcyclopropanes - Selective Generation of Seven-Membered Enones (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1339-1341 
    Details
    ISSN: 0009-2940
    Keywords: Pentacarbonyl iron ; Carbonylations ; Insertions ; Bicyclo[4.1.1]octenones ; Bicyclo[3.2.1]octenes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The cyclic vinylcyclopropane 6a reacts at elevated temperatures with iron pentacarbonyl to selectively give the enone 7a in 52% yield. Reducing the reaction time provided the isomeric ketones 7a-b. Partial chromatographic separation of this mixture allowed the complete spectroscopic identification of 7b by 1H NMR. The structure of 7c was determined from selected spectral data of the mixture of 7a and 7c. For comparison, the methyl substituted derivate 6b was subjected to a carbonylation under the above conditions exclusively providing 8 ini 42% yield. A mechanistic rationale for the two different modes of ring opening is presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300926
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    Masthead (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971301001
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    Synthesis and Electrochemistry of Diels-Alder Adducts of [60] Fullerene with a Phthalocyanine and a Hemiporphyrazine (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1375-1378 
    Details
    ISSN: 0009-2940
    Keywords: Phthalocyanines ; Hemiporphyrazines ; Fullerenes ; Diels-Alder reactions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of a new Diels-Alder adduct 7 of [60]fullerene and a phthalocyaninenickel compound containing a longer spacer than the originally reported Diels-Alder adduct 1 is described. The bisenophilic hemiporphyrazinenickel compound 11 reacts with [60]fullerene to form a Diels-Alder adduct 12 containing two fullerene units. Spectroelectrochemical investigations of 7 and 12 reveal multiple reductions, which are attributed to the corresponding subunits of the molecules. In contrast to 1, the election acceptor properties of the [60]fullerene unit in both molecules have no influence on the electronic properties of the phthalocyanine and hemiporphyrazine, respectively.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971301005
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    1-Hexene Hydroformylation with the Rhodium (I) Triphosphane Complex [Rh(CO){PhP(CH2CH2PPh2)2}]PF6: An In Situ Study Using High-Pressure NMR Spectroscopy (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1633-1641 
    Details
    ISSN: 0009-2940
    Keywords: Hydroformylation ; High-pressure NMR ; Homogeneous catalysis ; Rhodium ; Polyphosphane ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rhodium-catalyzed hydroformylation of 1-hexene in THF with the linear triphosphane PhP(CH2CH2PPh2)2 [PP,] has been studied both in situ and in high-pressure autoclaves. Sapphire NMR tubes with titanium valves have proved useful for studying the in situ reactions under conditions of relatively high syngas pressure (30-90 atm H,/CO) and temperature (60-100 C). Under conditions conducive to effective hydroformylation, the catalyst precursor [ (PP,)Rh(CO)]+ is quantitatively converted to the dicarbonyl [ (PP,)Rh(CO),]+, which is also the termination product of the catalysis. Irrespective of the syngas composition and of the total pressure, the dicarbonyl complex is the only phosphorus-containing species detectable on the NMR time-scale during the course of the isomerization and hydroformylation of the alkene. The PP2-Rh catalytic system exhibits some peculiar features that may be summarized as follows. (i) Very high partial pressures of CO (120 atm) neither inhibit the hydroformylation nor affect the n/i selectivity; (ii) alkene hydrogenation occurs neither at very high partial pressures of H, (120 atm) nor in the absence of added CO; (iii) the isomerization rate is slightly faster than that of hydroformylation; (iv) terminal and internal alkenes (2-, 3-hexenes) are hydroformylated with comparable rates. Various control experiments have been carried out using in-situ NMR, as well as batch experiments under different reaction conditions or with different catalyst precursors. Despite these extensive studies, unambiguous conclusions about the catalysis mechanism have not been reached. In particular, the possibility that different catalysts may be operative depending on the reaction conditions cannot be ruled out. The hydroformylation results rule out the involvement of phosphane-free “Rh-CO” catalysts, even under conditions of very high partial pressure of CO, and point to “(PP,)Rh(CO),” catalysts with small steric hindrance over the whole range of syngas pressures investigated.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971301113
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  • 237
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    Masthead (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971301201
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    Coordination Chemistry of PentahalocyclopentadienylsThis article is dedicated to Professor Wolfgang Beck on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1721-1730 
    Details
    ISSN: 0009-2940
    Keywords: Perhalometallocenes ; Cylopentadienes ; Perhalogenated ; Halogen-metal exchange reactions ; Sandwich complexes ; Ligand effects ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The coordination chemistry of perhalocyclopentadienyl ligands, first developed in the early 1970's as a part of a research program directed towards the synthesis of oxidation-resistant fuel additives, has been revived in the last ten years. This renewed interest stems from the discovery that the coordinated cyclopentadienyl ligand allows multiple functionalizations. Thus, the high versatility of this important class of ligands can be broadened even further, which may be important with regard to industrial applications of metallocenes.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971301203
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    Density Functional Studies on Amino-Substituted Methane and Silane (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1745-1749 
    Details
    ISSN: 0009-2940
    Keywords: Density functional calculations ; Tetra(amino)methane ; Tetra(amino)silane ; Transition states ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In all-electron density functional calculations on mono- and tetraaminosubstituted methane and silane the coordination around the nitrogen center is found, in complete agreement with experiment, to be less pyramidal in the silicon compounds. The calculated barrier to inversion at nitrogen is only 0.6 kcal/mol in silylamine, while in methylamine it is 5.5 kcal/mol. The larger flexibility is attributed to the greater ionic character of the Si-N bond compared to that of the C-N bond. In tetra(amino)methane, inversion of one amino group leads to a local minimum (calculated inversion barrier: 6.4 kcal/mol), while a corresponding structure (or barrier) does not exist for the silicon compound. Due to the steric influence of the amino groups, the barrier to rotation around the C-N bond is larger in the tetrasubstituted compound (6.4 kcal/mol compared to 2.3 kcal/mol in methylamine). While the average binding energy of the amino groups is similar in both tetra(amino)compounds, the binding energy of the fourth ligand is about 25% larger in the silicon compound for both homolytic and heterolytic bond cleavage. This difference arises from the relative stabilization of the tri(amino)-methyl species, due to some n contribution to the C-N bond.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971301207
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    Phosphanyl-Substituted Phosphaferrocenes as p,p-Chelate Ligands (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1771-1776 
    Details
    ISSN: 0009-2940
    Keywords: Chelates ; P ligands ; Phosphaferrocene ; Carbonyl complexes ; Heterocycles ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dicyclohexyl-acid diphenylphosphanyl-substituted phosphaferrocenes 2 and 3 were synthesized by substitution of the amino group in 2-dimethylaminomethyl-3,4,-dimethylphosphaferrocene 1 · Homologization of 2-formyl-3,4-dimethylphosphaferrocene 4 by one CH2 unit via Wittig olefination provided access to the phosphanylethyl derivative 9. Ligands 2, 3 and 9 formed P, P-chelate complexes with tetracarbonyl metal fragments in good yield. X-ray crystal structure determinations were carried out for the five-ring chelate complex 2. Mo(CO)4 (≡ l0), and the six-ring chelate complex 9 . Mo(CO)4, (≡ 13).
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971301211
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    Synthesis and Reactions of Bis (4,5-benzo-1,3-dioxa-2-phospholano)dichlormethaneDedicated to Professor Hans-Georg Meier on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1479-1483 
    Details
    ISSN: 0009-2940
    Keywords: Bisphosphane, bisdichloromethylene-bridged ; Oxidation with tetrachloro-o-benzoquinone(TOB) ; σ 6 λ5-phosphorate ; Phosphorus Heterocycles ; Structure elucidation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The title compound 3 was formed in the reaction of Cl2PCCl2PCl2 (2) with catechol in the presence of triethylamine. The reaction of 3 with tetrachloro-o-benzoquinone (TOB), 4, led to the σ3P/σ5P-species 5, and the σ5P/σ5P-species 6a/6b. 5 was stable only in solution, and its existence and identity are postulated on the basis of its 31P-NMR spectrum. The structure of 6a/6b could not be assigned unambiguously to one isomer. The reaction of 6a/6b with water yielded the phosphorate 10. The structures of 3 and 10 were determined by single crystal X-ray methods. A wide P—C—P angle (123.2°) was observed in 3. The cation of 10 is a centrosymmetric, protonated DMF dimer with O—O 241.3 pm.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971301020
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    A Theoretical Investigation of Cycloadditions of Hydrogen Isocyanide to CH2=X and PH=X Dipolarophiles (X = CH2, NH, O, SiH2, PH, S)We dedicate this paper to the memory of our friend and colleague, Prof. Dr. Gerrit L'Abbé, who untimely passed away on August 27, 1996. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 69-76 
    Details
    ISSN: 0009-2940
    Keywords: [2 + 1] Cycloadditions ; Hydrogen cyanide ; Phosphorus dipolarophiles ; Three-membered rings ; Calculations, ab initio ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We performed a systematic investigation of [2 + 1] cycloadditions of HN≡C to dipolarophiles of the type CH2=X and PH=X with X=CH2, NH, O, SiH2, PH, and S, as well as HN=NH and H2Si=SiH2. Ab initio MO calculations at the QCISD(T)/6-311G(d,p)/MP2/6-31G(d,p)+ZPE level were applied to construct the minimum-energy reaction pathways. Calculated results concerning the regiochemistry of the approaches and the stereochemistry of the product formation were analyzed in relation with established concepts such as frontier orbital, net charge distribution and stereoelectronic effect. For some systems, up to four distinct transition structures for cycloaddition were found. In general, there is a certain similarity between the behavior of both C and P series of dipolarophiles. The characteristics of the transition structures can be, in most cases, recovered by using qualitative concepts. The [2 + 1] cycloadditions are highly regioselective and stereospecific. Silicon-containing dipolarophiles are particularly attractive as they exhibit very small energy barriers to addition to isocyanides.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300111
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    Triphenylphosphonio-Substituted 1,2,3,4-Triazaphospholes and 1,2,4-Diazaphospholes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 89-94 
    Details
    ISSN: 0009-2940
    Keywords: (Triphenylphosphonio)phosphaethyne ; Azides ; [3 + 2] Cycloadditions ; Phosphonio-1,2,3,4-triazaphospholes ; Diphosphonio-1,2,4-diazahospholes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several products resulting from the condensation of the bis-(trimethylsilyl)ylide 1 with PCl3 serve as synthetic equivalents of a phosphoniophosphaethyne. Cycloaddition reactions with azides lead to phosphonio-1,2,3,4-triazaphosphole cations 5, 7 and to the zwitterionic phosphonio-1,2,3,4-triazaphospholide 6. The latter readily undergoes a cycloreversion yielding a phosphoranediyl diazomethane 12 as intermediate. Its cycloaddition affords the diphosphonio-1,2,4-diazaphosholide chloride 9a as the final product. 9a is a remarkably stable and unreactive derivative of the two-coordinate phosphorus. By HCL it is protonated at a nitrogen atom to give dication without any tendency to associate with the chloride counterions.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19971300114
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    Tris(phenylthiomethyl)phosphane Sulfide and Selenide, (PhSCH2)3PX (X = S, Se), as Ambidentate Ligand Systems in Copper(I) Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 105-110 
    Details
    ISSN: 0009-2940
    Keywords: Sulfides ; Selenides ; Copper complexes ; Ambidentate ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Triphenylphosphite has been converted into tris(phenylthiomethyl)phosphane (1) by reaction with LiCH2SPh/DABCO, and subsequently into the corresponding sulfide (2) and selenide (3) by treatment with elemental sulfur or selenium, respectively. Ligands 2 and 3 react with copper(I) halides CuX (X = Cl, Br, I) in polar organic solvents to give either 1:1 (X = Cl: 4, 7, X = Br: 5, 8 ) or 1:2 complexes (X = Br: 9, X = I: 6, 10). The crystal structures of five of these complexes have been determined by single crystal X-ray diffraction studies. All compounds of the type [(PhSCH2)3P=S/Se]CuX (X = Cl, Br) form centrosymmetrical dinuclear complexes featuring a four-membered ring core Cu2[S/Se], fused to two five-membered rings Cu[S/Se]PCS through common trans edges. Only one of the three phenyl-thiomethyl functions is involved in coordination to a metal center. The compound [(PhSCH2)3P=S](CuI)2 (6) is associated into a centrosymmetrical tetranuclear complex containing two four-membered rings (ICu2S) bridged via iodine atoms in 1,3-cis positions. The ligand is found to employ two of its PhSCH2 functions for metal coordination, giving rise to two five-membered rings fused to the four-membered rings via neighbouring edges. In all cases, therefore, the P=S/Se functions of the ligands are the preferred donor sites, which are used for the building of bridgehead structural units of polynuclear complexes.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300117
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    A Series of Carbonyl-, Olefin-, Alkyne-, Hydrido-, and Vinyliridium Complexes Containing Bulky Bifunctional Phosphanes iPr2PCH2X as LigandsDedicated to Professor Hans Bürger on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1591-1603 
    Details
    ISSN: 0009-2940
    Keywords: Iridium ; Hydrido complexes ; Olefin complexes ; C-H activation ; P ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Etheneiridium(I) complexes of the general composition trans-[IrCl(C2H4)L2] [L = iPr2PCH2CO2Me (2a), iPr2PCH2CO2Et (2b), iPr2P(CH2)3NMe2 (2c)] have been prepared either from [IrClL2] (3) or [IrCl(C2H4)2]2 (7) as starting materials. The corresponding carbonyl derivatives trans-[IrCl(CO)L2] (6, 10, 11) are obtained along similar routes. Photolysis of trans-[IrCl(C2H4)L2] (L = 2a, 2b) leads, by intramolecular C-H activation, to the formation of the octahedral hydrido(vinyl)iridium(III) compounds [IrHCl(CH=CH2)(k-L)(k2-L)] (16, 17), which are highly fluctional in solution. Carbonyl(hydrido)(vinyl) complexes are accessible either from 16 or 17 and CO, or from trans-[IrCl(C2H4)L2] (L = 2a) and the propargylic alcohol HC≡CCH(Ph)OH, respectively. Treatment of 3 or the corresponding dihydrido compound [IrH2ClL2] (4) with methyl vinyl ketone or methyl acrylate also yields hydrido(vinyl)iridium(III) complexes [IrHCl(CH=CHX)L2] [X = C(=O)Me (18), C(=O)OMe (19)], in which instead of the C=O function of the phosphanyl ester the carbonyl group of the vinylic moiety is coordinated to the metal. The reaction of 16 (L = 2a) with terminal alkynes HC≡CR (R = Ph, CO2Me) affords the structurally related alkynyl(hydrido)iridium(III) compounds [IrHCl(C≡CR)(k-L)(k2-L)] (28, 29), while from 16 and internal alkynes RC≡CR) the iridium(I) complexes trans-[IrCl1(RC≡CR)L2] (30, 31) are obtained, Stepwise treatment of trans-[IrCl(RC≡CR)L2] (6: L = 2a) with NaN(SiMe3)2, (ii) H2O, and (iii) HCl leads, in the coordination sphere of the metal center, to a conversion of iPr2PCH2CO2Me to iPr2PCH2CO2H via the isolated phosphanylenolate and phosphanylacetate complexes 32 and 33 as intermediates.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971301107
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    Steric Effects on Base Adduct Formation and Crystal Structures of Diastereomers of a Nickel(II) Schiff Base Complex (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1643-1646 
    Details
    ISSN: 0009-2940
    Keywords: Nickel Schiff base complexes ; Base adducts ; Chirality ; Steric hindrance ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of the ligand meso-H2L, derived from cis-diaminocyclohexane and ethyl cyano(ethoxymethylene)acetate, with nickel(II) acetate gives meso-NiL. Spectrophotometric titration of RR-NiL and meso-NiL with various nitrogen bases reveals a strong influence of the steric hindrance of the diaminocyclohexanediyl bridge in meso-NiL on the base adduct stability. The structures of RR-NiL and meso-NIL have been established by X-ray diffraction.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971301114
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    Metal Complexes of Biologically Important Ligands, XCIV. Hexanuclear Isocyanide and Carbene Metal Complexes from Neomycin BDedicated to Professor Armin Weiß on the occasion of his 70th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1659-1662 
    Details
    ISSN: 0009-2940
    Keywords: Hexadeamino-hexaisocyano-neomycin B ; Organometallic complexes ; Gold ; Chromium ; Rhodium ; Iridium ; Ruthenium ; Palladium ; Platinum ; Hexanuclear carbene gold(I) complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: From the amino glycoside neomycin B, the acetate-protected hexaisocyanide 4 has been prepared. 4 forms the hexanuclear complexes [(4)(AuCl)6] (5), {(4)[Cr(CO)5]6}, {(4)[MCl2(η5-C5Me5)]6} (M = Rh, Ir), {(4)[RuCl2(p-cymene)]6}, {(4)-[MCl2(PR3)]6} (M=Pd, Pt), and 4{(4)[PdCl(C6H4CH2NMe2)]6). The hexaisocyanohexagold(I) complex 5 reacts with H2NtBu and PhNH2 to give the corresponding carbene complexes. The compounds have been characterized by IR, 13C- and 31P-NMR spectroscopy, and (partially) by FAB-MS data.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19971301117
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    Coordination Chemistry of Functional Phosphanes, VI. Rhodium and Iridium Complexes with 2-(Diphenylphosphophanyl)phenylamido Ligands (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1693-1698 
    Details
    ISSN: 0009-2940
    Keywords: P,N ligands ; Rhodium complexes ; Iridium complexes ; Hydrogen bonding ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Treatment of trans-[MCl(CO)(PPH3)2] (M = Rh, Ir) with the lithium salts fof the bidentate hybride ligands 2-Ph2PC6H4N(R)H [‘PN(R)H’ R = H, Me] produced the chelate complexes [M(CO)(PPH3)(‘PNR’)] [M/NR = Rh/NH (1a), Ir/ NH (2a), Rh/NMe (1b), Ir/NMe (2b)] containing the CO ligand and the NR substituent in mutual trans-arrangement. 2b was shown by single-crystal X-ray diffraction to possess an amido-nitrogen atom in a trigonal-planar environment. Oxidative addition of H2 to 2b reversibly formed cis-[IrH2(CO)(PPh3)(‘PNMe’)] (3), in which H2 has added perpendicular to the N-Ir-CO axis. While both 1a,b and 2a, b proved to the completely unreactive toward CO2 at ambient temperature and pressure, reactions of 1a and 2a/b with sulfur dioxide reversibly formed pentacoordinate SO2 adducts, [M(SO2)(CO(PPh3)(‘PNR’)][M/NR = Rh/Nh (4a), Ir/NH (5a), Ir/NMe (5b) with M-S-bonded pyramidal MSO2 units as established by an X-ray structure analysis of 5a. Complex 5b reacted with dioxygen to form the sulfato compound [Ir(O2SO2)(CO)(‘PNMe’)] (6). Combination of 2a with HCl in CHCl3 at -60°C resulted in protonation of both the iridium and the nitrogen atom to give an ionic chelate complex, [IrHCl(CO)(PPh3)(‘PNH2’)]Cl (7), containing one of its NH groups hydrogen-bonded to Ir-Cl. Ring opening of the chelate structure with formation of [IrHCl2(CO)(PPh3)(PPh2C6H4N(Me)H-o)] (8) was observed in the analogous reaction of 2b with hydrogen chloride. NMR spectroscopy showed 8 to exist in CDCl3 solution as a mixture of three Ir-PPh2C6H4N(Me)H-o rotamers, stabilized by intramolecular -N(Me)H  - ClIr hydrogen bonding.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971301121
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  • 249
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    Cyclic Aryleneazachalcogenes, X. Synthesis, Molecular Structure and Photoelectron Spectrum of 6,7,8,9-Tetrafluoro-1,3,5,2,4-benzotrithiadiazepine and Attempted Syntheses of Related Larger Size Heterocycles[1] (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 247-253 
    Details
    ISSN: 0009-2940
    Keywords: 6,7,8,9-Tetrafluoro-1,3,5,2,4-benzotrithiadiazepine ; 1,2,3,4-Tetrafluoro-5,6-bis(1-trimethylsilyl-2,4-dithia-1,3-diaza-1,2-butadien-4-yl)benzene ; Photoelectron spectroscopy ; Semiempirical calculations ; Nitrogen heterocycles ; Sulfur heterocycles ; Fluorine compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 14π-electron title compound 7 has been synthesized by two different ring-closure approaches. Its structure has been determined by X-ray diffraction to be planar within ±0.018 Å. The He(I) photoelectron spectrum of the title compound is assigned by Koopmans' correlation with PM3 eigenvalues based on the structural data, and by the π-perfluoro effect observed. The π-system can be rationalized y heteroatom first-order perturbation, which reduces the cycli π-delocalization. Replacement of the four fluorine substituents by hydrogen affects neither the long-wavelength absorption band in the UV/Vis spectrum nor the δ15N shift in the 15N-NMR spectrum. The synthesis of 20π-electron heterocycles related to the title compound has been attempted.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300218
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  • 250
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    Tertiary Phosphane-Diiodine Compounds: Are They Molcular Adducts or Iodophosphonium Iodides? (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 299-305 
    Details
    ISSN: 0009-2940
    Keywords: Iodine ; Phosphorus ; Charge transfer ; NMR spectroscopy ; Raman spectroscopy ; Structure elucidation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The solid-state and solution structures of Ph3P · I2 have been studied in detail by electronic, 31P{1H}-NMR and Raman spectroscopy as well as conductometric measurements. When 1 : 1 ratios of triphenylphosphane and diiodine are mixed in dichloroethane, the molecular adduct is shown to exist also in solution. On the basis of the overall results, this molecular adduct is best described as a charge-transfer complex of the donor I- with the acceptor Ph3PI+, rather than the charge-transfer complex of the donor Ph3P with the acceptor I2 or the ionic species [Ph3PI]I as previously proposed. When higher diiodine to triphenylphosphane ratios are used, the Ph3P · I2 adduct dissociates to give Ph3PI+ and I3- or I5- depending on the diiodine excess. Previously reported solution data, which were ascribed to the ionic form of the adduct, are instead in agreement with hydrolysis products (Ph3PO, PH3POH+) of the very reactive adduct, formed in the presence of traces of water.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300226
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  • 251
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    Tris(dimethylamino)phosphane as a New Ligand in Gold(I) Chemistry: Synthesis and Crystal Structures of [(Me2N)3P]AuCl, {[(Me2N)3PAu]3O}+BF4-, {[Me2N)3PAu]3NP(NMe2)32+ {BF-4}2 and the Precursor Molecule (Me2N)3PNSiMe3 (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 323-328 
    Details
    ISSN: 0009-2940
    Keywords: Gold ; Phosphanes ; Phosphaneimines ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [Tris(dimethylamino)phosphane]gold(I) chloride, μ-tris-{[tris(dimethylamino)phosphane]gold(I)}oxonium tetrafluoroborate, {μ3-tris(dimethylamino)phosphaneimidotris[tris(dimethylamino)phosphane]gold(I)}(2+) bis(tetrafluoroborate) and N-trimethylsilyltris(dimethylamino)phosphaneimine were prepared using modifications of established procedures. Their structures were determined in single-crystal X-ray diffraction studies. The ligand (Me2N)3P, here introduced into gold(I) chemistry for the first time, lends high stability to these compounds through efficient steric shielding of the reaction sites and through a balanced electronic substituent effect. The structural details of the (Mr2N)3P groups are of current interest because of the unusual nonequivalent configuration of the nitrogen atoms in the dimethylamino groups. This behaviour has been observed for most of the (Me2N)3P units in the compounds studied in this work.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300304
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  • 252
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    Technetium and Rhenium Complexes with Thioether Ligands, 5. Synthesis and Structural Characterization of Neutral Oxorhenium(V) Complexes with Tridentate Dithioethers (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 357-362 
    Details
    ISSN: 0009-2940
    Keywords: Rhenium complexes ; Technetium complexes ; Radiopharmaceuticals ; Dithioether ligands ; Dithiaalcohols ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Neutral oxorhenium(V) complexes of the general formula ReO(L)Cl2 are obtained by reaction of [ReO4]- or [ReOCl4]- with functionalized dithiaalcohols (L) containing the donor atom sequences S, S, O- and S, O-, S. Ligand exchange reaction of [ReOCl4]- with HO(CH2)2S(CH2)2S(CH2)2O (R = H, Et ) leads to the formation of ReOCl2[O(CH2)2S(CH2)2-S(CH2)2OEt] (1b). Reduction of [ReO4]- with a 1:1 mixture of concentrated HCl and glacial acetic acid in the presence of nBuSCH2- CH(OH)CH2S-nBu yield ReOCl2[OCH(CH2S-nBu)2) (4). X-ray structure analysis of 1a, 1b and 4 shows distorted octahedral coordination with the chlorine and sulfur atoms in the equatorial plane. The oxygen of the hydroxyl group coordinates in a trans position with respect to the Re=O core. 1a reacts with an excess of acetyl chloride in an unexpected way, resulting in cleavage of the trans Re-O bond and acylation of both of the hydroxyl groups to form the μ-oxo bridged complex [ReOCl2{CH3COO{CH2)2S(CH2)2PPC-CH3}}2O (3).
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300309
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  • 253
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    Synthesis and Characterization of Novel Octakis(2′-aminophenoxy and 2′-Aminophenylsulfanyl)-Substituted Metallophthalocyanines (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1833-1836 
    Details
    ISSN: 0009-2940
    Keywords: Phthalocyanines ; Phthalonitrile derivatives ; Pentanuclear complexes ; Nickel ; Zinc ; Cobalt ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel phthalocyanines (M = Ni, Zn, Co) bearing eight 2′-aminophenoxy and 2′-amino phenylsulfanyl substitutents on peripheral positions have been prepared starting from 4,5-bis(2′-aminophnoxy)-1,2-dicyanobenzene and the corresponding anhydrous metal salts [NiCl2, Zn(O2CMe)2, CoCl2]- Complexation of octakis(2′-amino phenylsulfanyl)-substituted metallo phthalocyanines (2b, 3b and 4b) with Pd11 to form the pentanuclear product was accomplished from their mixtures.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971301220
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  • 254
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    Layered Ternary and Quaternary Metal ChalcogenidesDedicated to Prof. Dr. Hans Georg von Schnering on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1-8 
    Details
    ISSN: 0009-2940
    Keywords: Chalcogenides ; Reactive flux ; Layered compounds ; Structures ; Physical properties ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The syntheses, crystal structures, and physical properties of some recently discovered layered ternary and quaternary chalcogenides are reviewed. One component of these systems is an alkali metal or thallium; another is a d-, f-, or p- block metal.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300102
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  • 255
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    Hydrogen Bonding and Conformational Analysis of Chelate-Stabilized Alkoxopalladium(II) Complexes Derived from Amino Alcohol Ligands (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 35-44 
    Details
    ISSN: 0009-2940
    Keywords: Alkoxopalladium(II) ; Conformational analysis ; Hydrogen bonding ; Two-dimensional and cage structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of palladium acetate with two equivalents of di- and triethanolamines RN(CH2CH2OH)2 in the presence of a base affords the new chelate-stabilized alkoxo Pd(II) complexes [Pd(OCH2CH2N(R)CH2CH2OH)2] [R = Me (1), Et (2), n-Bu (3), benzyl (4) or CH2CH2OH (5)]. These N,O-ligated complexes are isolated in high yield as yellow, crystalline solids and are thermally stable despite the presence of several β-hydrogen atoms in the ligand system. Both complexes possess a square-planar palladium coordination geometry with the two oxygen atoms positioned mutually trans. The most notable difference in the molecular structures is that 1 forms a two dimensional network of intermolecular O-H≡O hydrogen bonds, whereas 5 forms intramolecular O-H⃛O hydrogen bonds, which cage the palladium center. In solution 1-4 exist as a diastereoisomeric mixture (a racemic enantiomeric pair SNSN, RNRN and a mesomeric form RNSN) in a 1:1 molar ratio, and this ratio is independent of temperature in nonalcoholic solvents, When complexes 1-4 are dissolved in protic solvents (e.g. MeOH) the diastereomeric excess is temperature-dependent due to an exchange process between the meso diastereoisomer and the (racemic) enantiomeric pair. Thermodynamic parameters for this process in a mixture of MeOH-toluene have been determined with NMR and show this process to be influenced by the steric nature of the alkyl substituent (R) on nitrogen. A conformational analysis based on 1H-NMR coupling constants within the N,O-chelate ring of complexes 1-4 provides details on the solution structure of the ring in both diastereoisomers.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300106
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  • 256
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    The Structural Chemistry of Binary Halogen Oxides in the Solid State (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 307-316 
    Details
    ISSN: 0009-2940
    Keywords: Halogen oxides ; Solid-state structures ; Intermolecular interactions ; Halogens ; Oxygen ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The development of new preparative and analytical techniques that allow appropriate handling and characterizations of the capricious halogen oxides have initiated a revival of their chemistry. Due to these recent activities, the amount of well-confirmed knowledge about such oxides has considerably increased. This is especially valid for the structural chemistry in the solid state, which (among other topics) has greatly benefitted from developments in the techniques of in situ crystal growth of low melting substances on a diffractometer. As a consequence, some general crystal chemical features have become apparent: The coordination polyhedra of the halogen oxides can be readily understood in terms of the qualitative VSEPR concept, and there is a pronounced tendency to form mixed valence compounds where the respective valence states can be easily deduced from the coordination polyhedra. Furthermore, intermolecular or interionic bonds are significant, with increasing importance when moving from chlorine to iodine. Finally, ClO2 appears to be the only representative with the halogen in an even oxidation state.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300302
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  • 257
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    Chiral Organometallic Reagents XXI. Stereoselective Carbenoid Cyclization Reactions (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 341-346 
    Details
    ISSN: 0009-2940
    Keywords: Carbenoids ; Carbolithiation ; Cyclization ; Cyclopropanation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dichotomy between concerted cyclopropanation and carbolithiation pathways on intramolecular carbenoid cyclopropanation reactions has been studied. These studies have been extended to the intramolecular carbenoid/aldehyde addition reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300307
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  • 258
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    Contributions of the Chemistry of Boron, 236. In Quest of New and Stable Bis(organyloxy)boranes (RO)2BH for Catalytic HydroborationDedicated to Prof. Dr. Marianne Baudler on the occasion of her 75th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 363-370 
    Details
    ISSN: 0009-2940
    Keywords: Bis(triphenylmethoxy)hydroborane ; Naphtho[2,3-d], -1,3,2-dioxaborolane ; Naphtho[1,8-de]-1,3,2-dioxaborinane ; Phenanthro[9,10-d]-1,3,2-dioxaborolane ; Dibenzol[d,g]-1,3,2-dioxaborocine ; Bis(diphenylmethoxy)borane ; Tetrachlorobenzo-1,3,2-dioxaboraolen ; Hydroborations ; Boron ; Catalysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New and stable bis(organyloxy)boranes, 1,3,2-dioxaborolanes and 1,3,2-dixoaborinanes have been prepared (i) from the corresponding diol and BH3·THF and (ii) from 1,2-diketones and BH3·THF. They were characterized by spectroscopic techniques. The BH stretching frequency seems to be a measure of ring strain and Lewis acidity. The compounds have been qualitatively tested in the transition-metal-catalysed hydroboration of cyclopentene, and the dioxaborinane 11 proved to be superior to the 1,3,2-dioxaborolanes 9 and 18.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300310
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  • 259
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    Oxozirconium Methacrylate Clusters: Zr6(OH)4O4(OMc)12 and Zr4O2(OMc)12 (OMc = Methacrylate) (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 473-478 
    Details
    ISSN: 0009-2940
    Keywords: Clusters ; Zirconium ; Metal alkoxides ; Sol-gel processes ; Carboxylato complexes ; Oxo complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The crystalline oxozirconium methacrylate clusters Zr6(O-H)4O4(OMc)12 and Zr4O2(OMc)12 were obtained by reaction of Zr(OnPr)4 with an excess of methacrylic acid and analysed by X-ray diffraction. The oxide and hydroxide groups are in a μ3- bridging mode in both structures, and the methacrylate ligands are chelating or bridging. The zirconium atoms in Zr6(OH)4O4(OMc)12 form an octahedron the cluster having crystalographic C3v symmetry. Each metal atom is square-antiprismatically coordinated by eight oxygen atoms. In Zr4O2(OMc)12, the zirconium atoms have a distorted butterfly arrangement; their coordination geometry is square-antiprismatically coordinated by eight oxygen atomes. In Zr4O2)OMc)12, the zirconium atoms have a distorted butterfly arrangement; their coordination geometry is square-antiprismatic or capped octahedral.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300406
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  • 260
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    New Five- and Six-Coordinate Nitrosylosmium(0) and Nitrosylosmium(II) Complexes Prepared from the Stable 16-Elektron Species [OsCl(NO)(PR)(PR3)2]Dedicated to Professor Waldemar Adam on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 493-506 
    Details
    ISSN: 0009-2940
    Keywords: Osmium(0) complexes ; Nitrosyl complexes ; Oxidative addition reactions ; Alkynyl(hydrido)osmium complexes ; Diynyl(hydrido)osmium complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The coordinatively unsaturated starting materials trans-[OsCl(NO)PiPr3)2] (2) and trans- [(sCl(NO)(PiPr2Ph)2] (3), for which a new one-pot synthesis is reported, react with isocyanides, SO2 and O2 to give the corresponding 1:1 adducts [OsCl(NO)(L)(P)(PiPr2R)2) (4-7). The corresponding methyleneosmium complex [OsCl(NO)(=CH2)(PiPr3)2] (9), on treatment with SO2 and HCl, affords the six-coordinate osmium(II) compounds [OsCl(NO)(K2(C,O)-CH2S(O)O)()iPr3)2] (10) and [OsCl2(NO)(CH3(PiPr3)2]2] (11), respectively. The reactions of 2 and 3 with HCl, I2, CH3I, CH2=CHBr, R'CO2H, PhSH, CH3OH, PhCOSH, and R'CHO lead by oxidative addition to the corresponding octahedral osmium(II) complexes [OsCl-(NO)(X)(Y)(PiPr2R)2] (12-24). The initially formed compound [OsHCl(NO){SC(=O)Ph}(PiPr3)2] (20a) rearranges smoothly to the more stable S-bonded isomer [OsHCl(NO){OC(=S)Ph}(PiPr3)2] (20b). Alkynyl(hydrid)- and diynyl(hydrido)-osmium(II) complexes 20-31 and 34, 35 are obtained from 2 or 3 and HC≡CCO2/sb〉Me, propargylic alcohols HC≡CCPh-(R')OH or the diyne HC≡CC≡CCPh2OH. The compounds [OsHCl(NO)[C≡CCPh(R')OH)(PiPr3)2] (30, 31) react with aqueous HCl in benzene to give the η1-allenylosmium(II) derivatives [OsCl2(NO)(η1-CH=C=C(Ph)R'](PiPr3)2] (32, 33). [OsHCl(NO)(C≡CC≡CCPh2OH)(PiPR3)2] (34) has been characterized by X-ray structural analysis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300409
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  • 261
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    Highly Substituted Cyclams: Stereoselective Synthesis and Coordination Properties (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 521-528 
    Details
    ISSN: 0009-2940
    Keywords: Macrocycles ; Hydrogenation ; Cyclam, binding constant ; N ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We report here a new synthetic route to highly-substituted tetraazamacrocycles. Raney nickel hydrogenation of macrocyclic phenylenediamine-acetylacetone condensation products gives cyclams in high yield with complexes all-cis stereoselectivity. The extensive C-substitution of the cyclam 2a changes its ligand properties markedly. The X-ray structure analyses of NiII, CuII, and ZnII complexes of 2a reveals a deviation of the metal ion coordination geometry from the usual square-planar arrangement. This may account for the differences in the redox properties of the NiII and CuII complexes of 2a leads to more positive oxidation and reduction potentials compared to the analogous unsubstituted cyclam complexes. While the binding constant between Zn(ClO4)2 and 2a is lower by a factor of 105 compared to cyclam, the subsequent binding of uridine to the zinc-cyclam complexes in methanol/water is slightly stronger in the case of 2a · Zn(ClO4)2].
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300412
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  • 262
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    Chemie polyfunktioneller Moleküle, 125Part 124: Ref. Synthese und Kristallstruktur von N,N,N′,N“,N-Pentamethyl-diethylentriamin-cokoordiniertem Kalium-bis(diphenylphosphanyl)amidHerrn Prof. Dr. Gerhard Herberich zum 60. Geburtstage gewidmet. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 141-144 
    Details
    ISSN: 0009-2940
    Keywords: Alkali metal organophosphanylamide ; Carbon-potassium bonding ; Phosphazane ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The metalation of bis(diphenylphosphanyl)amine [HN-(PPh2)2,1 with KOtBu at 95°C in toluene affords a pale yellow precipitate of potassium bis(diphenylphosphanyl)amide (3a). On addition of liquid N,N,N′,N“,N“-pentamethyldiethylenetriamine (PMDTA, 4) the precipitate dissolves in toluene at 115°C to give a yellow solution, from which yellow-green blocks of [(Ph2P)2NK·PMDTA] (3b) are obtained. X-ray analysis reveals that the coordination sphere of potassium consists of the chelating triamine ligand and [N(PPh2)2]- as N-donor as well as η1 and η2 C-donor with two phenyl fragments. No phosphorus coordination of [N(PPh2)2]- is observed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300124
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  • 263
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    Metal Complexes of Biologically Important Ligands, XCl. Introduction of Organometallic Fragments into α-Amino Acids by Reactions of α-Bromoglycine Derivatives with Anionic Organotransition-Metal CompoundsDedicated to Professor Victor Gutmann on the occasion of his 75th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 171-177 
    Details
    ISSN: 0009-2940
    Keywords: α-Bromoglycine derivatives ; Amino acids ; Iron ; Chromium ; Tungsten ; Transition-metal-labeled α-amino acids ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reactions of protected α-bromoglycine esters R1(O)CNHCH(Br)CO2R2 (R1=Ph, OCMe3; R2 =Me, tBu) with organometallic anions of acetylferrocene, CpFe(CO)(PPh3)-C(O)CH3, (OC)5M=C(OMe)CH3 (M=Cr, W), (OC)3Cr(η6-diphenylmethane), (OC)3Cr[η6-fluorene), (OC)3Cr(η6-dihydroanthracene) and of (OC)3Cr(-η6aniline) and (OC)3Cr(η6-o-toluidine) provide a method for the introduction of organometallic fragments into the side chains of α-amino acids.The complexes may be useful as markers for α-amino acids in peptides.The compound (OC))3Cr(η-o-C6H4(CH3)NHC-(H)(CO2Me)NHC(O)Ph was characterized by X-ray diffraction.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300206
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  • 264
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    Acetylene/Vinylidene Rearrangements of Fe(CO)2L2(silylacetylene) Complexes (L=Phosphorus Donor) (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 183-194 
    Details
    ISSN: 0009-2940
    Keywords: Iron ; Alkyne complexes ; Vinylidene complexes ; C-H oxidative addition ; Rearrangements ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of a mixture of Fe(CO)2(PEt3)2N2 (1a) and [Fe-(CO)2(PEt3)2]2N2 (1b) with acetylene leads to three complexes: Fe(CO)2(PEt3)2(π-HC≡CH) (2a), Fe(CO)2(PEt3)2(H)(C≡CH) (2b), and Fe(CO)2(PEt3)2=C=CH2 (2c). Upon chromatography on silylated silica gel the mixture of 2a-c is completely transformed into 2c. The analogous reaction of 1a, b or of Fe(CO)2[P(OiPr)3]2N2 (1d) with HC≡CSiMe3 affords the primary oxidative addition products Fe(CO)2L2(H)(C≡CSiMe3) [L = PEt3, 3a; L = P(OiPr)3, 3c]. The presence of a small amount of Al2O3 in hexane irreversibly converts 3a and 3c into the vinylidene compounds Fe(CO)2L2=C=C(H)SiMe3[L = PEt3, 4a; L = P(OiPr)3, 4c]. The chromatographic work-up of 4c additionally leads to the hydrolysis product Fe(CO)2[P(OiPr3)2]2=C=CH2 (2d). The reaction of the phosphite-substituted derivative Fe(CO)2[P(OMe)3]2I- (1c) with silylacetylene allows detection of the acetylene species Fe(CO)2 [ P(OMe)3]2 (HC ≡CSiMe3) (3b), as well as the acetylido hydrido derivative Fe(CO)2[P(OMe)3]2(H)(C=CSiMe3) (4b). In a slow subsequent process, or with promotion by Al2O3 in hexane, the vinylidene compound Fe(CO)2[P(OMe)3]2=C=C(H)SiMe3 is formed. 3b or 4b are hydrolyzed to Fe(CO)2[P(OMe)3]2=C=CH2 (5c) in the presence of SiO2. The reaction of disilylacetylene with 1a-d results in the formation of disilylvinylidene complexes Fe(CO)2L2=C=C(SiMe3)2 (L = PMe3, 7a; L=PEt3, 7b; L = PiPr3, 7c). An intermediate acetylene derivative could be isolated for L = PEt3 (6a) and spectroscopically detected for L = P(OMe)3 (6b), but could not be traced for L = P(OiPr)3. Further studies were devoted to the reactions of silyl diynes (Me3SiC≡CR, R = C≡CSiMe3, p-C6H4-C-CSiMe3) with 1a-c. In all cases the acetylene compounds Fe(CO)2L2(Me3-SiC≡CR) [L = PEt3, R = C≡CSiMe3, 8a; R = p-C6H4-C≡CSiMe3, 9a; L = P(OMe)3 R = CSiMe3, 8b; R = p-C6H4-C≡CSiMe3, 9b] were isolated, but only for 8b was an equilibrium process observed to form the corresponding vinylidene derivative Fe(CO)2[P(OMe)3]2=C=C(SiMe3)C-C-SiMe3 (10b). 10b hydrolyzes upon chromatography on silica gel to give Fe(CO)2[P(OMe)3]2=C=CH-C≡CSiMe3 (11b): Finally, the reaction of p-diethynylbenzene with 1a-c was explored. The acetylido hydrido species Fe(CO)2L2(H)C≡C-p-C6H4-C≡CH was isolated in the case of L = PEt3 (12a) and spectroscopically detected for L = P(OMe)3 (12b). 12b and 12a transform spontaneously and in the presence of Al2O3 in hexane, respectively, to the vinylidene complexes Fe(CO)2L2=C=C(H)R [R = C6H4-C≡CH, L = PEt3, 13a; L = P(OMe)3, 13b]. 6a, 7a, and 8a have been characterized by single-crystal X-ray diffraction studies.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300208
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    Heterobimetallic Sesquifulvalene and Hydrosesquifulvalenyl Manganese(I) Chromium(0) Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 225-230 
    Details
    ISSN: 0009-2940
    Keywords: Sesquifulvalene ; Heterobimetallic complexes ; Manganese ; Chromium ; Stille coupling ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of the heterobimetallic sesquifulvalene complex [(OC)3Mn(μ-η5:η7-C5H4-C7H6)Cr(CO)3]BF4 (2) is reported. [(2,4,6-Cycloheptatrien-1-yl)-η5-cyclopentadienyl]tricarbonylmanganese (3) reacts with (CH3CN)3Cr(CO)3 to give a mixture of endo- and exo-[(OC)3Mn(μ-η5:η6-C5H4C7H7)Cr(CO)3] (4a, b). Hydride abstraction from this mixture resulted in the formation of 2 in low yield. Alternatively, Stille coupling of 2-trimethylstannyl-1,3,5-cycloheptatriene (5) with (iodocyclopentadienyl)tricarbonylmanganese (6) gave [(1,3,5-cycloheptatrien-2-yl)-η5-cyclopentadienyl]tricarbonylmanganese (7). After treatment of 7 with (CH3CN)3Cr(CO)3, a mixture of two heterobimetallic complexes [(OC)3Mn(μ-η5:η6-C5H4-C7H7)Cr(CO)3] (8a, b) was isolated. In 8a, a bridging (1,3,5-cycloheptatrien-2-yl)cyclopentadienyl ligand was found, while 8b contains a (1,3,5-cycloheptatrien-1-yl)cyclopentadienyl ligand. The mixture 8a, b was converted quantitatively into 2 by reaction with triphenylcarbenium tetrafluoroborate. The X-ray crystal structures of 2, 4a, 4b and 8a are reported.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300214
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    Hydroxy- and Carboxy-Substituted Allylsilanes: A Simple and Stereoselective Method of Preparation (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 335-340 
    Details
    ISSN: 0009-2940
    Keywords: Allylsilanes ; Superbases ; Metalations ; Stereoselectivity ; Cyclizations ; Silicon ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: When treated with two equivalents of a butyllithium/potassium tert-butoxide mixture, terminal olefins carrying unprotected hydroxy or carboxy groups generate allylmetal intermediates which can be trapped with chlorotrimethylsilane to afford functionalized (Z)-2-alkenyltrimethylsilanes. One equivalent of the superbasic reagent suffices if the unsaturated alcohols are first protected as acetals before being subjected to the metalation/silylation/hydrolysis sequence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300306
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    Halogen/Metal vs. Hydrogen/Metal Exchange: General or Specific Site Selectivity as Exemplified in the Camphene Series (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 77-82 
    Details
    ISSN: 0009-2940
    Keywords: Monoterpenes ; Sesquiterpenes ; Stereoselectivity ; Alk-l-enyllithium(sodium) Metal exchange, halogen vs. hydrogen ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (Z)-(3,3-Dimethylbicyclo[2.2.1]hept-2-ylidene)methyllithium can be readily generated by treatment of (Z)-3-bromomethylene-2,2-dimethylbicyclo[2.2.1]heptane with tert-butyl-lithium. At -75°C, the organometallic intermediate is configurationally stable and reacts with a variety of electrophiles under stereochemical retention.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300112
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    Chemical Interconversions in the System TP*Zn/CO2/Alcohol [Tp* = Substituted Tris(pyrazolyl)borate]Dedicated to Prof. Walter Siebert on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 101-104 
    Details
    ISSN: 0009-2940
    Keywords: Zinc complexes ; Alkyl carbonate complexes ; CO2 fixation, reversible ; Catalysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The zinc hydroxide complexes Tp*Zn-OH with TpCum,Me = tris(3-cumenyl-5-methylpyrazolyl)borate and TptBu,Me = tris(3-tert-butyl-5-methylpyrazolyl)borate can be converted to the alkyl carbonate complexes Tp*Zn-OCOOR by reaction with dialkyl dicarbonates or with alcohol and CO2. An alternative formation reaction is the treatment of the pyrazolyl borate with zinc perchlorate and potassium carbonate in alcohol. The interconversion between TpCum,MeZn-OH and TpCum,MeZn-OCOOMe in methanol-containing solution can be repeatedly performed in both directions by bubbling either CO2 or N2 through the solution. The alkyl carbonate complexes show a variable sensitivity towards hydrolytic destruction with reformation of the hydroxide complexes. The complexes TptBu,MeZn-OCOOR (R = Me, Et) release CO2 under high vacuum to form the alkoxide complexes TptBu,Me-Zn-OR, which could not be obtained pure due to their extreme water sensitivity. Indirect evidence for their existence is also obtained by the reaction between TpCum,MeZn-OCOOMe and methyl iodide, forming TpCum,MeZn-I and dimethyl ether. The Zinc hydroxide complexes catalyse the formation of diethyl carbonate from ethanol and CO2.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300116
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    Electroactive Protecting Groups and Reaction Units, 6.Part 5: See ref. [21] - Titanium Enolate Radical Cations in Solution: Generation, Characterization, and Their Reactions (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 771-777 
    Details
    ISSN: 0009-2940
    Keywords: Titanium enolate ; Cyclic voltammetry ; EPR spectroscopy ; Radical ion ; Mesolytic bond cleavage ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For the first time titanium enolate radical cations were characterized in cyclic voltammetry experiments. Preparative one-electron oxidation of titanium enolates 1-3 led to the formation of benzofurans B1-B3 through mesolytic Ti-O bond fragmentation to α-carbonyl radical and a cationic titanocene(IV) species. With 1+·, the kinetics of the Ti-=O bond cleavage was investigated by fast scan cyclic voltammetry providing a first-order rate constant k1=850 ± 50 s-1 in acetonitrile at room temperature. The titanium enolate radical cations 1+·, 3+·, 4+· and 5%% were characterized by EPR spectroscopy, qualifying these species as electrophilic radicals. This feature can be exploited in C—C bond formation reactions such as the formal dimerization of 6 to 2,3-dimethyl-1,4-diphenylbuta-1,4-dione D6, which takes place on stage of the radical cation 6+·.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300616
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    Masthead (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300201
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    Matrix-Isolation of Iodine Superoxide and Iodine Dioxide (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 179-181 
    Details
    ISSN: 0009-2940
    Keywords: Matrix isolation ; Pyrolysis ; Photochemistry ; Iodine compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Flash pyrolysis of a gas mixture containing iodine, oxygen and argon yields the hitherto unknown iodine superoxide, which can be identified by its UV absorption (λ max= 254 nm) after trapping the pyrolysate at 12 K. Irradiation converts iodine superoxide into iodine dioxide, identified by its IR and UV spectra.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300207
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    Adjusting the Features of Active Metallocene Ziegler Systems fot Their Potential Use as Carbon-Carbon Coupling Catalysts in Organic Synthesis (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 201-207 
    Details
    ISSN: 0009-2940
    Keywords: Group-4 metallocenes ; Ziegler catalysts ; Cyclizations ; Sandwich complexes ; C-C coupling ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A variety of bent metallocene dichloride/methylalumoxane catalysts, derived from the zirconocene complexes 10, 12-18, have been employed in intramolecular olefin-coupling reactions yielding monomeric or dimeric products. This was achieved by using optimized reaction conditions employing low substrate concentrations (1.0-1.8 M) and rather long reaction times. Under these particular conditions, 1,5-hexadiene was cyclodimerized to give 1-methylene-3-(cyclopentylmethyl)cyclopentane (11). 1,6-Heptadiene was cleanly converted to methylenecyclohexane, and cis-1,2-divinylcyclopentane (19) and cis-1,2-divinylcylohenxane (22) were cyclized to yield 2-methylenebicyclo[3.3.0]octane (20) and 7-methylenebicyclo[4.3.0]nonane (23), respectively. In many cases, the cyclization products were accompanied by isomers originating from double-bond shift reactions that often occur rapidly at these catalyst systems under the specific reaction conditions chosen to keep the products in the monomeric regime.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300210
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    Polygold(1-adamantyl)ammonium Salts (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 221-223 
    Details
    ISSN: 0009-2940
    Keywords: Gold ; Polygoldammonium salts ; (1-Adamantyl)ammonium salts ; Trinuclear complex, X-ray structure of ; Tetranuclear complex ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of 1-adamantylamine with tris(triphenylphosphaneaurio)oxonium tetrafluoroborate results in the formation of the trinuclear adamantyltris(triphenylphosphaneaurio)ammonium tetrafluoroborate {C10H15[Au(PPh3)]3}+BF4-. The product can be further aurated by addition of equimolar amounts of triphenylphosphanegold(I) tetrafluoroborate to give the tetranuclear complex {C10H15N[Au(PPh3)]4}2+(BF4minus;)2. Both compounds have been fully characterized by analytical and spectroscopic data, and in the case of the trinuclear complex by a single crystal X-ray structure determination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300213
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    Contribution to the Chemistry of Boron, 235. Reactions of Prolinol with Borane-Tetrahydrofuran: Anomalous Dimerization of a 1,3,2-Oxazaborolidine (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 241-246 
    Details
    ISSN: 0009-2940
    Keywords: (2-Pyrrolidinylmethoxo)borane, anomalous dimer ; 5-Phenyl-3,4-dimethyl-1,3,2-oxazaborolidine, anomalous dimer ; Reaction intermediates ; Boron compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of (S)-prolinol (LH) with H3B · THF proceeds via [L2BH2〈]BH4, which decomposes with elimination of hydrogen at ca. -40°C to give the BH3 adduct of spirocyclic 7. On heating, 7 loses more H2 to give the “anomalous” dimerization product 11, which features a tetracoordinated B atom in a “tetrahedral” BN2O2 unit and another B atom in an N2BH2 environment. It is also shown that the product resulting from the reaction of pseudoephedrin with H3B·THF undergoes an analogous anomalous dimerization, affording product 8.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300217
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    1,4,7,10,13,16,19,22-Octaazacyclotetracosane-1,4,7,10,13,16,19,22-octaacetic Acid (H8OTEC) and 1,4,7,10,14,17,20,23-Octaazacyclohexacosane- 1,4,7,10,14,17,20,23-octaacetic Acid (H8OHEC): Synthesis and Characterization of Two Large Macrocyclic Polyamine Polycarboxylic Ligands and Some of Their Copper(II) and Lanthanide(III) Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 267-277 
    Details
    ISSN: 0009-2940
    Keywords: Macrocyclic ligands ; Lanthanides ; Copper ; Polyamines ; Polycarboxylic acids ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The optimized synthesis of two new macrocyclic polyamine polycarboxylic ligands, 1,4,7,10,14,17,20,23-octaazacyclohexacosane-1,4,7,10,14,17,20,23-octaacetic acid (H8OHEC) (10) and 1,4,7, 10,13,16,19,22-octaazacyclotetracosane-1,4,7,10, 13,16,19,22-octaacetic acid (H8OTEC) (12), is presented. The key step in the synthesis of both is the high yield carboxymethylation of the corresponding macrocyclic amines using tert-butyl bromoacetate followed by acidic hydrolysis of the acetate protecting groups. The molecular structures of the intermediates 1,4,7,10,14,17,20,23-octaazacyclohexacosane (OHEC-amine) (8), and octa-tert-butyl 1,4,7,10,13,16,19,22- octaazacyclotetracosane-1,4,7,10,13,16,19,22-octaacetate (OTEC-ester) (11) are determined by X-ray crystal structure analysis. OHEC-amine 8 reacts with 2 equiv. of CuSO4 yielding the dinuclear complex [Cu2(OHEC-amine)](SO4)2 (13). Complex 13 crystallizes with 16 molecules of water. 13 · 16 H2O contains two copper atoms, which are coordinated in a strongly distorted octahedral fashion by four nitrogen atoms, one oxygen atom from the sulfate dianion and one oxygen atom from a water molecule. The new ligands 10 and 12 are fully characterized by 1D- and 2D-NMR spectroscopy. Both ligands form dinuclear lanthanide(III) chelates (Ln=Y, Sm, Eu, Gd, Yb, Lu), which are stable and highly water soluble. With lanthanum(III) only mononuclear complexes are formed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300221
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    Masthead (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300301
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    Structure and Reactivity of the Metal Centers of Ribonucleotide Reductases (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 317-322 
    Details
    ISSN: 0009-2940
    Keywords: Ribonucleotide reductase ; Tyrosyl radical ; Adenosyl radical ; Glycyl radical ; Iron-sulfur cluster ; Cobalamin ; (S)-Adenosyl methionine ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The activation of the three classes of ribonucleotide reductases as free radical enzymes is reviewed. Class I uses O2 and a diferric μ-oxo center to generate a stable tyrosyl protein radical. Class II operates with adensoyl cobalamin as the precursor of a putative transient thiyl protein glycyl radical by the concerted forms an O2-sensitive protein glycyl radical by the concerted action of an iron-sulfur cluster and (S)-adensoyl methionine.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300303
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    The First Electron-Donor-Acceptor Paracyclophanes with Ferrocene NLO-Phores: Synthesis, Absorption and Electrochemical Properties (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 581-584 
    Details
    ISSN: 0009-2940
    Keywords: Vinylferrocene ; Pd-catalyzed twofold and fourfold couplings ; Electron-donor-acceptor[2.2]paracyclophanes ; Charge transfer ; Cyclic voltammetry ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: As potential nonlinear optical material. 12-nitro-4,7-bis(2-ferrocenylvinyl)[2.2]paracyclophane (1) and 12-nitro-4,5,7,8-tetrakis(2-ferrocenylvinyl)[2.2]paracyclophane(2) have been synthesized by pd-catalyzed coupling reactions of vinylferrocene with the precursor cyclophanes 9 and 13, respectively. The absorption and electrochemical properties of 1 and 2 are also described.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300508
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    C-H Bond Activation of Simple Alkenes with (C5H5)CO Fragments: Preparation, Molecular Structure, and Dynamical Behaviour of Tri- and Tetranuclear Cyclopentadienylcobalt Cluster complexes with μ-Cycloalkyne Ligands (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 593-603 
    Details
    ISSN: 0009-2940
    Keywords: C-H activation ; Alkyne complexes ; Cyclopentadienyl cobalt ; Fluxionality ; Hydrido complexes ; Clusters ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vicinal C-H bonds of the cycloalkenes CnH2n (n = 5-8) were activated upon treatment under mild conditions with reactive sources of the (C5H5)CO fragment. With [C5H5)CO(C2H4)2] (2a), the trinuclear cluster complexes [H2((C5H5)CO)3(μ3-C2(CH2)n-2)] (5a: n = 5; 5c: n = 5d: n = 8) were formed. Using the more reactive [(C5H5)2Co]/K, 5a-5dwere obtained, along with small amounts of the tetranuclear [{(C5H5)CO}4r{μ4-C2(CH2)n-2}] (8a-c: n = 5-7). X-ray structure analyses of 5c, d and 8b, c were performed. A μ-‖ (orμ3-η1:η2:η1) coordination of the cycloalkyne ligands was found in the trinuclear cluster complexes. The tetranuclear 8b, c had the cycloalkynes quadruply bridging (μ4-η1:η2:η2:η1_ a butterfly arrangement of the metal atoms. The acetylenic carbon-carbon bonds are considerably lengthened upon coordination [1.392(4), 1.398(3) å in 5c d; 1.464(8), 1.499(5) Å in 8b, c]. Three dynamic processes - alkyne “walk” on top of the CO3 triangle, μ2-hydride migration, and μ2/μ3-hydride exchange - are operational in the trinuclear 5a-d. Dynamic NMR data for 5a are consistent with a “windshield-wiper” mechanism for the alkyne migration. Hydride exchange is associated with a higher energy barrier, and is probably and independent dynamic process.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300510
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    “Potassium Potassates” Based on Dihydrotriazinide Ligands: Syntheses, Crystal Structures, and Comparison with Other Alkali Metal Dihydrotriazinide Compounds (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 621-631 
    Details
    ISSN: 0009-2940
    Keywords: Alkali metals ; ate compounds ; Dihydrotriazine ; Potassium ; N ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of dihydro-s-triazinidopotassium complexes have been synthesised and structurally characterised by X-ray diffraction. Two of them, the sesqui-pyridine solvate 2 and the mono-THF solvate 3, can be classified in formal terms as “potassium potassates” in conforming to the structural pattern established previously for the sesqui-THF solvate 1, the first reported ate of this type. Formally complex [(R2K)-] anions are linked to K+ cations in polymeric, zig-zag chain arrangements. Solvate 3 also possesses a unique RK coordination as a direct result of having fewer solvent ligands. DMSO analogue 4 deviates from this uniformity in adopting a centrosymmetric, dimeric (OK)2 ring structure featuring both terminal and bridging DMSO ligands. The dihydro-s-triazinidosodium tris(THF) solvate 5 is found to be a monomer. For comparative purposes, the metal-free, parent triazine molecule 6 has also been subjected to an X-ray crystallographic study: it displays a 1,2-dihydro ring setup as opposed to the 1,4-dihydro alternative existing in the metallo examples. Triazine 6 is also found to form a N-H…Br bridge in the dimeric structure of the lithium bromide bis (THF) solvate 7, a suspected hydrolysis product from the reaction of dihydro-s-triazinidolithium 8 and magnesium bromide bis(ether) adduct.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300513
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    Models for Vanadate-Dependent Haloperoxidases: Vanadium Complexes with O4N-Donor SetsDedicated to Prof. Dr. R. Nast on the occasion of his 85th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 651-657 
    Details
    ISSN: 0009-2940
    Keywords: Vanadium ; Haloperoxidase ; Schiff bases ; Diethanolamine ; Water ligation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of vanadyl sulfate with the Schiff base H2L1 derived from o-vanillin and glycine leads to [VIVO(H2O)L1 (1), treatment of which with acetyl chloride affords cis-[VIVCl2L1] (2). Reaction of [VO(acac)2] with the Schiff base H2L2 derived from o-hydroxynaphthaldehyde and o-hydroxyaniline under aerobic conditions yields [{VVO(L2)}2μ-O] (3), which undergoes methanolysis in excess methanol to form [VVO(MeOH)(OMe)L2] (5a). Complex 5a is also obtained via [VVOCl(L2)] (4) and MeOH. On treatment of 3 with an equimolar amount of ethanol, [VVOCl(L2)] (4) and MeOH. On treatment of 3 with an equimolar amount of ethanol. [VVO(OEt)L2] (5b) is obtained. With the chiral tertiary bis(ethanol)amine (S)- or (R)-(HOCH2CH2)2NCH(Ph)Me, H2L3, [VO(acac)2] loses only one acetylacetonate (1-) ligand, and the complexes (S)- and (R)-[VVO(acac)L3] (6a) are formed. As is evident for the corresponding reaction with (HOCH2CH2)2NPh, H2L4, which affords [VVO(acac)L4 (6b), the substitution is a second-order process (rate constant 0.013 M-1 h-1). 5a…MeOH, 5b, (R)-6a, and (S)-6a have been structurally characterized by single crystal X-ray diffraction analysis. The molecular connectivities have also been established for 1-H2O. All of the structurally characterized complexes contain an O*O3N donor set (O* denotes a doubly-bonded oxo group) and thus model the coordination environment of the active site in vanadate-dependent haloperoxidases. This model character is particularly pronounced in 5b, the coordination geometry of which is half-way to trigonal-bipyramidal. 5a and 6a contain, in addition to the O*O3N set, a labile V-O or V-N bond, respectively, which may mimic substrate binding to the active centre. 6a is also of relevance to the enantioselective peroxide oxidation of sulfides to sulfoxides by catalyst systems containing vanadium and H2L3.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300517
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    Carbene Structure of Stable Acyl (Formyl) Anion EquivalentsDedicated tp Professor Dr. Peter Welzel on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1201-1212 
    Details
    ISSN: 0009-2940
    Keywords: Acyllithium equivalents ; Lithium ; Carbenes ; Structure elucidation ; Ab initio calculations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 3-Lithiated 4-tert-butyl-imidazol-2-ylidene, 3-lithiated 4-tert-butyl-thiazol-2-ylidene, and the ZnBr species of the latter, are shown to be stable carbenes by X-ray crystal structure determination. The crystal data are confirmed by 13C-NMR investigations in solution and quantum-chemical calculations. The exceptional stability of the acyl anion equivalents is due to the p(.) stabilization of the carbene carbon atoms by the adjacent amino (thio) substituents, as is also the case in the structurally related stable carbenes, which have recently been isolated for the first time by A. J.Arduengo III et al., and in stable nitrenium ions, as found by our group.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300907
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    The Chemistry of Metallacyclic Alkenylcarbene Complexes, 8Part 7: Ref. Chelated Allyl-Ironcarbene Complexes with a Centrally Tethered π-Ligand-Synthesis and Reactions with Nucleophiles (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 863-869 
    Details
    ISSN: 0009-2940
    Keywords: Carbene complexes ; Iron ; Alkene complexes ; Carbamates ; Trimethylenemethane complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The title complexes 8 and 9 are easily prepared in two or three steps from iron carbonyls and isobutene diol 5 by Meerwein alkylation of the intermediate acyl complexes 6 and 7. With carbon and heteroatom nucleophiles like enolates and triphenylphosphane they form either stable 4-substituted alkene-carbene complexes 10 and 11, or substituted trimethylenemethane tricarbonyliron complexes like 12. Oxidation with H2O2/NaOH both of the alkene-carbene complexes 11 and of the less stable β-oxo-substituted trimethylene-methane complexes 13, as obtained from reaction of 8 with lithium enolates, yields the corresponding substituted allyl carbamates 15 or the allyl alcohols 14, which are formally bis- and monosubstituted derivatives, respectively, of the starting isobutene diol.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300709
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    Benzil Derivatives as Trapping Reagents for the Monomeric Alkylindium(i) Compound in-c(SiMe3)3 (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1269-1272 
    Details
    ISSN: 0009-2940
    Keywords: Indium ; Clusters ; Low-valent compounds ; Trapping reactions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The tetrahedral cluster compound tetrakis[[Tris(trimethylsilyl)methyl]indium(I)] 91) reacts in boiling n-hexane with benzil derivatives (p-X-C6H4)C(O)(p-X-C6H4) (X = H, OMe, Br), to yield the 1,4-cycloadditon products of the monomeric alkylindium(I), In-C(SiMe3)3, in which the In atoms are coordinated by a chelating enediolato ligand, to form a five-membered InO2C2 heterocycle. As shown by two crystal structure determinations (X = H, OMe), the products are dimeric in the solid state, with a four-membered In2O2 heterocycle in the molecular center and both C(SiMe3)3 groups, as well as both enediolato substitutents in a cis arrangement.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300915
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    Compounds of Germanium and Tin, 2lPart 20: Ref.[1]. A Tetraaryldigermene with a Short Germanium-Germanium Double Bond and a Nearly Planar Environment of Both Germanium AtomsDedicated to Professor Hans Bürger on the occasion of his 6oth birthday (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 735-738 
    Details
    ISSN: 0009-2940
    Keywords: Germanium ; Digermenes ; Tin ; Germylenes ; Stannylenes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Treatment of GeCl2 · dioxane with the Grignard reagent RMgBr (R=2-tBu-4,5,6-Me3C6H) furnishes the tetraaryldigermene R2Ge=GeR2 (8). X-ray structure-analysis of 8 reveals a short Ge=Ge double bond, a nearly planar environment of both germanium atoms and extremely widened C—Ge—C angles of 128°. In solution, 8 dissociates into two germylene molecules R2Ge, which can be trapped with oxygen or by [4+1] cycloaddition reactions with 1,4-dihetero-1,3-dienes. A similar cycloadduct of a stannylene wa obtained by thermolysis of (R′2Sn)3 (R′=2,4,6-iPr3C6H2), in the presence of a 1,4-diazabutadiene and characterized by an X-ray structure-analysis.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300610
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    Chiral Arene Ruthenium Complexes, 2 A Diastereoselective Route to [η6-Benzyl Alcohol)(COD)Ru] Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1321-1325 
    Details
    ISSN: 0009-2940
    Keywords: Arene Complexes ; Ruthenium ; Diastereoselective ; Reduction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two preparative routes are reported that give access to the racemic series of planar chiral [(arene)(COD)Ru] derivatives containing η6-bonded o-tolyl ketone or aldehyde arene units. The ketone and aldehyde functions of these have subsequently been reduced by nBuLi and PhLi, respectively. Hydrolysis converts the initially formed lithium salts into diastereomeric benzyl alcohol complexes lithium salts into diastereomeric benzyl alcohol complexes in high yields. The formation of the new stereogenic centre is diastereoselective (88% de) for the aldehyde and diastereospecific for the ketone (de 〉 99%). Due to a sterically overcrowded situation, the rotation of the chiral side chain of [(COD) (η6-o-tolyl-tert-butylphenylmethanol) Ru] (7) is hindered, as is the rotation of the phenyl and tert-butyl substituents. As a consequence, the hydroxyl group is fixed at a position close to the metal both in solution and in the solid state.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300923
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    Organo-Substituted 1,2-Dihydro-1,2,5-Disilaborepines (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1349-1352 
    Details
    ISSN: 0009-2940
    Keywords: Heterocycles ; 1,1-Organoboration ; Disilanes ; 1- Alkynylsilanes ; NMR spectroscopy ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,2-Di-1-propynyl-tetramethyldisilan (1) reacts with triorganoboranes R3B [R = Et (2a), CH2Ph (2c), 2-thienyl (2d)], 9-ethyl-9-borabicyclo[3.3.1]nonane (3), and diethyl(N-pyrrolyl)borane (4) by twofold 1,1-organoboration to give selectively the respective organo-substituted 1,2-dihydro-1,2,5-disilaborepines 5a-d,6, and 7 in high yields. The compounds 5-7 were characterized by 1H-, 11B-, 13C-, and 29Si-NMR spectroscopy in solution. The molecular structures of the distance 1 and of the heterocycle 5c were determined by X-ray structure analysis.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300928
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    Complexes of Early Transition Metal Alkoxides: Molecular Structure of Ti(OiPr)4[OPb4(tBuN)3] (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1361-1363 
    Details
    ISSN: 0009-2940
    Keywords: Titanium ; Lead ; Alkoxides ; Amides ; Mixed-Metal species ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction between Ti(OiPr)4 and [Pb(NtBu)2] (1) in refluxing THF afforded the complex Ti(OiPr)4OPb4(NtBu)3] (2) which has been characterized by X-ray diffraction studies and by 1H- and 13C-NMR spectroscopy. Titanium is five coordinate and it displays a trigonal bipyramidal stereochemistry with the pb4(tBuN)3O cage ligand bonded to titanium through the oxygen atom and occupying an apical position. The origin of the cubane lead ligand is discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300930
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    Cobalt-Catalyzed Selective Oxidation of the Tritertiary Phosphane Triphos with Molecular OxygenDedicated to Professor H. Bärnighausen on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1393-1403 
    Details
    ISSN: 0009-2940
    Keywords: Tripod ligands ; Phosphane oxides ; Cobalt ; Oxidation ; Catalysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reactivity of complexes of triphos [CH3C(CH2PPh2)3] and CoCl2 towards dioxygen has been investigated. Reaction of the pseudo-tetrahedral complex (η2-triphos)CoCl2 (1) with dioxygen yields after work-up the mixed phosphane/phosphane oxide ligands triphosO and triphosO2. The novel ligand triphosO2 can be obtained in quantitative yield using catalytic amounts of 1. In order to gain some insight into the catalytic dioxygen activation reaction, experiments with various triphos/Co/Cl species, in different solvents and at several concentrations have been carried out. A mechanism involving two separate reaction pathways is proposed. Complexes of triphosO and triphosO2 with CoCl2, [η2-(P, P)-triphosO]CoCl2 (4), and [η2-(P, O)-triphosO2]CoCl2 (5), which are present as intermediates in the oxygenation reaction, have been isolated and fully characterized including X-ray structural analyses.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971301007
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    Tetramethylguanidine and Benzophenoneimine as Ligands in Gold Chemistry (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1417-1422 
    Details
    ISSN: 0009-2940
    Keywords: Gold ; N ligands ; Gold(I) complexes ; (Imine)gold(I) complexes ; Guanidines ; Ketimines ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (Tetramethylguanidine)gold(I) chloride (1) and bromide (2) are readily prepared in high yield from (Me2N)2C=NH and [AuCl(Me2S)] or [AuBr(tht) (tht = tetrahydrothiophene), repectively. NMR spectra of chloroform solutions of the two products indicate equilibria of the type 2 LAuX = L2Au+AuX2-. The cationic complex [Au(NH=C(NMe2)2)(PPh3)]+ is obtained as the triflate salt 3 from tetramethylguanidine and [Au(PPh3)]+O3SCF3-. In solution at low temperature (-60°C), this compound adopts a rigid structure whereby the NMe2 groups are rendered non-equivalent, but at ambient temperature there is coalescence of the NMe2 signals in the 1H- and 13C-NMR spectra. The related benzophenoneimine complex [Au{NH=CPh2}(PPh3)]+BF4- (4), which was synthesized as a reference3 compound, exhibits similar behaviour. In solution at low temperature (-60°C) the two phenyl rings of the ligand are diastereotopic. In contrast, the triisopropylphosphane derivative [Au[NH=CPh2](PiPr3)]+BF4- (5) is rigid on the NMR time scale, even at 25°C. Thbe solid-state structures of 2, 3, 4, and 5 have been determined by single-crystal X-ray diffraction. Compound 2 crystallizes in the ionic form with discrete Au … Au bonded ion pairs [Au[NH=C(NMe2)2]2]+ [AuBr2]- [Au … Au 3.1413(8) Å]. The cations of 3, 4, and 5 show the [Au(PPh3)]+ units N-coordinated to the imino groups, with the nitrogen atoms in a trigonal-planar configuration.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971301010
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    Switch from Palladium-Catalyzed Cycloisomerization/Dimerization of Terminal Allenyl Ketones to Preferential Formation of Monomers by a 5-Palladatricyclo[4.1.0.02,4]heptane Catalyst: Synthesis of Furans from Substrates Incompatible with the Commonly Used Silver Catalysts (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1449-1456 
    Details
    ISSN: 0009-2940
    Keywords: Alkynes ; Allenes ; Furans ; Palladium ; Catalysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: By making the choice of either PDCl2(MeCN)2 or PTH rac-4 as catalyst, the allenyl ketones 1 could be preferentially cycloisomerized/dimerized to either 2,4-disubstituted furans 3 or preferentially cycloisomerized to the monosubstituted furans 2. Since the PTH catalyst tolerates functional groups like terminal alkynes, α-halogen ketones, and alkyl halides that inhibit the silver catalysis, the latter method is an important extension of Marshall's Ag1-catalyzed isomerization of 1 to 2. Some of these latter reactions also showed exciting chemoselectivities, e.g. with allenyl ketones, such as 1c and 1d, which also also possess a 1,6-enyne substructure, no enynecyclization was observed. This is also the first reported example of catalysis by a PTH.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19971301015
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    Synthesis, Structure, and Dynamic Behavior of (μ-Aldimido)(μ-η1: η2-alkyne)- biszirconocene Cation Complexes That Contain Planar-Tetracoordinate Carbon (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1069-1077 
    Details
    ISSN: 0009-2940
    Keywords: Planar-tetracoordinate carbon ; Dynamic organometallic systems, μ-alkyne complexes ; π-Agostic systems ; Zirconium ; Metallocenes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The benzonitrile hydrozirconation product Cp2ZrCl(N—CHPh) 8 was treated with propynyl lithium to yield the (propynyl)(benzaldimido)ZrCp; complex 9. Subsequent treatment with trityl tetraphenylborate generated [Cp2Zr(C—C—CH3)-BPh-4] that instantaneously added to 9 to eventually form the (μ-aldimido)(μ-η1:η2-hexadiyne)ZrCp2 cation 11. The X-ray crystal structure analysis showed that 11 contains a planar-tetracoordinate carbon atom that is stabilized by forming a three-center-two-electron bond with the two adjacent metal atoms. Similarly, complex 9 reacted with [Cp2Zr(CH3)+CH3B(C6F5)3 1 to yield the planar-tetracoordinate carbon containing (μ-aldimido)(μ-η1:η2-2-butyne) Cp; cation 12. Both complexes 11 and 12 exhibit dynamic NMR spectra due to their rapid reorganization of the dimetallabicyclic frameworks (ΔG* = 10 kcal mol-1) in addition to an anchimerically assisted C—N bond rotation (ΔG* =15 kcal mol-1).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300808
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    Isolation and Characterization of a Porphinatomanganese(IV) Complex from the Reaction of Dichloro Monoxide with 5,10,15,20-Tetrakis-(2,6-dichloropheny)porphinatomanganese(III) Chloride [Mn(EDCPP)CI] (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1099-1103 
    Details
    ISSN: 0009-2940
    Keywords: Porphyrinatomanganese(IV) ; Monooxygenase model ; Dichloro monoxide ; Catalytic alkene epoxidation ; Catalytic alkane oxygenation ; Catalytic alkane chlorination ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The isolation at -78°C and characterization of the novel crystalline reactive porphinatomanganese(IV) complex Mn-(TDCPP)(OCl)2 (5) is described. 5 is compared with the porphinatomanganese(IV) complexes Mn(TDCPP)(C6H5IOCl)2 (2), Mn(TDCPP)(C6F510C1)CI (3) and Mn(TDCPP)(OCH3)2, (4). The stoichiometric reaction of 5 with triphenylphosphane yields 2.5 equivalents of triphenylphosphane oxide and 1.0 equivalent of Mn(TDCPP)Cl (1). Complex 5 epoxidizes stilbene, and oxygenates and chlorinates cyclohexane.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19971300811
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    Reactive E=C [p-p] π Systems, 46Part 45: Ref. Syntheses and X-ray Crystal-Structure Analyses of Trifluoromethyl-Substituted Ketiminodiselanes, Selenoamides and SelenoacrylamidesDedicated to Professor Peter Sartori on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 913-922 
    Details
    ISSN: 0009-2940
    Keywords: Selenium ; Fluorine ; Amides ; Cleavage reactions ; Cycloadditions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bis(trifluoromethylketiminoalkyl)diselanes [SeC(=NR)CF3]2 (6) [R = Me (a), iPr (b), tBu (c)] have been prepared in high yields (55-70%) by reaction of the diselane (SeC2F5)2 (2) with RNH2. However, the analogous reaction of 2 with secondary amines, R2NH, results in the cleavage of the Se-Se bond and leads to the N,N-dialkyl-2,2,2-trifluoroselenoacetamides Se=C(NR2)CF3 (7) [R = Me (a), iPr (b)]. Cleavage of 6a-6c with Me3SnH affords the selenoamides Se=C(NHR)CF3 (9) and the corresponding stannylselanes Me3SnSeC(=NR)CF3 (10) [R = Me(a), iPr (b), tBu (c)]. Selenoamides 7 and 9 can also be prepared from pentafluoroethylselenol HSeC2F5 (3), Se=C(F)CF3, (1) or its polymer [SeC(F)CF3]n (4) and primary or secondary amines. N,N-dialkyl-2-methyl-3-fluoro-4,4,4-trifluoroselenoacrylamides Se=C(NR2)C(Me)=C(F)CF3[R = Et (13a), iPr (13b)] are prepared in moderate yields under mild conditions by treating either trifluoromethylselenocarbonyl fluoride (1) or its polymer [SeC(F)CF3]n with 1-dialkylamino-1-propynes. The reaction proceeds by [2 + 2] cycloaddition and stereospecific electrocyclic ring-opening, yielding, with respect to the resulting C=C double bond, the E isomer as the only product. The molecular structures of 7b, 9a and 13b show the typical features of selenoamides with C(Se)-N bond shortening and C-Se bond elongation due to π interaction of the N lone pair with the C=Se double bond. The observed perpendicular orientation of the selenoamide and the alkene units of 13b prevents π delocalization.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19971300717
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    Contribution to the Chemistry of Boron, 238Part 237: See ref. Synthesis and Assembly Mechanism for Spirocyclic Cage Compounds Containing, B, P and Si Atoms (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 933-937 
    Details
    ISSN: 0009-2940
    Keywords: Boron ; Phosphorus ; Spiro compounds ; Cage compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of 1-lithio · DME-2,4-bis(dialkylamino)-l,3,2,4-diphosphadiboretanes (1a, 1b) with SiCl4 followed by dehydrohalogenation with tBuLi produce spirocyclic compounds [(R2NB)2P2]2Si (2a, 2b). The compounds have been characterized by spectroscopic methods and X-ray crystallography. The assembly process has also been followed and one intermediate species [(iPr2NB)2P2][(iPr2NB)P(H)(iPr2NB)P]SiCl (3) has been isolated and fully characterized.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300719
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    Complex Catalysis, XLIXPart XLVIII: R. Taube, H. Windisch, S. Maiwald, H. Helming, H. Schumann, J. Organomet. Chem. 1996,513, 49-61 On the Coordination of Olefins and Secondary Amines at the Cationic [2,6-Bis(diphenylphosphanylmethyl)pyridine]rhodium(I) Fragment [Rh(PNP)]+ - Synthesis and Characterization of [Rh(PNP)(L)]X (L = Ethylene, Styrene, HNR2; X = BF4, PF6, CF3SO3)Dedicated to Prof. Dr. Wolfgang Beck on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 939-945 
    Details
    ISSN: 0009-2940
    Keywords: Rhodium ; Cations ; Tridentate ligand ; Alkene complexes ; P Ligands ; N ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The cationic rhodium(1) complexes [Rh(PNP)(C2H4)]X; X = BF4 (1a), PF6 (1b), CF3SO3 (1c ) were prepared by addition of the tridentate ligand 2,6-bis(diphenylphosphanylmethyl)pyridine (PNP) to a solution of [Rh(C2H4)2(solv)2]X (solv = acetone or THF) under ethylene. The complexes were characterized by IR and 1H-, 13C-, and 31P-NMR spectroscopy. The coordination of two ethylene molecules at the [Rh(PNP)]+ fragment could be detected by dynamic proton resonance of a solution of 1a under free ethylene. The styrene complex [Rh(PNP)(styrene)]BF4 (4) was obtained by substitution of the ethylene from 1a with an excess of styrene. The π coordination of C2H4 and styrene in 1a and 4 respectively was confirmed by X-ray crystal structure analysis. The olefin complexes react with an excess of the secondary amine to give the corresponding amine complexes [Rh(PNP)(HNR2)]X; HNR2 = piperidine (5), HNMe2 (6 ), HNEt2 (7). Conversly, the amine could be released from the amine complexes with an excess of ethylene at low temperature by the formation of the ethylene complex 1.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300720
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  • 297
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    Photochemical Reactions of a Binuclear Naphthalene-Manganese Complex with 2-Butyne (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1197-1200 
    Details
    ISSN: 0009-2940
    Keywords: Binuclear complexes ; Manganese ; Napthalene complexes ; Dienyl complexes ; Alkynes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pentacarbonyl(μ-.4:6-1,4-dimethylnapthalene)dimanganese-(Mn-Mn) (1), upon UV irradiation at 193 K in the presence of 2-butyne (2), yields tetracarbonyl(μ-.2:2-2-butyne)(μ-1,2,3,4-.:1,4,4a,8a-.-1,4-dimethylnaphthalene)dimanganese (3) and tricarbonyl(4a,6,7,8,8a-.-5-hydro-1,4-dimethylnapthalene)-manganese (4). The tetracarbonyl complex 3 rearranges in solution at room temperature to give tetracarbonyl(μ-.2:2-2-butyne)(μ-4a,5,8,8a-.:5,6,7,8-.-1,4-dimethylnaphthalene)-dimanganese (5). The complexes 3 and 5 were characterised by IR and NMR spectroscopy, and by mass spectrometry, and complex 4 by IR and NMR spectroscopy. The molecular structures of 3 and 4 were determined by single-crystal X-ray diffraction analyses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300906
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  • 298
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    Synthesis Structure and Photoluminescence of 1,2-Disila-acenaphthene Si2C10H10 and 1,2-Diaryldisilane Reference Compounds (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1671-1676 
    Details
    ISSN: 0009-2940
    Keywords: Silicon ; Disilanes ; Diaryldisilanes ; Disilanyl-arenes ; 1,2-Disila-acenaphthene ; Fluorescence spectroscopy ; UV/Vis spectroscopy ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For the synthesis of the diaryldisilanes Ar-SiH2SiH2-Ar (1a, Ar = phenyl; 1b, Ar = p-tolyl 1c, Ar = mesityl; 1d, Ar = p-anisyl) two convenient preparative routes are reported. The crystal structures of 1c and 1d have been determined in X-ray diffraction studies; the disilanes have a staggered transconformation with a crystallographically imposed center of inversion. For 1a-d no photoluminescence phenomena can be observed. 1,2-Disila-acenaphthene (2) is synthesized in acceptable yield by treatment of 1,8-dilithionaphthalene with 1 equivalent of 1,2-bis[((trifluoromethyl)sulfonyl)oxy]disilane Tf-SiH2SiH2-Tf. The crystal structure of 2 has been determined by X-ray diffraction. The molecule has no crystallographically imposed symmetry but closely follows the symmetry elements of points group C2v. Solutions of 2 exhibit intense fluorescence in the near UV region at room temperature. The fluorescence spectra are discussed in comparison with data on acenaphthene and naphthalene.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971301119
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  • 299
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    Dichotomy in the Reactivity of Trivalent Phosphorus Compounds Z3P (Z = Ph, nBu, OR) Observed in the Photoreaction with a Ruthenium Complex (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1699-1707 
    Details
    ISSN: 0009-2940
    Keywords: Trivalent phosphorus ; Ruthenium ; Photolysis ; Electron transfer ; Ligand exchange ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Solutions of tris(2,2′-bipyridyl)ruthenium(II) dichloride (Ru2+) and various types of trivalent phosphorus compounds Z3P (Z = Ph, n-Bu, OR; 1) in methanol have been photolyzed with visible light at 20 °C under an argon atmosphere, resulting in the oxidation of 1 to the corresponding pentavalent oxo compounds Z3P=O and ligand exchange of Ru2+ with 1. The former process takes place via single-electron transfer (SET) from 1 to Ru2+ in the photoexcited state, Ru2+*, which generates the radical cation intermediate Z3P.+ from 1. The latter results from nucleophilic attack of 1 upon Ru2+*. The results show that 1 can act either as an electron donor or as a nucleophile toward Ru2+*. The rate constants for both processes are estimated. An excellent linear correlation is found between the logarithm of the SET rate and the oxidation potential for both the aromatic and aliphatic trivalent phosphorus comparison with SET quenching by amines. On the other hand, a dualparameter correlation analysis shows that the ligand exchange is regulated by both steric and electronic factor in 1.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971301122
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  • 300
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    A Monomeric Bis(arena)lead(II) Complex with a Plumbocene-like Bent Sandwich Structural Unit  -  Structure of [Pb(1,2-C6H4Me2)2(AlCl4)2Dedicated to Professor C. G. Kreiter on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1731-1732 
    Details
    ISSN: 0009-2940
    Keywords: Lead ; Tetrachloroaluminate ; Arenes ; o-Xylene ; Bis(arene) Complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bis(o-xylene)lead(II) bis(tetrachloroaluminate), obtained from lead(II) chloride and aluminium trichloride in o-xylene, has been shown by X-ray crystallography to be a mononuclear lead complex with point group symmetry C2 The two aromatic ligands are arranged similarly to those in monomeric plumbocene. The coordination sphere is completed by two bidentate AlCl4-ions. The lead center uses about a quarter of its bonding capability for each of the four ligands
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971301204
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