- TRIHYDRIDOSILYL-TERMINATED POLYSILANES AND METHODS OF PREPARATION
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Novel trihydridosilyl-terminated polysilanes and methods for their synthesis, which are applicable to other polysilanes, are provided. The synthetic methods provide for facile preparation of products with minimal handling of pyrophoric intermediates and b
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Page/Page column 5-6
(2012/04/04)
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- Reactivity of group 4 benzamidinate complexes towards mono- and bis-substituted silanes and 1,5-hexadiene
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Zirconium and titanium bis(benzamidinate) dimethyl complexes were found to be active catalytic precursors for the oligomerization of mono- and bis-substituted silanes. The activation of such complexes, by an excess of MAO or by an equimolar amount of B(C
- Volkis, Victoria,Averbuj, Claudia,Eisen, Moris S.
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p. 1940 - 1950
(2007/10/03)
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- Electrochemical synthesis of symmetrical difunctional disilanes as precursors for organofunctional silanes
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Difunctional disilanes of the general type XR2SiSiR2X (1-5) (X = OMe, H; R = Me, Ph, H) have been synthesized by electrolysis of the appropriate chlorosilanes XR2SiCl in an undivided cell with a constant current supply and in the absence of any complexing agent. Reduction potentials of the chlorosilane starting materials derived from cyclic voltammetry measurements were used to rationalize the results of preparative electrolyses. Organofunctional silanes of the general formula MeO(Me 2)SiC6H4Y (6a-c, 7) were subsequently obtained by the reaction of sym-dimethoxytetramethyldisilane (1) with NaOMe in the presence of p-functional aryl bromides BrC6H4Y (Y = OMe, NEt2, NH2).
- Grogger, Christa,Loidl, Bernhard,Stueger, Harald,Kammel, Thomas,Pachaly, Bernd
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p. 105 - 110
(2007/10/03)
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- Dehydropolymerization of arylsilanes catalyzed by a novel silylmolybdenum complex
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A complex [MoH3[Si(Ph)[Ph2PCH2CH 2P(Ph)C6H4-o]2]] (1) can act as single-component catalyst for dehydrogenative polymerization of ArSiH 2R (Ar = Ph, p-tolyl, o-tolyl; R = H, Me) to (ArSiR)n: p- and o- tolylsilane produced the polymers of respectable molecular weights (MW of 17300 and 6700 respectively) and polymerization of secondary silane, methylphenylsilane, gave a substantial molecular weight (MW of 1750).
- Minato, Makoto,Matsumoto, Takaomi,Ichikawa, Miyuki,Ito, Takashi
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p. 2968 - 2969
(2007/10/03)
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- Rapid, highly linear-selective dehydrocoupling of phenylsilane with new group 4 metallocene-based combination catalysts
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The dehydrocoupling of phenylsilane with Cp12MCl2/Red-Al (Cp1 = C5H5 or C5Me5; M = Ti, Zr, Hf; Red-Al = Na[H2Al(OCH2CH2OMe)2/sub
- Woo, Hee-Gweon,Song, Sun-Jung
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p. 457 - 458
(2007/10/03)
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- Ansa-Metallocenes: Catalysts for the Dehydrocoupling of Hydrosilanes
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The dehydrocoupling of PhMeSiH2 to form oligomers and of PhSiH3 to form polysilanes has been performed with the precatalyst combination of 5-C5H5)2MCl2/nBuLi.
- Shaltout, Raef M.,Corey, Joyce Y.
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p. 4309 - 4320
(2007/10/02)
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- Condensation of primary silanes in the presence of Cp2MCl2/n-BuLi (M = Ti, Zr, Hf)
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The condensation of RSiH3 (R = Ph, nBu, nHex) to silicon oligomers in the presence of the catalyst precursor combination Cp2MCl2/2nBuLi (M = Ti, Zr, Hf) has been monitored by gas chromatography and the intermediate oligomers characterized by GC-MS.The average molecular weights of the isolated products from PhSiH3 depend on the catalyst and increase through the sequence, Hf nBuSiH)4H are produced in equal amounts throughout the reaction period for M = Ti but at different rates for M = Zr and only one diastereomer is observed for M = Hf.The observations are discussed in terms of chain growth through sigma-bond metathesis processes.
- Corey, Joyce Y.,Zhu, Xiao-Hong
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- Dehydrogenative polymerization of silanes to polysilanes by zirconocene and hafnocene catalysts. A new polymerization mechanism
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We have found that a number of zirconium and hafnium siyl complexes of the type Cp′2M(SiR3)R′ (Cp′ = η5-C5H5, Cp (η5-C5Me5); M = Zr, Hf; R = Me, Ph, SiMe3; R′ = Cl, alkyl, silyl) are catalyst precursors for this dehydrogenative coupling reaction and that polymer molecular weights can vary as a function of reaction conditions and catalyst. Improvement of this method relies heavily on an understanding of the polymerization mechanism, which has remained obscure. This report describes observations that suggest a mechanism for dehydrogenative silane polymerization by zirconocene and hafnocene catalysts.
- Woo, Hee-Gweon,Tilley, T. Don
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p. 8043 - 8044
(2008/10/08)
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