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  • Inorganic Chemistry  (83.665)
  • Atomic, Molecular and Optical Physics  (6.266)
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  • 101
    Digitale Medien
    Digitale Medien
    Pyrazolate-Based Oligonuclear Copper and Silver Complexes with N/S Coordination SpheresDedicated to Prof. Dr. Gottfried Huttner on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1441-1447 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Pyrazolate complexes ; Bridging ligands ; Copper ; Silver ; N,S-Donor Ligands ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A series of pyrazole-based potential ligands bearing thioether substituents in 3- and 5-positions of the heterocycle was synthesized [3,5-bis(RSCH2)-pyzH R=Ph (1aH), PhCH2 (1bH), iPr (1cH), tBu (1dH)]. These ligands afford oligonuclear Cu1 and Ag1 coordination compounds [LCu]x (2a-c, L = 1a - c) and [LAg]x (3a-d, L = 1a-d), respectively. The single crystal X-ray analysis of 3c shows the presence of trimeric planar arrays of N,N′-bridging pyrazolates and linear coordinated silver ions, with each two of the trinuclear moieties being linked by two unsupported short intermolecular Ag…Ag contacts [3.041(1) Å]. Molecular-weight determinations for 2a (THF) and 3c (toluene) indicate that hexanuclear entities are preserved in solution. Starting from 1bH the CuII complex [(1b)2Cu2](BF4)2 (4) was synthesized. According to an X-ray crystal structure analysis it consists of dinuclear molecules with two bridging pyrazolates, distorted square planar N2S2 coordination spheres for Cu11 and an axially bridging tetrafluoroborate. Magnetic susceptibility data reveal an antiferromagnetic exchange (J = -206 cm-1) that is among the highest found for doubly pyrazolate bridged dicopper(II) complexes, which is rationalized on the basis of the rather symmetric dinuclear core of 4. The irreversibility of the electrochemical reduction and oxidation processes for the CuII and CuI compounds, respectively, is explained by the inability of the respective coordination framework to adapt to different geometric preferences.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301014
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  • 102
    Digitale Medien
    Digitale Medien
    Hydrocarbon-Bridged Metal Complexes, XLI. Addition of Aniline Tricarbonyl Chromium Complexes to the Cyclohexadienyl Ligand of (μ5-C6H7)M(CO)3+ (M = Fe, Ru)Dedicated to Professor Hanns-Peter Boehm on the occasion of his 70th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1475-1477 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Iron ; Ruthenium ; Chromium ; Carbonyl complexes ; N-(2,4-Cyclohexadienyl)aniline ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The addition of aniline tricarbonyl chromium complexes (η6-C6H4(R)NHR1)Cr(CO)3 (R=H, CH3; R1=H, CH3) to [(n5-C6H7)M(CO)3]+ (M=Fe, Ru) gives the heterobimetallic ligand-bridged complexes (OC)3Cr(n6-C6H4(R)N(R1)C6H7-n4)M(CO)3. The structure of (OC)3Cr(n6-C6H4(CH3)N(H)-C6H7-n4)Ru(CO)3 has been determined by X-ray diffraction.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301019
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  • 103
    Digitale Medien
    Digitale Medien
    New Phosphorus Heterocycles by Rearrangement of a [1,4-Bis(trimethylsilyl) η8-cyclooctatetraene-1,3,5-triphospha-7-hafnanorbornadiene ComplexDedicated to Professor C. G Kreiter on the occasion o f his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1491-1494 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Phosphorus heterocycles ; Phosphaalkynes ; Triphospha Dewar benzenes ; Triphosphacyclobutadiene ; 1,4-Bis(trimethylsilyl)-η8-cyclooctatrienehafnium complexes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: [1,4-Bis(trimethylsilyl)-n8-cyclooctatetraene]-2, 4, 6-tri-tert-butyl-1, 3, 5-triphospha-7-hafnanorbornadiene (3) rearranges nearly quantitatively to the corresponding 3,5,6-tri-tert-butyl-1,2,4-triphospha-7-hafnanorbornadiene complex 5 upon heating at 70°C. Treatment of complex 5 with trimethylphosphane at 50°C induces the displacement of di-tert-butylacetylene to give the new (n4-triphosphacyclobutadiene)hafnium complex 7, the crystalstructure of which has been determined by X-ray analysis. From complex 5 3,5,6,-tri-tert-butyl-1,2,4-triphospha Dewar benzene (6) can be synthesized by a redox reaction with hexachloroethane.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301022
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  • 104
    Digitale Medien
    Digitale Medien
    Dirhenium Complexes with S2CPR3 Bridges Donating Four and Eight Electrons  -  X-ray Structures of [Re2(CO)8{μ-η1;η1-S2CPCy3}] and {Re2(CO)6{μ-η3;-S2CPCy3}] and [Re2(CO)6{μ-η2; η3-S2CPCy3}] (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1507-1511 
    Details
    ISSN: 0009-2940
    Schlagwort(e): 1,1-Dithiolate ; Rhenium ; Carbonyl complexes ; Bridging ligands ; Bimetallic complexes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reaction of fac-[Re(CO)3(S2CPR3)Br] with [Rc(CO)5]- affords the dinuclear octacarbonyl compounds [Re2(CO)8(μ-S2CPR3)] (3a—b), which have been isolated and characterized by spectroscopic methods. An X-ray crystal-structure determination of the derivative 3a (R=Cy) shows that the S2CPCY3 ligand acts as an η1(S);η1(S′) bridge donating two electrons to each metal atom of a symmetrical (CO)4Re—Re(CO)4 unit. This unit is presumably formed through a concerted process involving carbonyl/sulfur exchange in the nonsymmetrical octacarbonyl (CO)3(S2CPR3)Re—Re(CO)5 generated after the coupling of the bromo derivative with the carbonyl anion. Complexes 3a—b can be obtained more directly by adding S2CPR3 to [Re2(CO)8(μ-H)(μ-CH=CHnBu)], which is formed by irradiation of Re2(CO)10 with 1-hexene. Hydride addition to the central carbon atom of the S2CPR3 ligand of 3a-b occurs with loss of PR3, to give the anion [Re2(CO)8(μ-S2CH)]- which may be isolated as a salt with the PPN+ cation. The octacarbonyl compounds 3a-b can be converted into hexacarbonyl complexes [Re2(CO)6(μ-S2CPR3)] (5a-b) by heating in toluene or octane at reflux temperature. According to an X-ray crystal-structure determination of the derivative 5a (R=Cy), the loss of one carbonyl ligand from each rhenium atom is accompanied by the rearrangement of the S2CPR3 ligand which changes its bonding mode from η1(S);η1(S′) donating four electrons to η3(S,C,S′);η2(S,S′) donating eight electrons.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301025
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  • 105
    Digitale Medien
    Digitale Medien
    Interactions in Molecular Crystals, 118. The Sodium(benzo-15-crown-5) Salt of 2, 6-Di(tert-butyl)-4-methylphenol, a Sodium Phenolate with an Extremely Short Na+…O- Distance: Structure and Density Functional Calculations (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1533-1537 
    Details
    ISSN: 0009-2940
    Schlagwort(e): 2,4,6-Trialkylphenol deprotonation ; Sodium/benzo-15-crown-5 solvation ; Crystal structure ; Density functional calculation ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The structure of crystals, isolated in low yield, from the attempted metallation of diphenylmethane in tetrahydrofuran solution containing benzo-15-crown-5 at a sodium metal mirror is determined, surprisingly, to be the sodium (benzo-15-crown) salt of 2,6-di(tert-butyl)-4-methylphenol, an antioxidative stabilizer to prevent ether peroxide formation. The structure of the solvent-shared contact ion pair (monoclinic P21/n, Z = 4, R1 = 0.06) proves a strong Na+…O- interaction at the extremely short distance of only 216 pm, a sixfold O-coordination of the Na+ cation in a pentagonal pyramid, and a hemispherical distortion of the crown ether. Density functional calculations at the B3LYP/6-31G* level, based on the structural data, reproduce, within a one-dimensional hypersurface approach, the rather short Na+…O- distance, and predict Mulliken charges of +0.32 for Na′ and -0.71 for 0-, as well as a considerable polarization of the trialkyl phenolate anion.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301029
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  • 106
    Digitale Medien
    Digitale Medien
    Palladacycles as Reactive IntermediatesDedicated to Prof. Dr. Dietrich Döpp on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1567-1578 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Metallacycles ; Palladium catalysis ; Domino reactions ; Polycyclic ring systems ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Palladacycles are discussed as the key intermediates of some important preparative ring forming reactions; their reactivity depends strongly on the ring size. The existence of 5-membered palladacycles, and even 4-membered palladacycles, is now firmly established, whereas the knowledge of 6-membered and larger palladacycles is based mainly on mechanistic considerations. The role of 5-membered palladacycles as catalysts is described briefly.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301104
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  • 107
    Digitale Medien
    Digitale Medien
    Olefin Carbonylation Catalysis with Cationic Palladium Complexes: Selectivity and Possible Intermediates (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1557-1565 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Carbonylations ; Alkenes ; Palladium ; Asymmetric catalysis ; P and N ligands ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Palladium complexes L2PdX2 containing various group Va ligands and weakly coordinating anions are active catalysts for the carbonylation of olefin substrates. These catalytic systems, though gaining significance in industry for the synthesis of polyketones, are normally characterised by a low chemoselectivity. This derives from the numerous possibilities for initiation and termination reactions which lead to different catalytic cycles and from facile multiple alternating insertion reactions of olefins and carbon monoxide. Based on experiments carried out under conditions of low selectivity and on previously published data, the factors involved in the control of the regio-, chemo- and stereoselectivity for those reactions are discussed, taking current ideas and model studies involving the above palladium complexes into consideration.
    Zusätzliches Material: 3 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301103
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  • 108
    Digitale Medien
    Digitale Medien
    Dichlorogermylene-Alkyldichlorophosphane Reactions Revisited: Characterisation of Bis(trichlorogermyl)phosphanes, Trichlorogermyldiphosphanes, and Ge-P Heterocycles (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1611-1618 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Alkyldichlorophosphanes ; Insertions ; Carbene homologues ; Germanium ; Phosphonium germanate(II) ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reactions of alkyldichlorophosphanes 1 (RPCl2; R = tert-butyl: 1a, R = isopropyl; 1b, R = 1-adamantyl: 1c) with the germanium dichloride dioxane complex were followed by 31P NMR. Depending on the organic substituents and the reaction conditions, mixtures of trichlorogermylphosphanes RP(GeCl3)2 4a-c, RPHGeCl3 5a-c, diphosphanes R(H)PP(H)GeCl3 6a-c, R(Cl)PP(H)GeCl3 7a, b cyclophosphanes, and Ge-P heterocycles such as triphosphadigermolanes (RP)3(GeCl2)2 8a, b and tetraphosphagermolane (RP)4)GeCl2 10b are formed. As a further unexpected byproduct of the reaction of 1a with GeCl2-dioxane, a small amount of tri-tert-butyl(trichlorogermyl)cyclotetraphosphane 9a was isolated. From the reaction of 1c with two equivalents of GeCl2-dioxane, separation from byproducts 5c and 6c by crystallisation furnished colourless crystals of 4c (R = 1-adamantyl) as the first pure organylbis(trichlorogermyl)phosphane. Surprisingly, the reaction of isoprophylphosphane with germanium tetrachloride, intended to prepare 5a, led to crystalline isopropylphosphonium trichlorogermanate(II) 11. The structures of molecular 4c and 9a and ionic 11 were determined by X-ray crystallography.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301109
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  • 109
    Digitale Medien
    Digitale Medien
    Synthesis and Structure of Trimethyllead Niobocene DihydrideDedicated to Professor Jörg Lorberth on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1629-1631 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Lead ; Niobium ; Hydrides ; Group 5 ; Group 14 ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reaction of niobocene trihydride [Cp2NbH3] with ClPbMe3 in the presence of amine affords the plumbido dihydride complex [Cp2NbH2(PbMe3)] (1). Compound 1 represents the first example of a stable complex with neighbouring hydride and terminal plumbyl substituents. The structure of this compound has been established by NMR and IR spectroscopy and confirmed by an X-ray structure analysis.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301112
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  • 110
    Digitale Medien
    Digitale Medien
    Chlorides and Acetylacetonates of Transition Metals as Catalysts for the Oxidation of 1-Indanol by Sodium Percarbonate (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1655-1658 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Catalysis ; Oxidations ; Transition metals ; Sodium percarbonate ; 1, 2-Dichloroethane ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The screening of metal chlorides and metal acetylacetonates as catalysts for the oxidation of 1-indanol by sodium percarbonate (at reflux in 1,2-dichloroethane in the presence of small amounts of Adogen 464) has been carried out. The efficiency of the process depended on the nature of the transition metal and its oxidation state but, except for iron, was not greatly influenced by the nature of the ligands. Good conversions and yields have been obtained using PdCl2, RhCl3, RuCl3 and, particularly, MoO2(acac)2 as catalysts.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301116
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  • 111
    Digitale Medien
    Digitale Medien
    Contribution to the Chemistry of Boron, 240 . Studies on Benzo-1,3,2-diphosphaborolanes, Benzo-1,4,2,3-diphosphadiborinanes and Benzo-1,5,2,3,4-diphosphatriborepanesDedicated to my friend Prof. Dr. A. Meller on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1677-1692 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Benzo-1,3,2-diphosphaborolanes ; Benzo-1,3,2-diphosphaborolane dimmers ; Benzo-1,4,2,3-diphosphadiborinanes ; Rearrangement reaction ; Pentacarbonyl chromium complexes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A series of benzo- 1,3,3-diphosphaborolanes C6H4(PR)2BR' (R = H, iPr, SiMe3; R' = R2N, R) has been prepared by several routes and characterized by spectroscopic and - in part - by X-ray diffraction methods. They feature pyramidal P atoms with the substituents in antiperiplanar positions. The P atoms act as coordination sites for the (CO)5Cr fragment. In contrast to the R2N-bearing benzo-1,3,2-diphosphaborolanes, the derivative C6H4(PH)2BCMe3 (4f) dimerizes by additional B-P bond formation to produce a pentacyclic system (4f)2. - The reaction of C6H4(PHNa)2 with B2(NMe2)2Cl2 in THF/hexane yields the acyclic phosphanylborane Me2NB(PH-C6H4PH2)2 (15). However, if C6H4[P(iPr)Li]2 is allowed to react with B2(NMe2)2Cl2, the benzo-1,4,2,3-diphosphadiborinane 13 is obtained, together with its rearrangement product 2-bis(dimethylamino)borylbenzo-1,3,2-diphosphaborolane 14 which dimerizes to (14)2.  -  In contrast, the almost planar ring of the 2,3-dimesitylbenzo-1,4,2,3-diphosphadiborinane (16) possesses P and B atoms with a planar geometry. Short B-B and B-P bonds suggest that this new heterocycle can be regarded as a 6π electron system. Moreover, the benzo-1,5,2,3,4-diphosphatriborepane 18 forms readily forms readily from C6H4(PHNa)2 and Br(Me2N)B-B(N-Me2)-B(NMe2) Br to give a tub-shaped seven-membered C2B3P2 ring system with the P atoms in a pyramidal and the B atoms in a planar environment.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301120
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  • 112
    Digitale Medien
    Digitale Medien
    Geminal di(hypersilyl) Compounds  -  the Synthesis and Structure of Bis[tris(trimethylsilyl)silyl]methanol (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1709-1714 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Silicon ; Strained molecules ; Silanes, sterically congested ; Tris(trimethylsilyl) silanes ; Silenes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Tris(trimethylsilyl)silyllithium (1) reacts with methyl formate in diethyl ether (molar ratio 2:1) to give 1,2-di(hypersilyl)- ethylene 13. The formation of 13 proceeds through the intermediates formyl tris(trimethylsilyl)silane (4) and lithium bis-[tris(trimethylsilyl)silyl]methoxide (5). In diethyl ether, the alkoxide 5 spontaneously eliminates lithium trimethylsilanolate thereby generating 1,1-bis(trimethylsilyl)-2-[tris(trimethylsilyl)silyl]silene (9), which undergoes a formal [2+2] cycloaddition with the carbonyl compound 4 to afford 13. This was verified by crossover experiments. In Pentane, the alkoxide 5 is moderately stable. Thus, the intermediate 5, prepared by reaction fo 1 with tert-butyl formate in pentane. was protonated with water to give the di(hypersilyl)methanol 6 in good yield. The structure of 6 in good yield. The structure of 6 was elucidated by an X-ray crystal structure analysis, which expectedly revealed tremendous distortions of the molecular skeleton. Thus, the spatial demand of the two extended hemispherical (Me3Si)3Si groups forces a widening of the Si-C-Si angle at the central sp3 carbon atom to a value of 135.5°.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301123
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  • 113
    Digitale Medien
    Digitale Medien
    Compounds of Germanium and Tin, 22 - Reactions of a Silyene with a Germylene and a Stannylene: Formation of a Digermene with an Unusual Arrangement of the Substituents and of a Stannane (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1733-1737 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Silicon ; Germanium ; Tin ; Carbene homologues ; Digermene ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reaction of the diaminosilylene :Si(tBuNCH2CH2NtBu) (5) with the diaminogermylene :Ge(tBuNCH2CH2NtBu) is thought to proceed via a germasilene → silylgermylene rearrangement and dimerisation to furnish the (Z)-1,2-diamino-1,2-disilyldigermene (Z)-9. The X-ray structure analysis of (Z)-9 reveals a long Ge—Ge bond length of 245 pm and a large trans-bent angle of 42°. Air-oxidation of (Z)-9 takes place with retention of configuration at the germanium atoms to provide the corresponding substituted (Z)-2,4-digerma-1,3-dioxetane (Z)-10. Treatment of 5 with the stannylene :Sn[N(SiMe3)2)2 gives, as a final product, the hydridodisilylstannane 12. The structures of (Z)-10 and 12 were also determined by X-ray crystallography.
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301205
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  • 114
    Digitale Medien
    Digitale Medien
    A Novel Approach to the Synthesis of Endohedral Fullerenes as Demonstrated by Endohedral Barium Fullerenes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1761-1764 
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    ISSN: 0009-2940
    Schlagwort(e): Endohedral ; Barium ; Fullerenes ; Dibarium fullerenes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A new route to endohedral fullerenes involving the evaporation of carbon and a metal at different positions, i.e. at different temperatures, in a radio-frequency furnace is described. For the first time, endohedral barium fullerenes within the composition range Ba@C74 to Ba@C136 have been produced in high yields as compared to hollow fullerenes, and have been extracted with CS2. Ba@C60, and Ba@C70, are only soluble in CS2 following sublimation. Furthermore, the first nonlanthanoid dimetallo fullerenes ranging in composition from Ba2@C88 to Ba2@C116 have been obtained. All endohedral barium fullerenes were characterized by mass spectrometry. Properties such as sublimation behaviour, solubility, and sensitivity to air have been studied.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301209
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  • 115
    Digitale Medien
    Digitale Medien
    N′,N′,N″,N″-Tetramethylguanidine-Substituted Phosphoryl Compounds as Ligands in Transition Metal Chemistry - Unusual Modes of CoordinationDedicated to Professor Roald Hoffmann on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1825-1832 
    Details
    ISSN: 0009-2940
    Schlagwort(e): N′, N′, N″, N′-Tetramethylguanidine ; Phosphoryl ligands ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Methyl- and tert-butylphosphonic bis(N′,N′,N″,N″-tetramethylguanidinide) 1 and 2 were allowed to react with various transition metal compounds. The resulting complexes were studied by IR spectroscopy, mass spectrometry and, in the case of 10, by NMR spectroscopy. In the case of the compounds 7-10 the metal was coordinated only via the imino nitrogen atoms of 2, (IR evidence). X-ray structure analyses were performed for [L1CoBr2]2 6, L2CuCl2 9, and L2PdCl2 10 (L1 = 1, L2 = 2). In 5 L1 acts as an N,O bridging ligand, leading to tetrahedral coordination at Co and eightmembered (-Co-O-P-N-)2 rings. In 6 coordination by L2 chelates the metal atom through two N atoms, leading to PN2M rings; the coordination geometry is distorted planar.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301219
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  • 116
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    Digitale Medien
    Synthesis of Functionalized Carbamates through a Palladium-Catalyzed Reductive Carbonylation of Substituted Nitrobenzenes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 13-22 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Carbamates ; Catalysis ; Substituted nitrobenzenes ; Palladium ; Reductive carbonylation ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The palladium-catalyzed reductive carbonylation of ortho and para-substituted nitrobenzenes has proven to be an attractive route for the synthesis of functionalized carbamates. For the Pd(1, 10-phenanthroline)2(triflate)2 catalyst system, the scope of the reaction has been studied. Substrates with electron-donating substituents at the para position were found to decrease the catalytic activity, most probably as a result of their relatively low oxidizing capacity. the selectivity towards the desired carbamate, however, was increased for these substrates. Under the influence of electron-withdrawing substituents the azoxybenzene and azobenzene derivatives became important side products. Introduction of large steric hindrance at the ortho position of the nitro substrates gave rise to an interesting side reaction, viz. methoxylation of the aromatic ring. The methoxylation reaction appeared to occur on an intermediate species in the catalytic cycle. Several functionalities have shown to be resistant to the reaction conditions required for the conversion ot the nitro group. Especially with 4-nitrobenzoic acid, an extremely high activity and selectivity was found, thus yielding a very convenient synthesis for N-protected amines containing carboxylic acid function.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300104
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  • 117
    Digitale Medien
    Digitale Medien
    Dimeric Silver(I) Complexes of Some Isothiazole-Based LigandsDedicated to Prof. Dr. Rolf Gleiter on the occasion of this 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 95-100 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Isothiazole complexes ; Dinuclear silver(I) complexes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A series of isothiazole-based potential ligands bearing substituents with additional donor sites in the 5-position of the heterocycle was synthesized [3-Me-5-R-C3HNS; R = CH=N(CH2)2py (1), CH=NCH2py (2), CH2N(CH2CH2NEt2)2 (4), (CH2)2SMe (5)]. Upon reaction with AgO3SCF3 they formed complexes [(1)AgOSO2CF3]2 (6), [(2)AgOSO2CF3]2 (7), [(4)Ag]2+2(O3SCF-3)2 (8) and [(5)AgOSO2CF3]2 (9), respectively. 6, 8 and 9 were shown by X-ray structural analyses to consist of dimeric units L2Ag2+2, either discrete (8), coordinated by terminal CF3SO-3 units (6). In 8 and 9 the isothiazole moiety is bonded to the metal center via the ring-N. The coordination potential of the isothiazole heterocycle is discussed.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300115
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  • 118
    Digitale Medien
    Digitale Medien
    Synthesis and Structure of Binuclear Single-Bridged Bis[(phosphane)gold(I)]halogenonium Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 115-118 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Gold complexes ; Bromonium complex ; Halogenonium complex ; Halogen, two-coordinate ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Reactions of (R3P)AuX (X = Cl, Br, I) with [(R3P)Au]+ BF-4 obtained from (R3P)AuCl and AgBF4 in tetrahydrofuran, lead to cationic binuclear gold(I) complexes of the general formula ([(R3P)Au]2X}+ BF-4. A number of chloro- (R = Ph, o-Tol, Mes, Bzl, Et), bromo- (R = Ph, o-Tol, Mes) and iodo-bridged (R = Ph, Mes) complexes of this type have been isolated and identified on the basis of their analytical and spectroscopic data. The crystal structure of bis[(triphenylphosphane)gold(I)]bromonium tetrafluoroborate was determined by single-crystal X-ray diffraction. The cations contain two-coordinate bromine atoms with an Au-Br-Au angle of 96.83(3)°.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300119
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  • 119
    Digitale Medien
    Digitale Medien
    A Specific Route to Enantiomerically Pure Asymmetric (η6-Arene)(η4-1,5-cyclooctadiene)Ru(0) ComplexesDedicated to Professor Rolf Gleiter on the occassion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 123-130 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Arene complexes ; Ruthenium compounds ; Electrophilic substitution ; Lithiation ; Catalysis ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Chiral or achiral (arene)(COD)Ru complexes can be made by replacing the η6-ligands of (η4-1,5-COD)(η6-1,3,5-cyclooctatriene)Ru (1) or (η4-1,5-COD)(η6-naphthalene)Ru (2) by a suitable arene. This well known reaction has been extended to mono- and dibromoarenes and we report a novel route to substituted (arene)(COD)Ru species, utilizing (bromoarene)-(COD)Ru as starting materials. These facilitate a rapid bromine-lithium exchange reaction with nBuLi at low temperatures and the lithiated species react readily with alkyl chloroformates as electrophiles. By using chiral electrophiles [alkyl = (-)-menthyl] enantiomerically pure or diastereomeric complexes containing CO2R* groups are formed, depending on the symmetry of the original complex. A diastereomeric 1:1 mixture was separated by recrystallization. All (arene)-(COD)Ru complexes tested so far are useful as catalysts for the hydrogenation of simple alkenes at room temperature.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300121
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  • 120
    Digitale Medien
    Digitale Medien
    Recent Advances in C-F Bond Activation (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 145-154 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Fluorocarbons ; C-F bond activation ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The main reaction pathways which lead to the breaking of C-F bonds in perfluoroalkanes and -arenes are discussed. Emphasis is placed on recent developments and on the mechanistic patterns that emerge.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300203
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  • 121
    Digitale Medien
    Digitale Medien
    Metal Atoms in the Synthesis of Metal Clusters, VIII.On the Reaction of Sterically Demanding Cyclopentadiene Ligands with Cobalt Atoms: Synthesis, Crystal Structure, Spectroscopic Behavior, and Reactivity of Di-, Tri- and Tetranuclear Hydrido Clusters of CobaltDedicated to Professor IV Siehert on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 161-170 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The metal-vapor reactions of Co atoms with 1,3-tBu2CpH (1a), 1,3-tBu2CpH (1a), 1,2,4-tBu3CpH (1b) and EtMe4CpH (1c) are described. With 1a the two mononuclear complexes [(η5-tBu2Cp) (η4-tBu2-1,3-cyclopentadiene)Co] (2a) and [(η5-tBu2Cp)2Co] (3a) were isolated, together with the dinuclear cobalt cluster [{(η5-tBu2Cp)Co}2H3] (4a) and trace amounts of the tetranuclear cluster [{(η5-tBu2Cp)CoH}4] (5a). The molecular structures of 3a and 4a were determined by X-ray diffraction. Reaction of 1b with Co atoms afforded a single product, the dinuclear cluster [{(η5-tBu3Cp)Co}2H3] (4b), whose molecular structure was determined by single-crystal X-ray diffraction. Both, 4a and 4b exhibit extremely short Co-Co distances [2.244(1) (4a) and 2.242(1) Å (4b)], as found for the Me5Cp analog [{(η5-Me5Cp)Co}2H3] (4c). Reaction of an isomeric mixture of Me4EtCpH (1c) with Co atoms furnished the mononuclear sandwich [ (η5-Me4EtCp)(η4-Me4Et-1,3- cyclopentadiene)Co] (2b), the trinuclear hydridocobalt cluster [{(η5-Me4EtCp)Co}3H4] (6a) and the tetranuclear hydridocobalt cluster [{(η5-Me4EtCp)Co}4H4] (5c). The molecular structure of 5c was determined by X-ray crystallography and revealed a tetrahedral arrangement of the cobalt atoms. The electrochemical behavior of the dinuclear complexes 4a-4c was studied by cyclic voltammetry. Reversible redox couples were found for all three compounds, with a correlation between the degree of alkyl substitution and their respective cathodic shifts. Compounds 4a and 4b react with CO to yield the mononuclear and dinuclear complexes [ (η5- CpR)Co(CO)2] (R=1,3-tBu2, 1,2,4-tBu3) (7a and 7b) as well as [{(η5-CpR)CO}2(CO)2] (8a and 8b). Reaction of the trinuclear hydridocobalt cluster 6a and its Me5Cp analog 6b with AgBF4 in the presence of PEt3 yielded the heteronuclear clusters [{η5-Me4CPR)Co}3AgP(Et)3H4]+[BF4]- (R=Et, Me) (9a and 9b). 9a was structurally characterized by X-ray crystallography.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300205
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  • 122
    Digitale Medien
    Digitale Medien
    Linked Benzylamido-Cyclopentadienyl Ligands: Synthesis and Characterization of Alkyl Titanium Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 209-215 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Titanium ; Amidocyclopentadienyl ligand ; Alkyltitanium compounds ; Lewis acids ; Agostic interactions ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Titanium complexes of the general type Ti(η5:η1-C5H4Si-Me2NCH2C6H3X2-2,5)Cl2 (X=H, F), containing a linked benzylamido-cyclopentadienyl ligand, were prepared by reaction of Ti(η5-C5H4SiMe2Cl)Cl3 with lithium amide Li(NHCH2C6H3X2-2,5). A single-crystal X-ray structural analysis of Ti(η5: η1-C5H4SiME2NCH2C6H3F2-2,5)Cl2 revealed a conformation in the solid state in which the aryl ring is turned away from the metal center. Ti(η5:η1-C5H4SiMe2NCH2C6H5)Cl2 can be alkylated with a variety of reagents to form extremely sensitive complexes of the type Ti(η5-C5H4SiMe,2NCH2C6H5)R2 (R=Me, CH2 C6H5, CH2SiME3, CH2CMe2C6H5). Reaction of Li2[C5Me4SiMe2NCH2C6H5] with TiCl3(THF)3 gave Ti(η5: η1-C5Me4SiMe2NCH2C6H5)Cl2, which can also be alkylated to form dialkyl complexes of the type Ti(η5:η1-C5Me4SiMe2NCH2C6H5)R2(R=Me, CH2C6H5, CH2SiMe3, C6H5).A single-crystal X-ray structural analysis of Ti(η5:η1-C5Me4SiMe2NCH2C6H5)(CH2C6H5)2 suggests the presence of α-agostic bonding of one of the titanium-bound CH2C6H5 groups to the titanium center.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300211
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  • 123
    Digitale Medien
    Digitale Medien
    Concave Reagents,22. Cyclopropanation of Alkenes with Ethyl Diazoacetate: Copper(I) Complexes of Concave 1,10-Phenanthrolines as Diastereoselective Catalysts (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 231-234 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Diasteroselective cyclopropanation ; Copper compounds ; Homogeneous catalysis ; Molecular recognition ; Bimacrocycles ; Alkenes ; Macrocyclic ligands ; Heterocycles ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Concave 1,10-phenanthrolines 1a-c have been used as ligands in the copper(I)-catalyzed cyclopropanation of alkenes 2 with ethyl diazoacetate. The complexes proved to be efficient cyclopropanation catalysts and exhibited an enhanced diastereoselectivity, particularly in the reactions of cyclic alkenes 2b-d. The preferred formation of exo-cyclopropanes 3b-d can be explained by the concave shape of these catalysts.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300215
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  • 124
    Digitale Medien
    Digitale Medien
    Synthesis of Polycyclic Hydrocarbons by Palladium-Catalyzed Cross-Coupling Reactions of Vinylic Bromides with Diphenylacetylene (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 261-265 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Polycycles ; Hydrocarbons ; Palladium catalysis ; Domino processes ; Cross coupling ; Homogeneous catalysis ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Vinylic bromides of type 1 undergo cross-coupling reactions with diphenylacetylene (5) leading to various polycyclic hydrocarbons. The ratio of the 1:1 to the 1:2 products can readily be controlled by varying the reaction conditions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300220
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  • 125
    Digitale Medien
    Digitale Medien
    Silver Chloroacetate: Crystal Structure and Thermal Polymerization Mechanism (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 291-294 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Halogenoacetates ; Silver salts ; Solid-state reactions ; Polymerization ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The structure of silver chloroacetate was determined by single-crystal X-ray structure analysis. This represents the first salt of a monohalogenoacetic acid with a monovalent metal whose structure was determined with high precision. The salt undergoes a thermally induced solid-state polymerization to polyglycolide under elimination of silver chloride. A probable mechanism for a structure-determined reaction in the solid state is discussed.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300224
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  • 126
    Digitale Medien
    Digitale Medien
    Preparation of Methyl 2-[Bis(trimethylsiloxy)phosphoryl]-3,3,3-trifluoro-2- (trimethylsiloxy)propionate and Some Derivatives-Molecular Structure of Methyl 2-[Bis(trimethylsiloxy)phosphoryl]-3,3,3-trifluoro-2-hydroxypropionate (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 279-281 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Methyl trifluoropyruvate ; Tris(trimethylsilyl) phosphite ; Methyl 2-[bis(trimethylsiloxy)phosphoryl]-3,3,3- trifluoro-2-(trimethylsiloxy)propionate ; Bis(trimethylsilyl) [(2,2-difluoro-l-trimethylsiloxy)ethenyl]- phosphonate ; Solid-state structures ; Fluorine ; Phosphorus ; Silicon ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Methyl trifluoropyruvate (1) and tris(trimethylsilyl) phosphite (3) reacted to give methyl 2-[bis(trimethylsiloxy)phosphoryl]- 3,3,3-trifluoro-2-(trimethylsiloxy) propionate (4). Partial hydrolysis furnished propionate 6, the molecular structure of which was obtained in the solid state. Attempted trimethylsilylation of the methylcarboxylato group in 4 using iodotrimethylsilane caused the formation of bis(trimethylsily1) [(2,2- difluoro- 1 -trimethylsiloxy)ethenyl]phosphonate (8). For comparison, methyl pyruvate (2) and 3 gave methyl 2-[bis(trimethylsiloxy)phosphoryl]-2-(trimethylsiloxy)propionate (5).
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300222
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  • 127
    Digitale Medien
    Digitale Medien
    Generation and Synthetic Application of Metallated Methyl Isopropenyl Ether, A Substitute for Acetone Enolate (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 45-48 
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    ISSN: 0009-2940
    Schlagwort(e): Metallated methyl isopropenyl ether ; Tetrahydrofurans ; 1-Oxabicyclo[4.3.0]heptanes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Methyl isopropenyl ether (1) has been metallated at low temperature with a 1:1 molar mixture of n-BuLi/t-BuOK in THF-hexane, and subsequently functionalized with a variety of electrophilic reagents. At temperatures higher than - 30°C, the metallated methyl isopropenyl ether (2) decomposes with formation of allene. When the suspension of 2 is allowed to warm up to room temperature in the presence of an additional equivalent of n-BuLi, the intermediary allene is converted into 1-propynyllithium (2c), which reacts with propylthiocyanate to give 1-propylthio-1-propyne (4). Some of the functionalization products were subjected to acidic hydrolysis affording the expected methyl ketones.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300107
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  • 128
    Digitale Medien
    Digitale Medien
    (EIZ)-Equilibria, 19 Part 18: Ref.[19].  -  [*I X-ray structural analyses. Dimeric α-Lithio-2,6-dimethylstyreneDedicated to Prof. Joseph Klein on the occasion of his 80th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 585-592 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Aggregations ; Complex, tert-butyl methyl ether ; diastereotopomerization, (EIZ) ; NMR, coupling, constants, HH, CH, CLi ; NMR, Lithiation shifts ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Improved preparations of 2,6-dimethylstyrene (5) and its α-bromo derivative (10) are described. The Br/Li exchange reaction of 10 provides single crystals of the title compounds 11 or 12, which were characterized as disolvated dimers by X-ray analyses. A similar dimer persists in diethyl ether, tert-butyl methyl ether, and toluene at all accessible temperatures, with significant lithiation NMR shifts (relative to 5) partially due to charge delocalization from the sp2-carbanionic center. Some NMR coupling constants are typical of the dimeric aggregate. The configurational (E,Z) lability is quantified in toluene solution.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300509
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  • 129
    Digitale Medien
    Digitale Medien
    Dinuclear Cobalt(II) Complexes of Pyrazole Ligands with Chelating Side ArmsDedicated to Prof. Dr. Walter Siebert on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 605-613 
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    ISSN: 0009-2940
    Schlagwort(e): Pyrazolate complexes ; Dinuclear complexes ; Bridging ligands ; Cobalt ; Conformational analysis ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A series of pyrazole-based potential ligands bearing polydentate amine substituents in the 3- and 5-positions of the heterocycle has been synthesized [3,5-bis(R2NCH2)-pyzH R2N = Me2N(CH2)3NMe (2aH), [Me2N(CH2)3]2N (2bH), (Et2NCH2CH2)2N (2cH)]. Upon reaction with two equivalents of CoCl2 they form complexes LCo2Cl3 (3a-c; L = 2a-c, respectively) which are shown crystallographically to contain a dinuclear metal core bridged by both the pyrazolate unit and a chlorine atom, with each cobalt center carrying a further terminal chlorine atom. Two of the ligand side arms in 3b, c are dangling, thus leading to five-coordination of the cobalt(II) centers in all cases. Addition of two equivalents of NaBPh4 to solutions of 3b, c induced coordination of the formerly dangling side arms to the metal centers by substitution of the terminal chlorine atoms. The resulting compounds [LCo2Cl](BPh4)2 (4b, c, respectively) were characterized by X-ray structure analyses. They can be viewed as dinuclear linked versions of tran-type complexes [(tran = tris(aminoalkyl)amine] with distorted trigonal-bipyramidal coordination spheres around cobalt(II). Conformational analyses employing force-field calculations were carried out for 4b, c in order to rationalize the conformations observed in the solid state with regard to the accessible conformational space.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300511
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  • 130
    Digitale Medien
    Digitale Medien
    Gold Coordination by 2-(Diphenylphosphanyl)aniline (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 647-650 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Gold(I) coordination ; 2-(Diphenylphosphanyl)aniline ; Ambidentate P ; N ligands ; P Ligands ; Ligand effects ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reaction of 2-(diphenylphosphanyl)aniline (1) with (tetrahydrothiophene)gold(I) chloride in the molar ratio 1:1 gives a stable molecular complex 2, in which the gold atom is bonded to the phosphorus atom. Reaction of two equivalents of ligand 1 with one equivalent of the salt [(tht)2Au]ClO4 results in the displacement of both thioether ligands, affording the ionic complex {[(2-NH2C6H4)PPh2]2Au}+ ClO-4 (3a), in which the metal center is exclusively P-coordinated. Treatment of [(tht)2Au]ClO4 with ligand 1 (1:1) affords the mixed P/S-coordinated complex 4, the structure of which has been confirmed by single-crystal X-ray diffraction. The reaction of ligand 1 with [(Ph3P)Au]+ BF-4 leads to a mixture of products which are components of an equilibrium between the unsymmetrical salt {[(2-NH2C6H4)PPh2]Au(PPh3)} BF-4 with the two symmetrical species 3b (the BF-4 analogue of 3a) and [(Ph3P)2Au]+ BF-4, With {[(Ph3P)Au]3O}+ BF-4 as the aurating agent, the ligand 1 (molar ratio 1:1) is converted into a polynuclear complex 7, which is tentatively assigned a structure with intimate aggregation of six gold atoms.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300516
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  • 131
    Digitale Medien
    Digitale Medien
    Masthead (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997) 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300601
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  • 132
    Digitale Medien
    Digitale Medien
    Monomeric Phosphanylgalanes  -  Synthesis and Structural Characterization (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 663-668 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Phosphanylgallanes ; Gallium amino compounds ; P Ligands ; Gallium ; Ab initio calculations ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The monomeric phosphanylgallanes R2GaPR'R (R = tmp, Mes; R' = H, tBu; R' Mes, tBu), the diphosphanylgallane mesGa(PtBu2)2, and diphosphandiylbisgallane [tmp2GaP-(tBu)]2, have been synthesized from alkali metal phosphides and substituted gallium chlorides. Low-temperature NMR studies of the phosphanylgallanes reveal no barrier to rotation about the gallium-phosphorus bond. Analysis of the crystal structures of tmp2GaPtBu2 confirms the monomeric nature of these molecules. The gallium-phosphorus bond lengths are found to be 237.5, 233.5, 235.4 pm (averaged), and 242.3 pm, respectively, with all phosphorus atoms being pyramidally coordinated.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300519
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  • 133
    Digitale Medien
    Digitale Medien
    Fully Chlorinated N-Silyl Amides of Titanium and Tungsten  -  Crystal Structure of Cl3SiNW(Cl3)N(SiCl3)2 (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 701-704 
    Details
    ISSN: 0009-2940
    Schlagwort(e): N-Silyl amides ; Precursor ; 14N-NMR ; Titanium ; Tungsten ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reaction of hexachlorodisilazanyllithium (Cl3Si)2NLi (1), with TiCl4 leads selectively to the novel fully chlorinated amides (Cl3Si)2NTiCl3 (2) or [(Cl3Si)2N]2 TiCl2 (3), respectively, depending on the molar ratio of the starting materials. The analogous reaction of 1 with WCl6 yielded the amide imide Cl3SiN=W(Cl3)N(SiCl3)2 (5) by elimination of SiCl4. The relative amounts of the starting materials had no effect on the formation of 5. 14/15N- and 29Si-NMR data on the starting materials and products show significantly different effects, when compared with those of analogous N-trimethylsilyl derivatives, due to the lower energy of the electrons in the N—Si and N—M ß bonds. The crystal structure of 5 (triclinic, space group P1) was determined by X-ray structure analysis.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300605
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  • 134
    Digitale Medien
    Digitale Medien
    Reactions of Pt3Ru6(CO)2(μ3-H)(μ-H)3 with Phos[phanes  -  The Synthesis and Structural Characterizations of [Pt(PMe3)3H][Pt3Ru6(CO)21(μ3-H)(μ-H)2] and [Pt3Ru6(CO)20(PPh3)(μ-H)3(μ3H)] (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 729-733 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Platinum ; Ruthenium ; Cluster anions ; Phosphanes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reactions of [Pt3Ru6(CO)21(μ-H)3(μ3-H)] (1) with PMe3 and PPh3 have produced the salts [Pt(PR3)3H]-[Pt3Ru6(CO)21(μ3-H)(μ-H)2], 5a and 5d, R = Me and Ph in the yields 9% and 22%, respectively. By contrast the reaction of 1 with PPh3 in the presence of Me3NO has yielded the phosphane-substituted derivative [Pt3Ru6(CO)20(PPh3)μ-H)3(μ3-H)] }(6) in 22% yield. Compounds 5a and 6 were characterized by single crystal X-ray diffraction analysis. Compounds 5a and 5d are salts of the anion [Pt3Ru6(CO)21(μ3-H)(μ-H)2]-. The anion contains a layer segregated Ru3Pt3Ru3 structure similar to that of 1 with two bridging hydride ligands on one Ru3 triangle and one semi-triply bridging hydride ligand on the other. The cation [Pt(PR3)3H]+ was evidently formed by the abstraction of platinum from other molecules of 1. Compound 6 is a PPh3 derivative of the parent 1 that also contains the layer segregated stacking of Ru3 and Pt3 triangles. The PPh3 ligand is coordinated to one of the ruthenium atoms in an axial position.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300609
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  • 135
    Digitale Medien
    Digitale Medien
    Synthesis, Characterization and Polymerization Behavior of {(1R, S)-2-(η5-9-Fluorenyl)-1-[η5-(1R,S)-indenyl]-1-phenylethane}zirconium dichloride and {(1R,S)-Cyclohexyl-2-(η5-octahydro-9-fluorenyl)-1[η5-tetrahydro-(1R,S)-indenyl]ethane}zirconium Dichloride (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 747-751 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Epoxides ; Fluorenyl ligands ; ansa-Zirconocenes, non-symmetrical ; Polymers ; Polymerizations ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Epoxystyrene (1a) were converted into their corresponding alcohols, 2a-c, by treatment with either fluorenyl- or indenyllithium. These alcohols were then further converted into their trifluoromethanesulfonate derivatives, 3a-c. Subsequent reaction of the triflates with fluorenyl-, indolyl-, or tetraphenylcyclopentadienyllithium resulted in formation of 2-(9-fluorenyl)-1(1-indenyl)-1-phenylethane (4a), and 1-(9-fluorenyl)-2-(5-tetraphenylcyclopentadienyl)ethane (4c). The ansa-metallocene (1-(R,S)-2(η5-9-fluorenyl)-1-[η5-1(R,S)-indenyl]-1-phenylethane]ZrCl2 (5a) was prepared from the dilithio salt of 4a. Hydrogenation of 5a with H2/PtO2 leads to {1(R,s)-cyclohexyl-2-(η5-octahydro-9-fluorenyl)-1-[η5-tetrahydro-1(R,S)-indenyl]ethane]ZrCl2 (6a. The complexes 5a and 6a were activated with methylalumoxane (MAO) and used for propene polymerization. The solid state structures of 4b, 4c, and 5a are reported.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300612
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  • 136
    Digitale Medien
    Digitale Medien
    Lithium 2,2,6,6-Tetramethylpiperidinoselenolate: An Unsymmetrical Dimer with an Unusually Coordinated Lithium (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 119-122 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Selenolate ; Aminoselenolate ; Lithium compound i Ab initio calculations ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Lithium 2,2,6,6-tetramethylpiperidide inserts elemental selenium into its Li-N bond with the formation of lithium 2,2,6,6-tetramethylpiperidinoselenolate 1. In the crystal 1 is an unsymmetric dimer. One lithium atom is coordinated tetrahedrally by two molecules of tetrahydrofuran and two selenium atoms, the other lithium atom exhibits an approximately rectangular-planar coordination by two N,Se-chelating groups. The lithium atoms are bridged by two selenium atoms thus forming a planar Li2Se2 core. Ab initio Hartree-Fock calculations show 1 and the hypothetical symmetric dimer 2 to be of equal energy, whereas the non-chelated dimer 3 is of distinctly higher energy. Exclusive crystallization of 1 is most likely a consequence of its large dipole moment of 6.18 D. Calculations also show that the deformation of the observed geometry around the uniquely coordinated lithium atom in 1 towards distorted tetrahedral or complete planarity leads to an increase of energy. Excessive charge transfer from selenium to nitrogen explains the overwhelming tendency for the N,Se-chelating bonding.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300120
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  • 137
    Digitale Medien
    Digitale Medien
    Ligand- Substrate Communication in Group 4 Aminopyridinato Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 789-794 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Agostic interactions ; Ligand effects ; Titanium ; Zirconium ; Aminopyridinato ligands ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Tris(aminopyridinato) zirconium and ansa-aminopyridinato titanium complexes have been sythesized. The reaction of (TMS-APy)3-Zr-Cl (4-methyl-2-trimethylsilyl-aminopyridine=TMS-APy-H) with trimethylsilylbutadiynyl lithium generated in situ affords (TMS-APy)3—Zr—C≡C—C≡C—TMS (1). (TMS-apy)3-Zr-Me2 (2). Compound 2 shows an agostic interaction of the dimethylamido moiety. The reaction of Ti(NMe,2),4 with silox(Apy-H)21,3-di(4′-picolin-2′-yl-amino)-1,1,3,3-tetraisopropyldisiloxane=silox (APy-H)2] gives rise to silox(Apy)2-Ti-(NMe2)2-Ti-[NMe,2)2 (3). Complex 3 reacts with ε-caprolactam to form a caprolactamato complex (4). X-ray crystal structure analyses of 1, 2, 3 and 4 are reported. The complexes 1, 2, 3 and 4 may be considered to be strained donor-functionalized amido(metal) complexes due to the η2 binding mode of the ligand cores, TMS-APy and silox(APy)2, to meet the requirements of the ancillary coordinated substrates is observed. Thus, aminopyridinato complexes seem to be valuable model compounds for investigations of ligand-substrate communications in early transition metal chemistry.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300618
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  • 138
    Digitale Medien
    Digitale Medien
    Masthead (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997) 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300701
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  • 139
    Digitale Medien
    Digitale Medien
    1,3-Di-tert-butyl-2,2,4,4-tetrahalocyclodisilazanes - Synthesis, X-ray Crystal and Gas-Phase Structures (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 835-837 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Cyclodisilazanes ; 1,3-Di-tert-butyl-2,2,4,4-tetrafluorocyclodisilazane ; 1,3-Di-tert-butyl-2,2,4,4-tetrachlorocyclodisilazane ; Structure elucidation ; Electron diffraction ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The syntheses of 1,3-di-tert-butyl-2,2,4,4-tetrachlorocyclodisilazane (3) and of di-tert-butyl-2,2,4,4-tetrafluorocyclodisilazane (4) are reported. The X-ray crystal structure of 3 and the electron-diffraction gas-phase structure of 4 have been determined. Both cyclodisilazanes possess planar four-membered rings and nearly planar configurations at the nitrogen atoms. The Si-N bond lengths are 171.1(1) pm and 170.6(3) pm and the Si⃛Si transannular distances 245.0(1) and 241.3(13) pm in 3 and 4, respectively.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300704
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  • 140
    Digitale Medien
    Digitale Medien
    Synthesis and Molecular Structure of a Rhenium Complex Derived from 8a-Amino-6-methyl-ergolineDedicated to Professor Roland Mayer on the occasion of his 70th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 839-841 
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    ISSN: 0009-2940
    Schlagwort(e): Rhenium ; Technetium ; 8a-Amino-6-methyl-ergoline ; Chelates ; Structure elucidation ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Current research in radiopharmaceutical chemistry is aimed at the design of technetium-based receptor-binding radiotracers because of the excellent nuclide properties of the isotope 99mTc. Tc tracers and the corresponding complexes of rhenium, as the inactive surrogate of Tc, are required to imitate organic agonists or antagonists of the receptor. We have started studies with ergolines, which are known to be dopamine substitutes. The present report deals with the functionalization of 8α-amino-6-methyl-ergoline (2) with a 2-mercaptoacetyl group, and the subsequent synthesis of the first rhenium complex containing a pendent ergoline moiety [Re- O(SSS)(RS)] (HSSSH = HS-CH2CH2-S-CH2CH2-SH and RSH = 8a-amino-N-(2-mercaptoacetyl)-6-methyl-ergoline) (4). The molecular structure of the rhenium complex was determined by X-ray crystal structure analysis.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300705
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  • 141
    Digitale Medien
    Digitale Medien
    Aminotroponimines as Ligands for Yttrium and Lanthanide Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 859-862 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Yttrium ; Lanthanum ; Samarium ; Lanthanides ; Aminotroponiminate ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reaction of N-isopropyl-2-(isopropylamino)troponimine, [(i-Pr)2ATI]H, with KH in THF affords [(i-Pr)2ATI]K. This is a useful starting material for the preparation of the mono-, bis- and tris-substituted compounds [[i-Pr)2ATI]YCl2-(THF)2}2, [(i-Pr)2ATI2Y[O(2,6,t-Bu2C6H3)] and [(i-Pr)2-ATI]3Ln (Ln = Y, La, Sm), which can be obtained from ([i-Pr)2ATI]K and LnX3 and LnX3 (X = Cl, I), or Y[O(2,6-t-BuC6H3)]3. All compounds have been characterized by spectroscopic methods. The monosubstituted yttrium complex {[(i-Pr)2ATI]YCl2(THF)2}2 has also been investigated by single crystal X-ray diffraction.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300708
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  • 142
    Digitale Medien
    Digitale Medien
    Mono- and Bicyclic Organometallic Ring Systems with Exocyclic C=C and C=S BondsDedicated to Professor Joachim Strähle on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 871-877 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Cobalt ; Cyclopentadienyl complexes ; Heterocycles ; Electrophilic addition ; Insertion reaction ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The cobaltaheterocycles [C5H5Co{κ2(C,S)-C(=CH2)-N(R)C(=S)S](PMe2Ph)] (5-7), which contain both an exocyclic C=C and C=S bond, were prepared from the iminoacylcobalt compounds [C5H5Co(C(CH3)=NCH} (PMe2Ph)]I (2-4) on treatment with either CS2/NaOCH3 or K[S2CNMe2], respectively. While protonation of 5 (R = CH3) and 7 (R = CH2Ph) with HBF4 occurs at the exocyclic C=CH2 bond to give cations containing a CoC(CH3)N(R)C(=S)S ring, the methylation of 5 and 7 with [OMe3]BF4 takes place at the exocyclic C=S bond and generates five-membered heterocycles heterocycles with an SCH4 substituent. The reaction of 5-7 with S8 leads to the elimination of the phosphane ligand and affords the bicyclic dithiolenecobalt complexes 14 - 16 in moderate to good yields. On treatment of 5-7 with C2(CO2R′)2 (R′ = Me,Et), an insertion of the alkyne into the C=CH2 bond occurs and five-membered ring systems 19-22 with an unsaturated exocyclic =C(CO2R′)-C(CO2R′)=CH2 group are formed. As in the case of 5 and 7, protonation and methylation reactions of 19 also take place at different sites leading to cations with either a delocalized CoCN or NCS unit.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300710
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  • 143
    Digitale Medien
    Digitale Medien
    Nickel(II) Complexes of Chiral Tripodal N,O,S-Ligands: Square-Planar vs. pseudo-Octahedral Coordination in the Solid State and in Solution, Metal-Induced Racemization of the Ligand (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 891-897 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Ligands, tridentate ; Nickel ; Thioethers ; Bioinorganic chemistry ; Racemization ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The complexation behavior of three chiral, tripodal N,O,S-ligands with nickel(II) salts was examined. It was found that the coordination mode of the ligands (bidentate N,O and N,S; tridentate N,O,S) and of the central nickel ion (square-planar vs. pseudo-octahedral) is not simply an intrinsic property of the ligand-metal combination, but also a function of the counter ions and of the solvent of crystallization. In the case of one ligand, a diamagnetic square-planar and a paramagnetic pseudo-octahedral form could be switched back and forth, by just changing the solvent of crystallization from methanol to ethanol. By using an enantiomerically pure tripodal N,O,S-ligand, a metal induced racemization was unveiled which would have otherwise remained undetected.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300713
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  • 144
    Digitale Medien
    Digitale Medien
    Chemistry in Environmentally Benign Media, 8Part 7: Ref. Hydroxymethyl Functionalized Phosphanes as Building Blocks to new Water-Soluble Gold(I) Complexes - synthesis, Characterization, and X-ray crystal Structures of Novel Tetrahedral [Au{P(CH2OH)3}4]+ and Trigonal Planar [Au(Ph2PCH2OH)3]+ Gold (I) Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 907-911 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Hydroxymethyl phosphanes ; Gold ; Trigonal gold(I) complexes ; Tetrahedral gold(I) complexes ; P ligands ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reactions of water-soluble phosphanes P(CH2OH)3 (1) and Ph2PCH2OH (2) with NaAuCl4 in aqueous or alcoholic media, produced the water/alcoholic-soluble AuI complexes [Au(Ph(CH2OH)3)4]+ (3) and [Au(Ph2PCH2OH)3+ (4) in near quantitative yields. The X-ray structures of 3 and 4, reported in this paper, confirm the structures of these new generation of water-soluble transition metal complexes. All compounds were characterized by 1H-, 13C-, 31P-NMR spectroscopy and mass spectrometry. The structures of 3 and 4 were determined by X-ray crystallography.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300716
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  • 145
    Digitale Medien
    Digitale Medien
    Synthesis and Structure of 2,2′ -Boryl-, Germyl-Silyl-, and Stannyl-Substituted 1,1′ -Binaphthyl SystemsDedicated to Professor Hans Paulsen on the occasion of his 75th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 923-932 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Biaryls ; Boron ; Chirality ; Cooperative Effects ; Lewis acids ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A number of Lewis acid binaphthyl systems, substituted in 2-or 2,2′-position, are synthesized by lithiation of 2,2′-dibromo-1,l ′-binaphthyl (5), followed by addition of various electrophiles. Stepwise lithiation and subsequent borylation with trimethyl borate leads to the bromoboronic acid 6, which can be stabilized by esterification with pinacol giving 7. By increasing the reaction mixture to 2 equiv. of n-butyllithium and 2 equiv. of methyl borate the path to the binaphthylmonoboronic acid ester 9 is opened up. A further increase in the quantity of electrophile also leads to the binaphthylbisboronic acid ester 12. The 2,2′-disubstituted silyl, germyl, and stannyl derivatives 13a-15a are accessible in good yields. Treatment with boron halides leads exclusively to methyl/halogen exchange, giving the bidentate Lewis acids 13b-15b, the former of which can be bridged by oxygen.Only in case of the bis(tributylstannyl)binaphthyl 16a does ipso substitution occur in the presence of boron trichloride, giving the bis(dichloroboryl)-substituted binaphthyl 16b which can then be hydrolysed to 11. The structures of the majority of the compounds were investigated by X-ray diffraction. In case of the 2,2′-disubstituted compounds 13a-15a the naphthyl groups are orientated perpendicular to each other. The intra- and intermolecular interactions are dominated by this binaphthyl system. In case of the oxygenbridged compounds 13c and 14c the angle between the naphthyl planes decreases to about 70°. This also has an effect on the packing of the molecule; in this instance the orientation of two naphthyl in neighbouring molecules is nearly parallel. The structure of the diboronic acid is dominated by intra- and intermolecular hydrogen bonding.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300718
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  • 146
    Digitale Medien
    Digitale Medien
    Temperature-dependent Ring-Opening and -Closure of a Cyclic Phosphane-BoraneDedicated to Professor Gottfried Huttner on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 951-954 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Phosphane-boranes ; Medium-sized rings ; Ring opening and closure ; Temperature-dependent NMR studies ; Phosphorus ; Boron ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A phosphane-borane (3) with the P-B bond integrated into a seven-membered ring was prepared from 4-pentenyl-diphenylphosphane (4) by hydroboration using 9-borabicyclononane (9-BBN). The product was confirmed to have a ring structure in the solid state by single crystal X-ray diffraction. The P-B distance of 2.057(2) Å is indicative of a standard donor-acceptor bond similar to the type found in homologous five- and six-membered rings. The room-temperature 31P-NMR signal of the compound in various solvents (δ ≈ - 15) is not compatible with the cyclic structure and suggests that ring opening occurs as the compound is dissolved. Variable-temperature NMR work corroborated this assumption, and the enthalpy of ring closure was determined to be ΔH = -30.5(4) kJmol-l. In CD2C12 at -90°C, δ31P is shifted to +3.5 ppm to low field, suggesting virtually complete ring closure under these conditions.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300722
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  • 147
    Digitale Medien
    Digitale Medien
    The Coordination Chemistry of Fluorocarbons: Group-I and Group- II Metal Ion Complexes of Fluoro Macrocycles (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 963-968 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Fluorine ; Macrocycles ; Complexes ; Sodium ; Barium ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Two new fluoro macrocycles BenzoFN2O3 and F(N2O2)2C2H4 were synthesized in the reactions of 1,3-bis(bromomethyl)-2-fluorobenzene with benzo-diaza-15-crown-5 and 1,2-bis(diaza-12-crown-4)ethane, respectively, in 30% yield each. Close CF...metal ion interactions in the respective alkaline metal complexes in solution are evidenced by characteristic shifts of the 19F-NMR resonances of up to δ = 18.7 relative to the free ligand and by a decrease of the 1J(CF) coupling constant of up to 20 Hz, which is most pronounced in BenzoFN2O3 · Li+ and F(N2O2)2C2H4 · K+. In BenzoFN2O3· Li+ a1J(19F-7Li) of 15.5 Hz was observed, which is indicative very close CF...Li+ interactions in solution. In the X-ray crystal structures of BenzoFN2O3 · Na+ [CF⃛Na+ 246.8(2) pm], 26-fluoro-4,7,13,16-tetraoxa-1, 10-diazatricyclo[ 8.8.7.1 20,24 ] - hexacosa-20,22,24(26)triene · Na+ (CF⃛Na+ 267.1(2) pm) and 21 -fluoro-3,6,9,12,15,18-hexaoxabicyclo[ 18.3.1 1,20]heneicosa- l(24),20,22-triene. Ba2+ [CF⃛Ba2+ 299.0(3) pm] short CF⃛metal interactions were found. Such close CF⃛metal ion interactions do not result in a lengthening of the C-F bonds, which is not a sign of weak CF⃛metal ion interactions, since a Cambridge Structural Database search revealed that a shortening of the C-O bond length is also not observed in crown ether complexes of alkaline metals.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300725
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  • 148
    Digitale Medien
    Digitale Medien
    (η6-Arene)ruthenium(II) Labeling of Amino Acids and Peptides with Aromatic Side-ChainsDedicated to Professor W. Beck on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 981-988 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Ruthenium ; Tyrosine ; Tryptophan ; Sandwich complexes ; Bioorganometallic chemistry ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Bis(arene)ruthenium(II) complexes of the type [(η6-cymene)Ru(η6-aa)](CF3SO3)n (2-9) containing L-tyrosine and L-tryptophan derivatives may be prepared by treatment of [(η6-cymene)Ru({CH3)2CO}3](CF3SO3)2 with the appropriate bioligand in CH2Cl2, for fully protected compounds and CF3COOH for α-amino acids (aa) with unprotected amine or carboxylic acid groups. Whereas the tyrosine and tryptophan methyl ester complexes [(η6-cymene)Ru(η6-H2tyrOMe)](CF3SO3)3 (4) and [(η6-cymene)Ru(η6-H2trpOMe)](CF3-SO3)3 (8) contain trications with protonated amino functions, the remaining compounds all exhibit dications. The crystal structure analysis of [(η6-cymene)Ru(η6-HtyrOH)](CF3SO3)2 (5) confirms a marked distortion towards an η5-oxohexadienyl coordination with deprotonation of the aromatic side chain. Although facial isomers are formed in an effectively 1:1 ratio for all tryptophan derivatives fractional crystallization allowed an X-ray structural characterization of the β-isomer of [(η6-cymene)Ru(η6-ActrpOMe)](CF3SO3)2 (6). Chemospecific labeling of the tryptophan side chain was established for the mixed dipeptide phenylalanyltryptophan.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300728
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  • 149
    Digitale Medien
    Digitale Medien
    Enantioselective Catalysis, XVPart XIV: Ref. Preparative and Structural Chemistry of Diastereomeric Derivatives of 3-Phosphanylpyrrolidine and Their Palladium(II) Complexes - Asymmetric Grignard Cross-Coupling Reaction (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 989-1006 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Cross-Coupling ; Grignard reactions ; Nickel ; Pyrollidinephosphane ; Cooperative effects ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The preparation of both diastereomeric derivatives of 3-(diphenylphosphanyl) pyrrolidine with chiral (tetrahydrofuran-2-yl)methyl and [(N-neopentyl)pyrrolidin-2-yl]methyl groups as substituents on the pyrrolidine nitrogen atom and of (2S,4S)-1-benzyl-4-(diphenylphosphanyl)-2-(methoxymethyl) pyrrolidine is reported. [3S,P(RS)]-3-(phenylphosphanyl) pyrrolidine, bearing an additional chiral center on phosphorus, is the starting material for the preparation of phosphanes, in which one phenyl group of the PPh2 moiety is substituted by an 2-methoxyphenyl (=An) or 2,4,6-trimethoxyphenyl (=TMP) group. PdI2 complexes of these ligands were separated into diastereomers by chromatography on silica gel columns. The structural chemistry of these novel phosphane diastereomers and their PdI2 complexes is investigated by X-ray crystallography and NMR. At the P,N-coordinated palladium center displacement of an iodide anion is found for P,N,N′ ligands only. In the nickel complex catalysed cross-coupling reaction, yielding 3-phenyl-1-butene, we obtain the highest enantioselectivities in the case of simple 1-alkyl-3-(diphenylphosphanyl)pyrrolidine ligands. The enantioselectivity obtained with diastereomeric derivatives, bearing additional ether or amine ligating sites is mainly determined by the chiral center in 3-position of the 3-(phosphanyl) pyrrolidine part of these ligands. Optimisation of enantioselectivity with these ligands can be carried out by a variation of the ligand to nickel ratio and by the choice of the vinyl halide used as starting compound. The catalytic cycle must contain at least one catalytically active species, bearing more than one β aminoalkylphosphane ligand.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300729
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  • 150
    Digitale Medien
    Digitale Medien
    The Reactivity of Complexes of Nickel(0) and Platinum(0) Containing Benzyne and Related Small-Ring Alkynes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1029-1042 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Nickel ; Platinum ; Aryne complexes ; Cyclohexyne complexes ; Insertions ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The preparation and reactivities of cyclohexyne and aryne complexes of platinum(0) and nickel(0) are reviewed. These complexes undergo insertions with unsaturated molecules such as alkenes, alkynes, isocyanides, CO and CO2. In the case of the nickel- benzyne complexes, consecutive insertions are observed with alkynes, leading to substituted naphthalenes with good regioselectivities. A possible mechanism for these double insertions, based on a combination of steric and electronic factors, is discussed in detail.
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300803
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  • 151
    Digitale Medien
    Digitale Medien
    Synthesis and Structures of Sodium Phenylhydrazides (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1053-1062 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Lithium ; Hydrazides ; Solvates ; Clusters ; Sodium ; Structure elucidation ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Monomeric Li(Ph)N—N(Ph)SiMe3 · 2 OEt2 was obtained by deprotonating the respective hydrazine with nBuLi in the presence of diethyl ether. Reaction of NaN(SiMe3)2 with PhHN-N(SiMe3)2 in a benzene/tetrahydrofuran mixture provided monomeric Na(Ph)N—N(SiMe · 3 THF, or Nd(Ph)N—N(SiMe3)2 · THF using a small amount of THE Its TI IF ran be replaced by diethyl ether or tert-butyl methyl ether to give 1:l solvates. These associate, forming chains in the solid state via ηn coordination (n = 2, 3) of their phenyl groups to the sodium centers of adjacent molecules. In contrast, not only deprotonation but also desilylation occurs on reaction of NaN(SiMe3)2 with H(Ph)N—N(Ph)SiMe3 or of NaNH2 with (Me3Si)HN—NPh2) The latter reaction results in the formation ot hexameric (NaHN—NPh2)6 which adopts a face-sharing double-cubane structure.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300806
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  • 152
    Digitale Medien
    Digitale Medien
    Characteristic Features of Neutral Cyclopropenylium-Like Compounds: Synthesis, Structure, and Chemical Behavior of a Cyclopropenylioborate Betaine (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1079-1084 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Cyclopropenylium compounds ; Methylenecyclopropenes ; Isonitrile insertion ; Methylenecyclobutenone imine derivatives ; Cyclopropenylioborate betaines ; C-C coupling ; Zirconium ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Bis(propynyl)zirconocene was treated with B(C6F.5)3 and then with two equivalents of tert-butyl isocyanide to yield the organometallic three-membered ring product 8. Subsequent hydrolysis gives the substituted (2-iminioethylidene)cyclopropeneborate betaine system 9 that exhibits a pronounced cyclopropenylioborate betaine character. This follows from its characteristic structural features (X-ray crystal-structure analysis of the isomer cis-9) and its chemical features. Complex 9 undergoes a very facile cis/trans isomerization by formal rotation around the exocyclic partial CC-double bond (ΔG+ ≈ 17 kcal mol-1). Compound 9 reacts cleanly in methanol solution with tert-butyl isocyanide by insertion and ring enlargement to form the four-membered ring system 12. Compound 12 was also characterized by X-ray diffraction.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300809
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  • 153
    Digitale Medien
    Digitale Medien
    Chiral Metal Carbene Modified [2.2]Metacyclophanes: Synthesis, Structure, and Chiroptic Properties (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1105-1111 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Carbene complexes ; Chromium ; Cyclophanes ; Chirality ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Pentacarbonyl(4-[2.2]metacyclophanyl(methoxy)carbene)-chromium(0) (6) was prepared according to the Fischer route from 4-bromo[2.2]metacyclophane. Aminolysis with non-chiral and chiral amines affords aminocarbene complexes 7-12. X-Ray structure analyses for 6 and its aminocarbene analogs 7 and 8 indicate that the incorporation of the chromium-carbene fragment has no significant influence on the deformation of the [2.2]metacyclophane skeleton.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300812
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  • 154
    Digitale Medien
    Digitale Medien
    The Role of the 2,4,6-Tris(trifluoromethyl)phenylamino Group in Stabilizing New Phosphorus-, Arsenic-, and Germanium-Containing Main-Group Compounds and Transition-Metal Derivatives (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1113-1121 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Phosphorus ; Arsenic ; Germanium ; Inorganic heterocycles ; Metal amides ; Fluorinated ligands ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reactions of potassium Rf-amide [Rf = tris(trifluoromethyl)phenyl](2) with PCl3, AsC13, and GeC12 · dioxane yield new four-membered inorganic heterocycles [RfNPCl]2 (3), [RfNAsC1]2 (4), and [RfNGe]2 (5), respectively. On the other hand, the reaction of Rf-amide 2 with two equivalents of RfPCl2 leads to the formation of the imino-γ3-phosphane RfN=PRf (6) and the diamino-γ3-phosphane (RfNH)2PRf (7). The iminophosphane 6 reacts with Ni(CO)2(PPh3)2 and forms the complex [Ni(PPh3)2(RfN=PRf)] (9), in which the imino- phosphane coordinates to the metal through the phosphorus lone pair. Treatment of lithium amide 2 with transition metal chlorides ZnCl2 and FeCl2 yields the imido/amido spirocyclic metal derivatives 9 and 10, respectively. Compounds 3-10 have been extensively characterized by their analytical and mass, IR, and NMR (1H, 19F, and 31P) spectroscopy. Further, the molecular structures of all the compounds have been unambiguously determined by single-crystal X-ray diffraction studies. The diazadigermetidine 5 crystallizes in a fluorescent-yellow orthorhombic and a yellow monoclinic crystal modification. The results obtained reveal the role of Rf, group in stabilizing new multiple bonded systems and inorganic heterocycles. A skeletal rearrangment of the Rf ligand is observed in the reactions leading to compounds 9 and 10. Moreover, the preparation of compounds 9 and 10 indicates the limitation of the use of this ligand in the preparation of new metal-amide systems, especially where the metal atoms have a strong tendency for the formation of strong M—F bonds.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300813
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  • 155
    Digitale Medien
    Digitale Medien
    Polynuclear Gold(I) Complexes of Functionalized Thiols and Dithiols (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 641-646 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Gold ; S ligands ; Carboxylato complexes ; Thioether complexes ; Sulfonium complexes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Treatment of 2-mercaptoaniline with {[(Ph3P)Au]3O}+ BF-4 leads to a regioselective auration to give the (2-aminophenyl)sulfonium complex {(2-H2NC6H4S[Au(PPh3)]2}+ BF-4 (1) as the sole product. With the same reagent, 4-hydroxyphenyl)sulfonium salt 2, and 2-mercaptopyridine is converted into the 2-pyridylsulfonium salt 3. Dinuclear auration of the thiol functions is thus clearly favoured over the reaction at any of the other functional groups (-NH2, -py, -OH). As shown in earlier work, this is also true for HS-functional carboxylic acids. With an excess of the oxonium reagent, however, 2-mercaptosuccinic acid was now found to be converted into a tetranuclear complex with a doubly aurated sulfonium group and monoaurated carboxylate functions (4). Bis(2-mercaptoethyl) ether and thioether react with the oxonium salt to give tetranuclear bis(sulfonium salts) 5, 6, with bifurcated {-S[Au(PPh3)]2}+ groups at both ends. Structural studies of compounds 1, 5 and 6 showed the cations to be aggregated into centrosymmetrical dimers through short Au-Au contacts. Compound 5 forms one-dimensional infinite chains through a similar aggregation via the two bifurcated sulfonium end groups of each individual dicationic unit. The dications of compound 6 are associated only into centrosymmetrical dimers leaving one of the two sulfonium groups of each unit without auriophilic contacts to neighbouring dications, probably owing to an internal Au-S contact with the thioether function.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300515
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  • 156
    Digitale Medien
    Digitale Medien
    On the Protonation of Fluoro Cryptands and the Possibility of CF…HN+ Hydrogen Bonds (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 633-640 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Fluorine ; Macrocycles ; Cryptands ; Protonations ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The protonation of several fluoro cryptands synthesized from 1,3-bis(bromomethyl)-2-fluorobenzene and diaza-macrocycles (diaza-12-crown-4, diaza-15-crown-5, diaza-18-crown-6 and 2,3-benzodiaza-15-crown-5) has been investigated by 1H-, 13C- and 19F-NMR spectroscopy, X-ray crystal structure analysis and IR spectroscopy, with a view to detecting possible CF…HN hydrogen bonding. From the crystal structures of mono- and diprotonated 23-fluoro-4,7,20-trioxa-1,10-diazatricyclo[8,7,5,112,16]tricosa-12,14,16(23)-triene (FN2O3·H+ and FN2O3·2H+) it is apparent that protonation leads to a shortening of the non-bonded nitrogen-fluorine and nitrogen-oxygen distances and consequently to O·HN hydrogen bonds. A related type of interaction involving fluorine appears possible since short N(H)…F distances (281.2-286.6 pm) with NHF angles between 130-140° are observed. A Cambridge Structural Database search was performed and 27 structures with short CF…HN contacts were found. On the other hand, IR spectra do not give any clear evidence in favor of CF…HN hydrogen bonding since the N-H vibrations in FN2O3…H+ and FN2O3…2H+ as well as in FN2O4…2H+ do not experience longwave shifts relative to the N-H vibrations of the reference systems HN2O3·H+, HN2O3…2H+ and HN2O4…2H+.HN2O3 and HN2O4 are almost identical to FN2O3 and HN2O4, respectively, the only difference being that the single fluorine atom of the fluoro cryptands is replaced by hydrogen. NMR spectroscopic evidence concerning CF…HN interactions is ambiguous: (i) A spin-coupling between 1H and 19F (NH…F) is observed. (ii) The 1JCF value is reduced by up to 15 Hz upon protonation of the fluoro cryptand. (iii) An NMR competition experiment between FN2O3 and HN2O3 yields no evidence for an increased basicity of the fluoro cryptand. Finally, it can be stated that evidence in favor of CF…HN hydrogen bonds is inconclusive; should such an interaction exist it will certainly be very weak.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300514
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  • 157
    Digitale Medien
    Digitale Medien
    Diastereoselective Synthesis of Tricarbonyl(thiophene)chromium Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 659-662 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Thiophene derivatives ; Complexation, diastereoselective ; Chromium ; Heterocycles ; Steric hindrance ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: 2,3-Disubstituted 2-hydroxyalkylthiophenes 9 and 10 were synthesized in a five-step sequence and their diastereoselective complexation with the Cr(CO)3 fragment leading to the corresponding tricarbonyl(thiophene)chromium complexes 11 and 12 was investigated. The diastereoselectivity achieved in the complexation reaction was up to 85% d. e. and depends primarily on the bulkiness of the substituent in the 3-position of the thiophene. The relative configuration of the stereogenic center and the planar element of chirality of complex 11a was determined by X-ray diffraction analysis.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300518
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  • 158
    Digitale Medien
    Digitale Medien
    Solid-State 13C-NMR-Spectroscopy, 3.Part 2: G. Maier, H.-O. Kalinowski, C. Weber, M. Henrich, Magn. Reson. Chem. 1995,33, 290-296. - Solid-State 13C-NMR-Spectroscopic Investigations of α-(Dimethylamino)-benzyllithium Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 683-686 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Hybridization ; Lithium coordination ; Structure elucidation ; NMR-spectroscopy ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: α-(Dimethylamino)benzyllithium (1a) and its complexes, 1b-f, have been characterized by their solid-state 13C-NMR spectra. The spectra are comparable to those recorded in solution and can be used to reveal the structures of the different solvates of the title compound.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300603
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  • 159
    Digitale Medien
    Digitale Medien
    Reaction of 1,3-Dialkyl-4,5-dimethylimidazol-2-ylidenes with 2-Bromo-2,3-dihydro-1H-1,3,2-diazaboroles (Alkyl=iPr and tBu)Dedicated to professor Adolf Zschunke on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 705-710 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Boron ; Diazaboroles ; Carbenes ; Heterocycles ; Imidazoles ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: 2-Bromo-2,3-dihydro-1H-1,3,2-diazaboroles (3a-c) were synthesized by cyclocondensation of dilithiated 1,4-diazabutadienes (5a-c) with boron tribromide in hexane. 3a was also obtained by sodium amalgam reduction was conducted in ether solvents, diboroxane (2) resulted as the main product. Compound 3a and 1,3-dialkyl-4,5-dimethylimidazol2-ylidenes (6a, b) underwent halide displacement to afford the borolylimidazolium salts 7a, b. Compounds 2, 3a-c, and 7a, b were characterized by elemental analyses and spectroscopic methods (1H, 11B, 13C NMR; Ir; MS). The molecular structures of 2 and 7a were established by single-crystal X-ray diffraction analyses.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300606
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  • 160
    Digitale Medien
    Digitale Medien
    Well-Defined Metallodendrimers by Site-Specific Complexation (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 725-728 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Dendrimers ; Metal complexes ; Nanostructures ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Strong multiple complexation of transition metal ions, Cu(II), Zn(II) and Ni(II) with different generations of well-defined poly(propylene imine) dendrimers as multi(tridentate) ligands has been used to construct nanoscopic assemblies of defined structure and size incorporating a distinct number of metal ions from 2 up to 32.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300608
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  • 161
    Digitale Medien
    Digitale Medien
    [CR(CO)5PCl3]  -  A Starting Material for Phosphorus-Rich Px Ligand ComplexesDedicated to Prof. Dr. Joachim Strähle on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1299-1304 
    Details
    ISSN: 0009-2940
    Schlagwort(e): P ligands ; P-P bond formation reaction ; Molybdenum ; Chromium ; Nickel ; Carbonyl complexes ; Main group elements ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: [Cr(CO)5PCl3] reacts with different metallates K[CpxMo(CO)3] [Cpx = ·5-C5H4tBu (Cp]), ·5-C5H3tBu2-1,3 (Cp))], K[CpFe(CO)2], K[Cp]Cr(CO)3], K[C}*Ni(CO)] and Na2[Cr2(CO)10] at -78°C in THF to yiel various P2, cyclo- P3 and cyclo-P5 ligand complexes of the formulae [Cp] Mo(CO)2 (.2-P3)] (1a), [Cp]Mo(CO)2(.3-P3)] (1b), [{CP'Mo-(CO)2}2(μ,.2-P2)] (2a), [{Cp]Mo(CO)2}2(μ, ·2-P2)] (2b), [Cp]Fe).5-P5)] (3), [(Cp'Cr)2(μ,.5-P5)] (4), [{Cp]Cr(CO)2}2-(μ,.2-P2)] (5), [(Cp*Ni)2(μ,.2-P2){Cr(CO)5}2] (6). [{(CO)5Cr}Cl2PPCl2{Cr(CO)5}] (7) and [{Cr(CO)5}2PCl (8). Comprehensive studies of the reaction pathway leading to formation of the cyclo-P3 product 1a give strong indications that a sequence involving metal-halogen exchange and stepwise P-P bond formation takes place, proceeding via [{CO}5Cr}Cl2PPCl2{Cr(CO)5}] (7) and the cyclo-P3 precursor compond [{Cp]Mo(CO)3}{Cp'Mo(CO)2}2{Cr(CO)5}(μ,.3:1:1-P3)] (9). The latter two complexes have been isolated and structurally characterized.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300919
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  • 162
    Digitale Medien
    Digitale Medien
    Synthesis and Crystal Structure of tert-Butylamino)di-tert-butyl)siliceniotrichloroaluminate, (Me3C)2Si=NCMe3·AlCl3, and Dimethylazomethine-Aluminium Trichloride, Me2C=NH·AlCl3Dedicated to Prof. A. Meller on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 753-755 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Silicenium ion ; Iminosilane ; Aluminate ; Silicon ; Aluminium ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Lithiated text-butylaminolfluorosilanes react with aluminum trichloride in ether, eliminating LiF to give AlCl3 adducts of iminosilanes  -  aminosiliceniotrichloroaluminates {R2Si-NCMe3·AlCl3}, which thermally form the dimethylazomethine- aluminium trichloride, Me2C=NH·AlCl3.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300613
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  • 163
    Digitale Medien
    Digitale Medien
    Sulfur Compounds, 199Part 198: R. Steudel, Y Drozdova, K. Miaskiewicz, R. H. Hertwig, W. Koch, J Am. Chem. Soc. 1997, 119, 1990.. Novel Titanocene Thiolato Complexes and Their Application in Preparing New Sulfur-Containing Heterocycles (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 757-764 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Titanocene complexes ; S ligands ; Organic polysulfanes ; Ligand transfer reactions ; Sulfur heterocycles ; Chalcogens ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Treatment of Cp2Ti(CO)2 (3) with the di- and polysulfanes 1,2,4-(CH2)2S3, C4S6 (9), C,7H10S3 (11), 1,2,4,6-(CH2)3S4 (16), C6H10S6(19), and S6 affords the titanocene chelate complexes Cp2TiS3(CH2)2 (8), (Cp2Ti)2C4S6 (10), Cp2TiS3C7H10 (13), Cp2TiS2C7H10 (14), Cp2TiS4(CH2)3 (17), Cp,2TiS6C6H6H10 (20), and Cp2TiS8 (23). 14 is also obtained from Cp2TiCl2 (1) and the geminal dithiol of norbornene. The analogous reaction with the dithiol of dicyclopentadiene yields Cp2TiS2C10H12 (15). In ligand transfer reactions, 8 reacts with SCl2 to give 1,2,3,5-tetrathiane (25), 10 provides 9 on reaction with Cl2, 13 when treated with S2Cl2 affords C7H10S5 (12), 15 reacts with S2Cl2Cl2 to give C10H12S4. 17 and SCl2 yield 1,2,3,5,7-pentathiepane (18), 20 is converted to C6H10S7 (22) on reaction with SCl2, and 23 yields S10 and 1,2,-C6H4(SCl)2, respectively. With phosgene, thiophosgene, and thionyl chloride, compound 15 yields the corresponding dithiocarbonate 26, the trithiocarbonate 27 and the trisulfane 2-oxide 28. The structure of 27 was determined by X-ray crystallography.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300614
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  • 164
    Digitale Medien
    Digitale Medien
    Synthesis of a Bisdienophilic Phthalocyanine and of Precursors for Repetitive Diels-Alder Reactions Based on Hemiporphyrazines and Phthalocyanines (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 801-806 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Unsymmetrical phthalocyanines ; Hemiporphyrazines ; Macrocyclic bisdienes and bisdienophiles ; Diels-Alder reactions ; Ladder polymers ; Cycloaddition ; Macrocycles ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The specific synthesis of a metal-free bisdienophilic phthalocyanine 193, suitable for repetitive Diels-Alder reactions, is reported. This was achieved by condensation of 191,3,3-trichloro-6/7-nitroioindolenine (191) and 4,9-dibutoxy-2,3,5,8-tetrahydro-1,3-diimino-1H-5,8-epoxybenz[f]isoindoline (2). The ability of 3 to undergo Diels-Alder reactions was tested by reaction with an excess of 1,2,3,4-tetraphenylcyclopentadienone (5). Experimental data of the hemiporphyrazines 9, 10, and 11, which can be used as precursors for the synthesis of ladder polymers, are also given in the Experimental Section.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300620
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  • 165
    Digitale Medien
    Digitale Medien
    Organometallic Molybdenum(V) Complexes with Promary Phosphane Ligands  -  Syntheses, Spectroscopic Properties, and Crystal Structures of [Cp′MoCl4(PH2R)] (R=2,4,6-Pri3C6H2, Cyclohexyl, Cp′=C5H4Me)Dedicated to Professor Dr. Joachim Strähle on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 807-812 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Methylcyclopentadeienyl molybdenum(V) tetrachloride ; Primary Phosphane ligands ; EPR spetroscopy ; Molybdenum ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: [Cp′MoCl4(CH3CN) (Cp′=C5H4Me) react with 2,4,6-triisopropylphenylphosphane or cyclohexylphosphane to give the phosphane complexes [Cp′MoCl4(PH2R)] [R=2,4,6-Pri3C6H2 (1)]. 1 and 2, were characterized spectroscopically (IR, MS) and by crystal structure determinations. EPR investigations in liquid and frozen solution confirmed the presence of Mo(V) species and the data were used to analyze the spin-density distribution in the first coordination sphere.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300621
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  • 166
    Digitale Medien
    Digitale Medien
    Preparation and Structures of Hexaphenyl- and Hexatolyltantalates(V) (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 903-906 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Hexaphenyltantalate ; Hexatolytantalate ; Trigonal prismatic coordination ; Transition metals ; Structure elucidation ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: By reacting TaCl5 with LiC6H5 and LiC6H4-4-CH3 salts, the anions Ta(C6H5)6 and Ta(C6H4-4-CH3)6 were obtained in small yields. They were structurally characterized by low-temperature single-crystal structure determination and found to have quite similar structures, which can be described as slightly distorted trigonal prismatic.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300715
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  • 167
    Digitale Medien
    Digitale Medien
    Synthesis and Structure of Allenyl-Substituted η6-Benzene(tricarbonyl)-chromium Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1135-1139 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Arene complexes ; Chromium ; Allenes ; Rearrangements ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The Cr(CO)3-complexed η6-phenylpropargylic alcohols 3 react in a displacement rearrangement with thionyl chloride or chlorodiphenylphosphane to give the chloro- or phosphoryl allenyl substituted η6-phenyl complexes 4 and 6, respectively. In the X-ray crystal structure of the novel organometallic allenic derivatives 4b and 6b the vicinal chloro or phosphoryl substituent and the benzene(tricarbonyl)chromium fragment are arranged coplanarily. Palladium/copper-catalyzed couplings of the chloroallene 4b with terminal alkynes disclose a facile access to ynallene derivatives 8, novel carbon-rich organometallic π-systems.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300816
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  • 168
    Digitale Medien
    Digitale Medien
    Raman and Infrared Spectra and Quantum Chemical Calculations for Trichlorophosphoranylidenesulfamoyl Chloride, CISO2N=PCI3 (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1141-1145 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Trichlorophosphoranylidenesulfamoyl chloride ; Vibrational spectroscopy ; Conformational properties ; Quantum chemical calculations ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Raman (3500-50 cm-l) and infrared (4000-400 cm-l) spectra of the title compound, ClSO2N=PCl3, were recorded for the solid and liquid phase. Additionally, the Raman spectrum of the compound dissolved in CCl4 was obtained and qualitative depolarization values were determined. The spectra of the liquid and solid phase were interpreted in terms of the existence of only one conformation possessing C1 symmetry, as predicted by quantum chemical calculations. A complete vibrational assignment is proposed based on the relative intensities, on group frequencies along with support from the normal coordinate analysis. The experimental fundamental vibrational modes are compared to those obtained from theoretical approaches employing the ab initio MP2/6-31G* method and a density functional approximation (B3PW91/6-31G*).
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300817
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  • 169
    Digitale Medien
    Digitale Medien
    Ab Initio Studies on Disubstituted closo-Icosahedral Heteroboranes, X2B10H10 [X = CH, SiH, N, P, and Sb] (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1147-1150 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Icosahedral heteroboranes ; Ab initio calculation ; Bonding models ; Aromaticity ; Nucleus Independent Chemical Shift [NICS] ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Ab initio theoretical studies on X2B10H10 (X = CH, SiH, N, P and Sb) have been done for all the three possible isomers. Unlike lower-vertex heteroboranes, all the hetero derivatives have shown similar trends in the relative stabilities, the 1,12-isomer being more stable followed by 1,7- and 1,2-isomers, except for N and Sb. No conventional 1,2-isomer for N could be found. Instead, a new nido isomer which is 18.1 kcal/mol higher in energy than the most stable isomer has been located. Any hetero group substitution to icosahedral R12H122- is found to be thermodynamically destabilizing. However, the Nucleus Independent Chemical Shift criterion shows that all compounds, except for 8, have similar aromaticity.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300818
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  • 170
    Digitale Medien
    Digitale Medien
    The Molecular Structures of Triaminosilanes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1159-1166 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Aminosilantes ; Structure elucidation ; Molecular conformations ; Configuration determination ; Nitrogen Planarity/Silanes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The structural chemistry of a series of triaminosilanes XSi(NR2)3 has been investigated in order to determine the ground-state configuration and conformation of these molecules. Theoretical studies and analogy with the isoelectronic XP(NR2)3 (X = CH2, O, Se, NSiMe3 etc.) and P(NR2)3 molecules suggest structures of Cs or C3 symmetry, with small energy differences between them. The molecular structure of HSi(NMe2)3 (1) has been determined by a single-crystal X-ray diffraction study at low temperature. Surprisingly, the molecules have a non-standard conformation with an irregular orientation of the three NMe2 groups. The hydrido-, chloro-, methyl-, and vinyltris(morpholino)silanes XSi[N(CH2CH2)2O]3 (X = H, Cl, Me, Vi; 2-5) were prepared from the corresponding chlorosilanes and morpholine (2, 3) or lithium morpholide (4,5). Their variable-temperature NMR spectra were studied and the molecular structures determined by single crystal X-ray diffraction. Compound 2 has a molecular geometry approaching mirror symmetry with one morpholino group significantly different from the other two. This structure resembles that of isoelectronic tris(amino)phosphines. Compounds 3-5 have structures with a propeller-like arrangement of the three morpholino rings approaching C3 symmetry for this part of the molecules. The chloro compound 3 shows the shortest Si-N bond lengths (average 1.690 Å), followed by 2 (1.708Å),5 (1.709Å) and 4 (l.712Å). The configuration of all nitrogen atoms is almost planar, with sums of the angles close to 360°, and the morpholino rings adopt a chair conformation. According to the solution NMR spectra the ring inversion is slow at low temperature, but the rings rotate freely about the Si-N bonds on the NMR time scale. The molecular structures are discussed in terms of steric and electronic effects of the substituents. Other model compounds, including (Me2N)3SiC6H4-4-Br (6), MeSi[N(CH2CH2)2NMe]3 (7) and PhSi[N(CH2)4]3 (8), could not be crystallized, but were characterized by their analytical and spectroscopic data.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300820
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  • 171
    Digitale Medien
    Digitale Medien
    Gold Coordination by Tertiary Phosphane Sulfides (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 955-958 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Phosphane sulfides ; Gold(I) complexes ; Sulfide coordination ; Phosphorus ; Sulfur ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Treatment of the ditertiary phosphane sulfides (CH2)n[PPh2S]2, 1a-1d, n = 1-4, with equivalent amounts of (dimethylsulfide)gold(I) chloride (Me2S)AuC1 affords the dinuclear complexes 2a-2d with an AuCl unit attached to each sulfur atom. The chlorides can be converted into the bromides 3a-3c by metathesis using KBr, or by reacting 1d with (tetrahydrothiophene)gold bromide. With [(Ph3P)Au]+ O3SCF3 as the aurating agent for the diphosphane disulfides, the corresponding dicationic products are obtained: {(CH2)n[SPPh2AuPPh3]2}2+ · 2 O3SCF3 (4b-4d, n = 2-4). An excess of the reagents does not lead to polygold clustering at the sulfur atoms, and P-S cleavage occurs instead to give sulfonium salts {S[Au(PPh3)]3}+ X-. The reaction of Ph3PS with equimolar quantities of [ (Ph3P)Au]O3SCF3 leads to the cationic 1:1 complex 5, and with an excess of the agent the P-S bond is ruptured. The structures of compounds 4b and 4d were determined by single-crystal X-ray diffraction. The dications have crystallographic centers ot inversion, the coordination at the gold atoms is linear [4b: 179.03(3)° 4d: 175.29(2)°] and the angles at the sulfur atoms are acute [4b: 97.76(4)° 4d: 96.37(3)°], but there are no short Au-Au contacts.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300723
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  • 172
    Digitale Medien
    Digitale Medien
    Synthesis and Iron-Binding Properties of Protochelin, the Tris (catecholamide) Siderophore of Azotobacter vinelandii (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 969-973 
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    ISSN: 0009-2940
    Schlagwort(e): Catecholamide ; Protochelin ; Ligand-promoted dissolution ; Iron ; Siderophores ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Protochelin, the tris(catecholamide) siderophore recently identified in the culture medium of A. vinelandii, can be synthesised by coupling of suitably protected azotochelin and aminochelin derivatives in preparative yields, Based on the ligand protonation constants of pK1 = 6.67, pK2 = 8.09 and pK3 = 9.68, the proton-independent stability constant for ferric protochelin could be estimated to be 1044.6. The solubilisation of FeIII hydroxide by protochelin has been investigated spectrophotometrically in aqueous solution at pH = 7. Since the production of protochelin by A. vinelandii depends on high molybdate levels in the growth medium, the studies have been carried out in the presence as well as in the absence of an equimolar amount of molybdate. Although the protochelin promoted dissolution of FeIII hydroxide is delayed significantly in presence of molybdate, the effect is far less pronounced than the one observed for azotochelin, the bis(catecholamide) siderophore of A. vinelandii.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300726
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  • 173
    Digitale Medien
    Digitale Medien
    Masthead (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997) 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300801
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  • 174
    Digitale Medien
    Digitale Medien
    Donor Complexes of Silylene, Germylene, and StannyleneDedicated to Professor Jürgen Hinze on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1013-1020 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Donor-acceptor complexes ; Silylene ; Germylene ; Stannylene ; Ab initio calculations ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The complexes of various donor molecules, AH3 (A = N, P, As, Sb, Bi) and AH2 (A = 0, S, Se, Te) with silylene, germylene, and stannylene (1Al ground state) were studied by means of quantum chemical investigations at ab initio level utilizing all valence electron basis sets and relativistic corrected effective core potential methods. Accordingly, the donor molecules are weakly bound, the association energies are in the range of 15-30 kcal per mole. The exothermic energies for adduct formation, i.e., the resulting binding energies for the donor complexes, decrease in the order silylene 〉 germylene 〉 stannylene. The population analysis indicates for NH3 and BiH3 only a weak bonding towards the XH2 fragment (X =Si, Ge, Sn) while the higher homologues (A = P, As, Sb) form ylide structures, 1.2-dipolaric in nature. The addition of two donor molecules has been studied for silylene and is much less favourable than donor mono-addition. For the donor mono-addition a dual parameter relationship between (a) the HOMO energies of the donor (n-orbital of the AH3 unit, n, p-orbitals for AH2) and (b) the covalent bond energies (from the literature) versus the binding energies of the donor-acceptor compounds was examined. This dual parameter equation describes satisfactorily the essential features of the stabilities of the donor-acceptor structures.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300731
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  • 175
    Digitale Medien
    Digitale Medien
    Flash Pyrolysis of 1,1,1-Trimethyltetrasilane - Evidence for the Formation of Dibridged Si2H2 (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1043-1046 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Matrix isolation ; Ab initio calculations ; Oligosilanes ; Silicon atoms ; Reaction mechanisms ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Pulsed flash pyrolysis of 1,1,l-trimethyltetrasilane (5) led to trimethylsilane, silane and a further species which is believed to be dibridged Si2H2 (13). Another route to 13 was found in the cocondensation of hydrogen and silicon atoms in an argon matrix at 12 K. The identification of matrix-isolated 13 is based on observed IR bands at 1475.6, 1092.8 and 890.3 cm-1. These positions are in good agreement with the ab initio calculated wavenumbers for the strongest absorptions of 13. The band shifts for the mono- and dideuterated isotopomers support this assignment.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300804
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  • 176
    Digitale Medien
    Digitale Medien
    Synthetic Routes to Transition-Metal-Substituted Pentadiynylidene Complexes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1063-1067 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Heterobimetallic complex ; Carbene complexes ; Bridging ligands ; Coupling reaction ; Alkynes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Sequential reaction of the dimethylamino(ethynyl)carbene complex [(CO)5 W=C(NMe2)C≡CH] (1) with nBuLi, CuI and BrC≡CSiMe3 affords the dimethylamino(trimethylsilylbutadiynyl)carbene [(CO)5W=C(NMe2)C≡C—C≡C—SiMe3] (2). Desilylation of 2 with KF/THF/MeOH gives [(CO)5W=C(NMe2)C≡C—C≡CH] (3). The C-stannylated carbene complex [(CO)5W=C(NMe2)C≡C—C≡CSnBu3] (4) is obtained by deprotonation of 3 with nBuLi and subsequent reaction with Bu3SnCl. Pd-catalyzed coupling of complex 4 with [ClRu(CO),Cp] affords the heterobimetallic pentadiynylidene complex [(CO)5W=C(NMe,)C≡C—C≡CRu-(CO)2Cp] (5) The analogous Fe derivative [(CO),W=C(NMe,)C≡C—C≡CFe(CO)2Cp] (6) is obtained by sequential reaction of 3 with nBuLi and [IFe(CO)2Cp] Similarly, treatment of 3 first with nBuLi and then with half an equivalent of HgCl2 affords the novel C4HgC4-bridged biscarbene complex [(CO)3W=C(NMe2)C≡C—C≡CHgC≡C—C≡CC(NMe2)=W(CO)5]( 7 ) All new compounds are stable at room temperature. Spectroscopic data suggest weak interaction of the metal centers in 5 - 7.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300807
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  • 177
    Digitale Medien
    Digitale Medien
    On the Oxenoid Character of Alkylperoxy Anions and Their Lithium Compounds: A Combined Mass-Spectrometric and Theoretical Investigation (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1085-1097 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Mass spectrometry ; Peroxides ; Oxenoids ; Density functional theory ; Kinetic energy release ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A combined mass-spectrometric and theoretical approach has been used for an investigation of the gas-phase chemistry of two representative alkylperoxy anions. Metastable CH3OO- ions undergo unimolecular loss of molecular hydrogen and formaldehyde yielding HCO-2 and OH-, respectively. The observed reactivity is in pleasing agreement with calculations of the [C,H3,O2- and [C,H,O2]- potential-energy surfaces at the BECKE3LYP/6-311+ + G** level of theory. Upon exhaustive methylation of the α-position as in t-C4H9OO- anions, the reactivity switches completely to an elimination of (CH3)2C=CH2 giving rise to the formation of HOO-. The results obtained for the “bare” alkylperoxy anions are used for the analysis of the EI mass spectrum of (t-C4H9OOLi)12 dodecamers, which thermally decompose in the inlet system at a probe temperature of ca. 130°C. The decomposition is rationalized by a mechanism involving nucleophilic attack of one t-C4H9OOLi subunit on the oxenoid oxygen atom of a second t-C4H9OOOLi moiety. This reaction may produce t-C4H9OOOLi trioxy species as intermediates, which rapidly decompose to singlet dioxygen and t-C4H9OLi.
    Zusätzliches Material: 4 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300810
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  • 178
    Digitale Medien
    Digitale Medien
    A Decavandate Sandwiched by Diprotonated Cryptands-222: Model for the Vanadate-Ionophore Interaction (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1123-1127 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Vanadium ; Cryptands ; Ionophors ; Phosphatases ; Decavanadate ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Treatment of a C222-vanadyl-AMP complex (C222 = cryptand-222, AMP = adenosine monophosphate) with Me2NH in the presence of air yielded centrosymmetric dihydrogen-decavanadate H2V10O428, sandwiched by two diprotonated C222 molecules. An X-ray crystal-structure analysis was performed of this compound with the overall composition [C222(H+)2]2[H2V10O28] · 2 1/2, H2O. Protonation sites in the anion are μ2-oxygen atoms linking two different vanadium centres. Protonation sites at the cryptand are the nitrogen and/or oxygen atoms of one of the -[CH2]2O[-CH2|2O|CH2]- bridges. The relevance of the compound for the stabilisation and transport of the kinase and phosphatase inhibitor decavanadate by biogenic ionophores is addressed.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300814
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  • 179
    Digitale Medien
    Digitale Medien
    Subsite-Specific Reactions of a Cyclotriveratrylene [4Fe-4S] Cluster Complex (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1151-1157 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Iron-sulfur clusters ; S ligands ; Cyclotriveratrylene ; Subsite-specific reactions ; Electrochemistry ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Ligand exchange reactions are carried out exclusively at the unique iron site of a subsite-differentiated cyclotriveratrylene [4Fe-4S] cluster complex. The effect of a variety of thiolate, phenolate, bidentate, and bridging ligands on the redox potential of the subsite-differentiated [4Fe-4S] cluster complex is studied and compared with the effects of such ligands on an [Fe4S4C14]2- cluster. The redox potential can be modulated within the range of -1.60 to -1.80 V (vs. Fc0/+) by varying the ligand. The introduction of an electron releasing substituent shifts the redox potential to more negative values, whereas an electron withdrawing substituent has the opposite effect. A linear relationship exists between the number of substituted sites and the reduction potential of the cluster.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300819
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  • 180
    Digitale Medien
    Digitale Medien
    The Molecular Structures of Tetra(amino)silanes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1167-1174 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Silicon ; Configuration determination ; Aminosilanes ; Tetra(amino)silanes ; Molecular conformation ; Conformation analysis ; Nitrogen ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: In a search for crystalline homoleptic tetra(amin)silanes with (mirror)-symmetrical NR2 substituents, tetrakis( 1-pyrrolidinyl)silane (1) was prepared by an improved synthetic route, and tetrakis(morpholino)silane (2) was synthesized from SiBr4 and morpholine/Li-morpholide via the intermediate BrSi[N(CH2CH2)2O]3 (4). With SiCl4 only the monochloro stage, 3, is reached. Tetrakis(4-methyl-1-piperazinyl)silane (5) was prepared similarly, using 4-methylpiperazine. With (CH2)6NH or (CH2)6NLi and SiBr4 only [(CH2)6N]3SiBr (6) was obtained. The structures of 1, 2 and 5 were determined by single-crystal X-ray diffraction. While compound 1 has an irregular molecular geometry following no symmetrical pattern, molecules of 2 and 5 have similar structures with almost superimposable Si(NC2)4 cores of approximate D2d symmetry. The overall molecular symmetry of 2 is reduced only by incongruous folding of the heterocycles, which are all in a chair conformation. The core structures of 2 and 5 are in excellent agreement with the results of density function calculations for Si(NH2)4. Si(NMe2)4 (the crystal structure of which could not be determined) was converted into (Me2N)3SiO-SO2CF3 (7) by treatment with two equivalents of triflic acid. Reaction of 7 with 1-naphthylamine/triethylamine affords (Me2N)3SiNHC9H7 (8). With 2,4-difluoroaniline/NEt3 the analogous derivative (Me2N)3SiNHC6H3F2 (9) is obtained, but with 4-bromoaniline the product is a silane with the ligands redistributed to give (Me2N2),Si(NHC6H4Br), (10), the structure of which was also determined. It has a non-standard geometry with very flat nitrogen pyramids at all four substituents.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300821
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  • 181
    Digitale Medien
    Digitale Medien
    Organometallic Chemistry sans Organometallic Reagents: Modulated Electron-Transfer Reactions of Subvalent Early Transition Metal Salts (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1175-1187 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Low-valent compounds ; Titanium ; Chromium ; C-C coupling ; Cleavage reactions ; Hydrido complexes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The potential of low-valent, early transition-metal reagents as selective reductants in organic chemistry has been foreshadowed by intensive research on the ill-defined and heterogeneous subvalent titanium intermediates generated in the McMurry reaction and its numerous variants. As part of the long-term research effort to develop soluble, well-defined transition-metal reductants of modulated and selective activity toward organic substrates, the THF-soluble reductant, titanium dichloride, has been throughly examined, as well as the analogous ZrCl2 and HfCl2 reagents, all of which are readily obtainable by the alkylative reduction of the Group tetrachloride by butyllithium in THF. Noteworthy is that such interactions of MCl4 with butyllithium in hydrocarbon media lead, in contrast, to M(III) or M(IV) halide hydrides. Analogous alkylative reductions in THF applied to VCl4, CrCl3, and MoCl5 have yielded reducing agents similar to those obtained from Mcl4 but gradated in their reactivity. Such reductants have proved capable of coupling carbonyl derivatives, benzylic halides, acetylenes and certain olefins in a manner consistent with an oxidative addition involving a two-electron transfer (TET). Such a reaction pathway is consistent with the observed stereochemistry of pinacol formation from ketones and for the reductive dimerization of alkynes. In contrast of the reaction of CrCl3 with two equivalents of butyllithium, which leads to a CrCl intermediate, the interaction of CrCl3 in THF with four equivalents of butyllithium at -78°C yields a reagent of the empirical formulation, LiCrH4.2LiCl.2 THF, as supported by elemental and gasometric analysis of its protolysis. This hydridic reductant cleaves a wide gamut of s̰ carbon-heteroatom bonds (C-X, C-O, C-S and C-N), towards which the CrCl reductant is unreactive. The type of cleavage and/or coupled products resulting from the action of “LiCrH4” on these substrates in best understood as arising from single-electron transfer (SET). In light of the aforementioned findings, the gradated reducing action noted among TiCl2, HfCl2 and CrCl, as well as the contrasting reducing behavior between CrCl and LiCrH4, there is no doubt that future research with early transition metals will continue to yield novel reductants of modulated and site-selective reactivity.
    Zusätzliches Material: 3 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300903
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  • 182
    Digitale Medien
    Digitale Medien
    2,4-Diphosphoranediyl-1,3-diphosphetanes (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1519-1527 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Phosphorus ; Heterocycles ; Phosphorus ylides ; Phosphoranediyl ; Phosphonio substituents ; P-Cl bond dissociation ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The 1,3-dichloro- and 1,3-dibromo-substituted title compounds 5b, c result from the condensation of triphenylphosphonium-bis(trimethylsily1)methylide 1 with PC13 and PBr3. The chloro derivative 5b undergoes a variety of single and double substitution reactions, of which some have merely been tested and others have been made preparative use of. The substitution of one chloride by an ylidyl, amino, phosphino, or metal carbonyl group is accompanied by the spontaneous dissociation of the other P-CI bond to yield the, 1,3-diphosphetenium chlorides 14/15, 19, 31 and 36, respectively. In other cases (9, 27, 32) dissociation can be achieved by means of a Lewis acid. Protonation of 5b occurs at the carbon ring members; methylation and formation of transition metal complexes occurs at a phosphorus ring member. PCl3 degrades the four-membered ring of5b or enlarges the ring to yield 3,5-diphosphoranediyl-l,2,4-triphospholane derivatives 39, 40, 42.
    Zusätzliches Material: 3 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301027
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  • 183
    Digitale Medien
    Digitale Medien
    Synthesis of Novel Optically Active Tin Hydrides Containing Chiral Ligands (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1539-1546 
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    ISSN: 0009-2940
    Schlagwort(e): Chiral tin hydrides ; Chiral hydrogen donors ; Tin ; Ligand effects ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The synthesis of the chiral tin bromides 1-4 and hydrides 5-8, containing the potentially bidentate, optically active 2-[ (1 S/R)- 1 -dimethylaminoethyl]phenyl and 2 -[( 1 S) - 1 -dimethylamino-2,2-dimethylpropyl]phenyl ligands, is reported. The tin hydrides 5-8, with the tin atom as the stereogenic centre, were isolated as diastereomeric mixtures with diastereomeric ratios of dr = 50:50 up to dr = 80:20. The absolute configuration of ( - ) - (1 S)- 1 - (2-bromophenyl) -2,2-dimethylpropylamine [(S)-10] was determined by single-crystal X-ray structure analysis.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301030
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  • 184
    Digitale Medien
    Digitale Medien
    Masthead (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997) 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301101
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  • 185
    Digitale Medien
    Digitale Medien
    Cobalt Phthalocyanine Derivatives Supported on TiO2 by Sol-Gel Processing. Part 1: Preparation and Microstructure (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1585-1589 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Phthalocyanines ; Sol-gel processes ; Titanium alkoxides ; Supported catalysts ; Heterogenous catalysis ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Cobalt(II) 2,9,16,23-tetrasulphophthalocyanine and cobalt(II) 2,9,16,23-tetra(chlorosulphonyl)phthalocyanine were supported on TiO2 by reaction of the phthalocyanines with Ti(OR)4 followed by sol-gel synthesis. The thus obtained solid materials are stable in sulfide-containing media and are therefore suitable as catalysts for HS oxidation. The structure of the samples was characterized by electron microscopy diffraction. The morphology of the matrix strongly depends on the cobalt phthalocyanine derivative. The pathalocyanines in the titania matrices are monomeric or dimeric depending both on the type of substituents of the CoPc derivative and on the titanium alkoxide used as precursors.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301106
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  • 186
    Digitale Medien
    Digitale Medien
    Reversible Rearrangements of Chlorophosphane-Dichlorogermylene Ylides to Trichlorogermylphosphanes  -  Structure Determination of a Tetranuclear Bis(chlorophosphane)bis(trichlorogermylphosphane) Silver Bromide Complex (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1619-1623 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Dichlorogermylene ; Trichlorogermylphosphanes ; Insertion ; Silver bromide complex ; Carbene homologues ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Chlorophosphanes RR'PCl (1a: R,R' = 1b: R = tBu, R' = iPr, 1c: R = iPr, R' = Et2N, 1d: R = Et2N react with the dichlorogermylene dioxane complex 2 furnishing trichlorogermylphosphanes RR'PGeCl3 4a-d. In the cases of 1c/4c and 1d/4d the insertion reaction remain incomplete; similarly, 4a always contains, shortly after isolation in pure state, small amounts of 1a that can be detected by NMR. A provided by the reaction of trichlorosilylphosphane tBu(Et2N)PSiCl3 (5d) with GeCl4. The alkyl(dialkylamino) trichlorogermylphosphane 4d exists only in an equilibrium with chlorophosphane 1d, which coordinates GeCl2 leading to the dichlorogermylene complex 3d. A 1:1 mixture of 4a with 1a is formed by the novel cleavage (“chlorogermylation”) of the P-P bond of tetraisopropyldiphosphane with germanium tetrachloride. Di-tert-butyl(trichlorogermyl)phosphane 4e (R, R' = tBu) reacts with silver bromide providing a crystalline silver complex 7. A structure determination by X-ray diffraction reveals that 7 is [Ag4Br4(tBu2PCl)2(tBu2PGeCl3)2]. 2C7H8. Two of the Ag atoms of the cubane-like (AgBr)4 core of 7 are coordinated by chlorophosphane 1e, the other two by trichlorogermylphosphane 4e.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301110
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  • 187
    Digitale Medien
    Digitale Medien
    Formation of the Cationic [(2-Aminoethenyl)carbine]iron Complexes by Treatment of (2-Methoxyethenyl)carbene Complexes with Primary Amines:Synthesis and Characterisation (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1647-1654 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Iron ; Carbene complexes ; (2-Methoxythenyl)methoxycarbene complexes ; Aminolysis ; (2-Aminoethenyl) methoxycarbene complexes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Cationic (2-methoxyethenyl)methoxycarbene iron complexes 2, [Cp(CO)2Fe(C(OMe)CH=CR(OMe))+][PF6-], are obtained by the addition of methanol to the corresponding (alkynyl)-methoxycarbene complexes 1, [Cp(CO)2Fe(C(OMe)C≡CR)+][PF6-]. Primary amines, H2NR', react with these 1,3-dimethoxy-substituted (alkenyl)carbene complexes, 2, through an addition/elimination process to yield cationic (2-aminoethenyl)methoxycarbene iron complexes, 3, [Cp(CO)2Fe(C(OMe)CH=CR(NHR'))+][PF6-] in an isolated yield of 71-90%. The complexes 3a-c were characterized by X-ray structural analyses. Thus, previously isolated products, from the reaction, of the (alkynyl)methoxycarbene complexes 1a and 1c, with aniline at room temperature, are assigned to the structures 3c and 3e. The spectroscopic and structural data obtained are discussed.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301115
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  • 188
    Digitale Medien
    Digitale Medien
    1,2-FDTA: A Ferrocene-Based Redox-Active EDTA Analogue with a High Ca2+/Mg2+and Ca2+/Sr2+ Selectivity in Aqueous Solution (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1405-1409 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Ferrocenes ; EDTA ; Cyclic voltammetry ; Alkaline earth metals ; Potentiometry ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: 1, 2-Ferrocenemethylenediyldiamino tetraacetate (1,2-FDTA) is a redox-active relative of EDTA and was synthesized in the reaction of 1,2-bis(chloromethyl)ferrocene with iminodiacetate methyl ester followed by cleavage of the ester with methanolic KOH. Potentiometric determination of the stability constants of the complexes of 1,2-FDTA with the alkaline earth metal ions showed this ligand to display a higher Ca2+/Mg2+ and Ca2+/Sr2+ selectivity (Ca2+ log K = 6.56, Mg2+ log K = 4.65, Sr2+ log K = 3.32) than EDTA itself. The redox potential of 1,2-FDTA-Ca2+ determined in aqueous solution by cyclic voltammetry was found to be anodically shifted by +50 mV with respect to that of the calcium free complex. Consequently the redox-inactive calcium can be determined electrochemically in aqueous solution with a high selectivity with respect to the other alkaline earth metal ions.
    Zusätzliches Material: 5 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301008
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  • 189
    Digitale Medien
    Digitale Medien
    Multiple Bonds between Main-Group Elements and Transition Metals, CLXV. Rhenium(V) Oxo Complexes with Bidentate Schiff Bases: Structures and Catalytic Applications (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1427-1431 
    Details
    ISSN: 0009-2940
    Schlagwort(e): N. Ligands ; O ligands ; Rhenium ; Structure elucidation ; Ligand effects ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Reaction of [NBu4][ReOCl4] (1) with bidentate salicylidene amine ligands (salen = HL) (2a-c) leads to the formation of monomeric octahedral rhenium (V) compounds of formula [ReOCl (L)2] (3a-c). Spectroscopic date indicate asymmetric arrangement of the ligands in the complexes. This is confirmed by the X-ray crystal structures of 3b and 3c. Complexes 3a, b have been tested as catalysts for the epoxidation of cyclooctene. No evidence for decomposition for decomposition of the catalysts is observed during the reaction (as in the case for tri-and tetra-dentate salen complexes). No undesired byproducts are formed in the catalytic reactions.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301012
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  • 190
    Digitale Medien
    Digitale Medien
    Tetraphenyl rac-3,3,7,7-Tetramethyl-trans-5 palladatricyclo[4.1.0.02,4]-heptane-1,2,4,6-tetracarboxylate: A New PTH Derivative and the First X-ray Crystallographic Study of a Bis(acetone)palladium(II) Complex (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1457-1459 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Acetone complexes ; Cyclooligomerizations ; Cyclopropenes ; Metallacycles ; Palladium ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The title compound rac-9 and its bis(acetone) complex rac-10 were prepared, and the latter investigated by X-ray structure analysis. rac-10 proves that the coordination of the weak donor acetone, an easily substitutable ligand in PTHs and related compounds, is an essential point for dissolving these coordination polymers, and thus allowing catalysis reactions in such solvents. Furthermore rac-10 shows only a small deviation from the square-planar coordination expected for Pd11. This indicates that the strong deviation from planarity observed in complexes with more sterically demanding, bidentate ligands is caused by steric interactions with the substituents on the PTH, rather than by electronic effects.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301016
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  • 191
    Digitale Medien
    Digitale Medien
    An Ylide-Substituted Tetraphosphene, Cyclotetraphosphane, and Bicyclotetraphosphane (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1801-1805 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Phosphene ; cyclophosphane isomerism ; Phosphorus Ylides ; NMR spectroscopy ; Structure elucidation ; Transanular interaction ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reaction of two specific ylidyl dichlorophosphanes, Ph3P=CR-PCl2, with P(SiMe3)3 yields the ylidyl trimethylsilyl diphosphenes Ph3P=CR.P=P-SiMe3 as primary products which form two different types of dimers: the cyclotetraphosphane 9 (R = SiMe3), and the tetraphosphene 10 (R = 2,6-Cl, 2,/C6H3). The latter compound is readily converted to the bis(ylidyl)biocyclotetraphosphane 11. The molecular structures of 9 and 11 allow a strong transanular interaction between teh ylide-substituted phosphorus atoms, which results in very large two-bond coupling constants (2Jpp = 184 and 332 Hz respectively). The central P bond in 11 is relatively long (220.7 pm); quantum chemical calculations show the lengthening to be a consequence of the perpendicular orientation of the ylidic donor p-orbital.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301215
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  • 192
    Digitale Medien
    Digitale Medien
    A Novel Stoichiometry for Chlorogold(I) Complexes: Structure of L4Au3Cl3(L =pyrrolidine) (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1813-1814 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Amines ; Gold(I) ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reaction between (tht)AuCl (tht = tetrahydrothiophene) and neat pyrrolidine (L) leads to the compound L4Au3Cl3. An X-ray structure determination reveals the presence of molecules LAuCl and ions L2Au+ and Cl-, in the ratio 2:1:1. The packing is characterised by Au.Au contacts and N-H-Cl-hydrogen bonds.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301217
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  • 193
    Digitale Medien
    Digitale Medien
    Preparation, Properties, and Reactions of Metal-Containing Heterocycles, XCVII - Differently Substituted Benzomolybdacrown Ethers and Their Capability of Including Alkali Metal CationsDedicated to Professor Achim Müller on the occasion of his 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1815-1823 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Macrocycles ; Benzomolybdacrown ethers ; Host-guest chemistry ; Stability constants ; NMR titration ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reaction of the diphosphanes 2a-i with (OC)4Mo(nbd) under high dilution conditions affords the mononuclear benzomolybdacrown ethers cis-(OC)4Mo{1,2-, 1,3-, 1,4-[PH2PCH2(CH2OCH2)πCH2]2C6H4-P, P′] (3a-i) (n = 1, 2). On the basis of the 31P nucleus the inclusion behavior of the molydacycles 3a-i toward the alkali metal salts LiBF4 and NaBPh4 was investigated with the aid of a NMR titration technique by using the program EQNMR. Only 3dshows an interaction with the alkali metal cation Na+ forming a 1:1 and 2:1 complex (3d/cation) while no interaction with Li+ could be detected. The molecular structures of 3a and 3d were elucidated by X-ray structural analyses. Complexes 3a and 3d crystallize in the monoclinic space groups P21/c and P21/n with Z = 8 and 4, respectively.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971301218
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  • 194
    Digitale Medien
    Digitale Medien
    Hexahydro-closo-hexaborane as a Ligand in Coordination Compounds: Syntheses and Crystal Structures of [M2(μ-bis-η3-B6H6)(PPh3)2] )M = Cu, Au) (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 405-408 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Hexahydro-closo-hexaborates ; Boron ; Bridging ligands ; NMR spectroscopy ; Gold ; Copper ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: By reaction of (PPh3)3 CuCl and PPh3AuCl with [B6H6]2- in organic media, dinuclear complexes are formed containing the hexaborate as a bridging ligand coordinated to the metal centers by opposite B3 facets of the B6 cluster in a trihapto mode. This is verified by single-crystal X-ray structural analysis of the isotypical (Paā) compounds [Cu2μ-bis-η3-B6H6)(PPh3)2] (1) and [Au2(μ-bis-η3-B6H6)(PPh3)2)] (2) which showed the metal centers to be very close to the B3 plane [1.92 (1), 2.10 (2) Å. The 11B NMR spectra of the two compounds feature doublets, at δ= -15.32 in 1 and at -11.51 in 2, which are significantly shifted downfield in comparison to [B6H6]2- (δ= -17.2).
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300315
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  • 195
    Digitale Medien
    Digitale Medien
    Crown Thioether Chemistry: Novel Silver(I) Complexes of 1,3-Dithiole-Annelated 1,4,7-Trithiacyclononane (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 425-429 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Silver complexes ; Crown compounds ; Thioethers ; 1,3-Dithioles ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The coordination chemistry of two crown thioethers 2,5,8,10,12-pentathiabicyclo[7.3.0]dodeca-1)9)-ene-11-thione (L) and -11-one (L') with Ag1 has been investigated by structural methods. Both thioethers act as tridentate ligands coordinating the silver ion in a trigonal fashion. In the case L, the 11- thione sulfur is coordinated additionally by another silver ion, to yield a polymeric chain with a distorted-tetrahedral geometry about the metal ion. Despite differing only in its carbonyl chalcogen, L' forms six-coordinated, monomeric complexes.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300319
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  • 196
    Digitale Medien
    Digitale Medien
    Unsymmetric Dinucleating Ligands for Metallobiosite Modelling (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 433-442 
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    ISSN: 0009-2940
    Schlagwort(e): Metallobiosites ; Metalloproteins ; Metalloenzymes ; Dinucleating ligands ; Transition metals ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Awareness of the asymmetric nature of numerous dinuclear metallobiosites and of the ability of the individual metal ions to have quite distinct roles in the functioning of the metalloenzyme concerned has led to a search for carefully designed unsymmetric dinucleating ligands that will give dinuclear complexes capable of acting as models for the metallobiosites. This review surveys progress made in the design and synthesis of complexes capable of serving as models for donor atom, coordination number and geometric asymmetries found at dinuclear metal centres.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300402
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  • 197
    Digitale Medien
    Digitale Medien
    Synthesis of the Hexakis[(triphenylphosphane)gold(I)]methanium(2+) Cation from Trimethylsilyldiazomethane; Crystal Structure Determination of the Tetrafluoroborate Salt (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 111-114 
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    ISSN: 0009-2940
    Schlagwort(e): Gold clusters ; Silyldiazomethane ; Auration ; Interstitial carbon atom ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A new synthetic route to the bis(tetrafluoroborate) salt of the hexakis[(triphenylphosphane)gold(I)]methanium dication has been opened up through the reaction of trimethylsilyldiazomethane and tris[(triphenylphosphane)gold(I)]oxonium tetrafluoroborate in dichloromethane. Yields are close to 65% if the reaction is carried out in the presence of triethylamine as a base. The process is a sequence of desilylation, deprotonation and deazotation reactions at the carbon function of the diazomethane, as shown by the detection of intermediates. The crystal structure of the title compound (with three equivalents of crystal dichloromethane) has been determined in a single-crystal X-ray study. The dication has no crystallographically imposed symmetry, but the core is a distorted, carbon-centered octahedron of gold atoms. This result confirms the data from previous structural studies of salts with other anions and interstitial solvents.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300118
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  • 198
    Digitale Medien
    Digitale Medien
    The Gas-Phase Structure of Trifluoromethyl Vinyl Sulfide, CF3SC(H)=CH2Dedicated to Prof. Dr. mult. Dr. h.c. Alois Haas on the occasion of his 65th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 131-134 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Trifluoromethyl vinyl sulfide ; Gas-phase structure ; Electron diffraction ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The geometric structure of trifluoromethyl vinyl sulfide, CF3SC(H)=CH2, was determined by gas electron diffraction and ab initio calculations (HF/3-21G* and MP2/6-31G*). A single conformer with a dihedral angle φ(C=C-S-C) = 129(4)° is present. The conformational properties are compared to those of the parent compound, CH3SC(H)=CH2, and of the perfluorinated species CF3SC(F)=CF2.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300122
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  • 199
    Digitale Medien
    Digitale Medien
    Enantioselective Catalysis, XIVPart XIII: U. Nagel, H. G. Nedden, Chem Ber. 1997, 130,385-397.Asymmetric Grignard Cross-Coupling Reaction: An Investigation of the Factors Influencing Asymmetric Induction with a New Type of Pyrrolidinephosphane (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 535-542 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Cross-coupling ; Grignard reactions ; Pyrrolidinephosphanes ; Asymmetric amplification ; Gas chromatography ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: An investigation of the asymmetric synthesis of 3-phenyl-1-butene by the Grignard cross-coupling reaction is presented. The reaction is catalysed by nickel complexes of bisphosphane and 3-diphenylphosphanylpyrrolidine-type ligands. A comparison of the results obtained with our P,N monophosphane ligands with those obtained with the most effective known amino acid derived P,N ligands shows a similar enantioselectivity but an inverse sense of optical induction. An X-ray structural analysis of the 1-phenylethyl Grignard compound is reported. Quantitative analysis and the determination of enantiomeric composition of the catalytic samples is accomplished using a novel enantioselective GLC separation. Compared to the popular model reaction that uses a chloride-containing Grignard compound and vinyl bromide as starting compounds, we obtain improved enantioselectivities of P,N monophosphane catalysts by substituting vinyl bromide with vinyl chloride. With two of the new P,N ligands we find a nonlinear dependence of enantioselectivity on the enantiomeric purity of the ligands (asymmetric amplification). Catalytic results subject to such nonlinear effects show a dependence on the ligand to nickel ratio.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300414
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  • 200
    Digitale Medien
    Digitale Medien
    Atropisomeric Binaphthalene-Core Phosphacyclic Derivatives in Coordination Chemistry and Homogeneous Catalysis (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 543-554 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Phosphorus heterocycles ; Binaphthophosphole ; Atropisomerism ; Binaphthophosphepine ; Hydroformylations ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Binaphthophospholes and binaphthophosphepines have recently been synthesized. These are the first representatives of a new class of chiral ligands that include within the same structure an endocyclic phosphorus donor, a local C2 symmetry and an axially chiral core. In this review we discuss the synthesis, chemical behaviour and first applications in asymmetric catalysis of these novel derivatives.
    Zusätzliches Material: 4 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19971300503
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