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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1959-1967 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Structure of Lithium Complexes with pentahapto-Bonded Tris(trimethylsilyl)cyclo-pentadienyl LigandsReaction of tris(trimethylsilyl)cyclopentadienyllithium (2) with the nitrogen bases quinuclidine, tetramethylethylenediamine, and pentamethyldiethylenetriamine leads to the isolation of the crystalline, air-sensitive 1:1-adducts 3, 4, and 5, resp., which are monomeric in the gas phase, in solution, and in the solid state. X-Ray structure determinations show that in 3-5 the cyclopentadienyl ring is pentahapto-bonded to the lithium atom. The bonding in these π-complexes is discussed; the complex 3 fulfills the criteria for a nido-cluster.
    Notes: Umsetzung von Tris(trimethylsilyl)cyclopentadienyllithium (2) mit den Stickstoffbasen Chinuclidin, Tetramethylethylendiamin und Pentamethyldiethylentriamin führt zur Isolierung der kristallinen, luftempfindlichen 1:1-Addukte 3, 4 und 5, die in der Gasphase, in Lösung und im festen Zustand monomer vorliegen. Kristallstrukturuntersuchungen zeigen, daß in 3-5 der Cyclopentadienylring pentahapto an das Lithiumatom gebunden ist. Die Bindungsverhältnisse in diesen π-Komplexen werden diskutiert; der Komplex 3 erfüllt die Kriterien für einen nido-Cluster.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 81-85 
    ISSN: 0009-2940
    Keywords: Aluminium-aluminium bond ; Insertion of trimethylsilyl azide ; Trimeric dialkylaluminium azide ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of R2Al—AlR2 (R = CH(SiMe3)2) with Trimethylsilyl Azide  -  Insertion into the Al—Al Bond and Formation of a Trimeric Dialkylaluminium AzideTetrakis[bis(trimethylsilyl)methyl]dialuminium(4) (1) reacts with trimethylsilyl azide under insertion of one nitrogen atom into the Al—Al bond. As shown by NMR spectra and crystal structure the product contains three and four coordinated Al atoms due to the coordination of the α-nitrogen atom of the azide group to one of the Al atoms. An electronically delocalized N3-system is formed with a N—N bond length of 132.0 pm and a bond order of 1.5 for both N—N bonds. With an excess of trimethylsilyl azide further reaction is observed only under mild irradiation conditions with an exchange of the azide group between Si and Al and formation of Me6Si2 and the dialkylaluminium azide 3, which is better synthesized by the reaction of Me3Si—N3 with Cl—Al[CH(SiMe3)2]2. The sterically highly shielded aluminium azide 3 is a trimer in the solid state showing a non-planar 12-membered Al3N9 heterocycle with short N—N bonds (114 pm).
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0009-2940
    Keywords: Germanium ; Digermenes ; Tin ; Germylenes ; Stannylenes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Treatment of GeCl2 · dioxane with the Grignard reagent RMgBr (R=2-tBu-4,5,6-Me3C6H) furnishes the tetraaryldigermene R2Ge=GeR2 (8). X-ray structure-analysis of 8 reveals a short Ge=Ge double bond, a nearly planar environment of both germanium atoms and extremely widened C—Ge—C angles of 128°. In solution, 8 dissociates into two germylene molecules R2Ge, which can be trapped with oxygen or by [4+1] cycloaddition reactions with 1,4-dihetero-1,3-dienes. A similar cycloadduct of a stannylene wa obtained by thermolysis of (R′2Sn)3 (R′=2,4,6-iPr3C6H2), in the presence of a 1,4-diazabutadiene and characterized by an X-ray structure-analysis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 2325-2327 
    ISSN: 0009-2940
    Keywords: Diselenide, torsion angle/NMR, 77Se/Selenenyl halide ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bis[tris(trimethylsilyl)methyl] Diselenide: An Unusual Diselenide with Sterically Enforced trans-C2h ConformationDeselenation of bis[tris(trimethylsilyl)methyl] triselenide (1) with copper occurs with formation of bis[tris(trimethylsilyl)-methyl] diselenide (2) and minor amounts of 3,3,5,5-tetrakis(trimethylsilyl)-1,2,4-triselenolane (3). The structures of 2 and 3 have been studied by multinuclear NMR spectroscopy and by X-ray crystallography. The C—Se—Se—C moiety of 2 adopts an unusual antiperiplanar conformation. Cleavage of the Se — Se bond by iodine providing iodo[tris(trimethylsilyl)-methyl]selane (5) is complete with 2, but reversible with 1.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0009-2940
    Keywords: Chalcogen-chalcogen bonds ; Selenium ; Selenide (2,4,6-tri-tert-butylphenyl)- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Properties of Chalcogen-Chalcogen Bonds, XV1). - Lithium 2,4,6-Tri-tert-butylphenylselenide: Synthesis, Structure, and Reactions with Formation of Se - P, Se - C, Se - Si, Se - Sn, and Se - Au BondsBis(2,4,6-tri-tert-butylphenyl)diselenide (1) is reduced by lithium triethylhydridoborate to give lithium 2,4,6-tri-tert-butyl-phenylselenide (2) in high yield. 2 crystallizes with three molecules of tetrahydrofuran coordinated to lithium ([2(THF)3] ≡ 2a, space group P&1macr; Z =4). The monomeric compound 2a contains four-coordinate lithium bonded to two-coordinate selenium. 2 (LiSeR) reacts with the nonmetal and metal halides tBu2PCl, CH2Cl2, Me3SiCl, Me3SnCl, and Ph3PAuCl to give tBu2PSeR (3), RSeCH2Cl (4), (RSe)2CH2 (5), Me3SiSeR (6), Me3SnSeR (7), and the novel gold(I) selenophenolate derivative Ph3PAuSeR (8)(R = 2,4,6-tri-tert-butylphenyl).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0009-2940
    Keywords: Stannylene, bis(2,4,6-triisopropylphenyl)- ; Distannene, tetrakis(2,4,6-triisopropylphenyl)- ; 1,2-Distannacyclobutene derivative ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Compounds of Germanium and Tin, 10[1].  -  Thermolysis of a Cyclotristannane: Stannylene versus Distannene ReactionsHexakis(2,4,6-triisopropylphenyl)cyclotristannane (1), first described by Masamune and Sita, is easily accessible by treatment of tin(II) chloride with 2,4,6-triisopropylphenylmagnesium bromide. The equilibrium between 1 and its cleavage products bis(2,4,6-triisopropylphenyl)stannylene (2) and tetrakis(2,4,6-triisopropylphenyl)distannene (3) in toluene has been followed by 119Sn-NMR spectroscopy at elevated temperatures. Stannylene 2 can be trapped by open-chain or cyclic diketones as well as by 1,3-dienes. Reaction of 3 with phenylacetylene proceeds in a [2 + 2] fashion to provide the 1,2-distannacyclobutene derivative 5 whose structure was confirmed by X-ray crystallography.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 761-766 
    ISSN: 0009-2940
    Keywords: Tellurium compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cleavage of Bulky Diaryl Ditellurides with Bromine and Iodine; Crystal Structure of Et4N+ 2,4,6-(i-C3H7)3C6H2TeI-2Bis(2,4,6-triisopropylphenyl) ditelluride (1a), obtained from 2,4,6-triisopropylphenylmagnesium bromide with tellurium followed by oxidation with oxygen, and bis(2,4,6-tri-tert-butylphenyl) ditelluride (1b) react with equimolar amounts of bromine and iodine to provide new monomeric arenetellurenyl halides 2,4,6-R3C6H2TeX (2a, b, 3a, b: R = i-C3H7, t-C4H9; X = Br, I). Both tellurenyl iodides are thermally more stable than the corresponding bromides. Green 2,4,6-(i-C3H7)3C6H2TeI (3a) reacts with Et4N+I- to give the stable, red adduct Et4N+ 2,4,6-(i-C3H7)3C6H2TeI-2 (4a). An X-ray crystal structure determination of 4a revealed a T-shaped structure of the hypervalent aryldiiodotellurate(II) anion. Iodide-ion transfer between aryldiiodotellurate(II) and arenetellurenyl iodide is a fast process (1H-NMR time scale). 125Te-NMR data of this anion and of tellurenyl halides are compared with those of the ditellurides and of lithium benzenetellurolates (LiTeR·(THF)x).
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0009-2940
    Keywords: Disilenes ; Organosilicon compounds ; 1,2,3-Oxadisiliranes ; Dioxadisiletanes ; Cycloaddition reactions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of the unsymmetrically substituted disilene R2Si=SiR′2 (4; R = 2,4,6-Me3C6H2, R′ = 2,4,6-iPr3C6H2) with m-chloroperbenzoic acid (mCPBA) or oxygen furnished the correspondingly substituted 1,2,3-oxadisilirane 5 or 1,3,2,4-dioxadisiletane 6, respectively. The [2 + 2] and [2 + 4] Cycloaddition reactions of 4 with benzophenone and 3,5-di-tert-butyl-1,2-benzoquinone, respectively, proceeded with a high degree of regioselectivity to yield the 1,2,3-oxadisiletane 9 and the 2,3-dihydro-1,4,2,3-benzodioxadisiline 7. The latter product was isolated together with a small amount of an isomeric compound 8 in which the substituents at the silicon atoms are reversed. The molecular structures of the products 5, 6, and 7 were determined by X-ray crystallography.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 129 (1996), S. 897-901 
    ISSN: 0009-2940
    Keywords: Gallium-Gallium bond ; Isocyanide insertion ; 1,4-Diazabutadiene derivatives ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tetrakis[bis(trimethylsilyl)methyl]digallane(4) (1) reacts with tert-butyl or aryl=isocyanides [aryl = phenyl, o-methylphenyl, o-methoxyphenyl, p-methoxyphenyl) by a twofold insertion of the central carbon atoms into the Ga-Ga bond and formation of C-C single bonds. 1,4-Diazabutadiene derivatives bound to two R2Ga groups are formed (2-6), which in contrast to an aluminium analog exhibit only weak interactions between the imine nitrogen atoms and the coordinatively unsaturated gallium atoms as indicated by NMR spectroscopy and the long Ga-N distances in the molecular structures of three products: 2 (R = C6H5), 4 (R = o-MeOC6H4), and 6 (R = CMe3).
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0009-2940
    Keywords: Silicon ; Germanium ; Tin ; Carbene homologues ; Digermene ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 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.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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