- DISILANE-, CARBODISILANE-AND OLIGOSILANE CLEAVAGE WITH CLEAVAGE COMPOUND ACTING AS CATALYST AND HYDROGENATION SOURCE
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The invention relates to a process for the manufacture of monosilanes of formula (I): MexSiHyClz (I), comprising: the step of subjecting a silane substrate (methyldisilanes, methyloligosilanes, or carbodisilanes) to a cleavage reaction of the silicon-silicon bond(s) or the silicon- carbon bonds in silane substrates the reaction involving a cleavage compound selected from a quaternary Group 15 onium compound R4 QX, a heterocyclic amine, a heterocyclic ammonium halide, or a mixture of R3P and RX. The starting material disilanes to be cleaved has the formula (II): MemSi2HnClo (II) The starting material oligosilanes to be cleaved have the general formula (III): MepSiqHrCIs (II I), The starting material carbodisilanes to be cleaved have the general formula (IV): (MeaSiHbCle)-CH2-(MecSiHdClf) (IV)
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Page/Page column 44
(2019/04/16)
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- Reactions of dodecamethylcyclohexasilane and polydimethylsilane with metal chlorides
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The reactions of dodecamethylcyclohexasilane and high-molecular-weight polydimethylsilane with chlorides of I, II, IV-VI and VIII Group metals at high temperature in the absence of a solvent were studied. The interaction of (Me2Si)6 with metal chlorides proceeds with the cleavage of Si-Si and Si-C bonds with the formation of chloro derivatives of linear and cyclic permethyloligosilanes. The reactions of polydimethylsilane with metal chlorides afford mixtures of α,ω-dichlorooligosilanes, Cl(Me2Si)nCl (n=2-9). The influence of the reaction conditions (temperature, reaction time and the reagent ratio) on the composition and yields of the reaction products was examined.
- Chernyavskii,Larkin,Chernyavskaya
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- Synthesis of dichloro derivatives of linear and cyclic permethyloligosilanes and cyclolinear permethylpolysilane-siloxanes and permethylpolyoxysilane based on them
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The reactions of dodecamethylcyclohexasilane with chlorides of I, II, IV-VI, and VIII Group metals were studied as a promising approach to the synthesis of functional oligosilanes. When cyclohexasilane reacts with metal chlorides without a solvent at elevated temperatures, the process is intensified and, in some cases, the selectivity of formation of chloro derivatives of linear and cyclic permethyloligosilanes increases. The cyclolinear permethylpolysilane-siloxanes were prepared by heterofunctional polycondensation of the resulting oligosilanes with bifunctional cyclic and linear permethyloligosiloxanes. Cyclolinear permethylpolyoxysilane was synthesized for the first time by the reaction of 1,3-dihydroxycyclo-hexasilane with 1,3-dichlorohexamethyltrisilane.
- Chernyavskii, A. I.,Larkin, D. Yu.,Chernyavskaya, N. A.
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p. 175 - 180
(2007/10/03)
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- Synthesis of α,ω-dichloropermethyloligosilanes by reactions of polydimethylsilane with metal chlorides
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The reactions of high-molecular-weight polydimethylsilane with metal chlorides in variable oxidation states at high temperature in the absence of a solvent afford mixtures of α,ω-dichloropermethyloligosilanes Cl(Me2Si)mCl (m = 2-9). The influence of the reaction conditions (temperature, reaction time, and the reagent ratio) on the composition and yields of the reaction products was examined.
- Chernyavskii, A. I.,Chernyavskaya, N. A.
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p. 1751 - 1753
(2007/10/03)
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- Synthesis of α,ω-dihalopermethyloligosilanes and silane-siloxane copolymers
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α,ω-Dibromopermethyloligosilanes, Br(SiMe2)nBr (n = 2-4, 6), were prepared by the reaction of dodecamethylcyclohexasilane with bromine. The reaction of (Me2Si)6 with MCl4 (M = Sn, Ti) proceeds with the cleavage of Si-Si-and Si-C-bonds with the formation of α,ω-dichloropermethyloligosilanes, Cl(SiMe2)nCI (n = 2-4, 6), and chloro derivatives of cyclohexasilane, ClmSi6Me12-m (m = 1, 2). Silane-siloxane copolymers of regular structure were obtained by heterofunctional copolycondensation of α,ω-dihalopermethyloligosilanes with 1,5-dihydroxyhexamethyltrisiloxane.
- Chernyavskii,Zavin
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p. 1449 - 1453
(2007/10/03)
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- Methylchlorooligosilanes as products of the basecatalysed disproportionation of various methylchlorodisilanes
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The methylchlorodisilanes SiCl2Me-SiCl2Me (1), SiCl2Me-SiClMe2 (2) and SiClMe2-SiClMe2 (3) disproportionate in the presence of a basic catalyst into methylchloromonosilanes and various methylchlorooligosilanes. Oligosilanes involving up to seven silicon atoms were identified by means of 29Si-, 13C-1H-NMR and GC-MS measurements. Formation of methylchlorooligosilanes is thought to take place via silylene intermediates.
- Herzog,Richter,Brendler,Roewer
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p. 221 - 228
(2007/10/03)
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- The behaviour of medium-sized permethylated cyclosilanes towards SOCl2 and SOCl2-HC(OCH3)3
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Treatment of Si6Me12 with SOCl2 in various solvents gives α,ω-dichloropermethylpolysilanes (nSi = 2,3,4,6) at temperatures above 80 deg C.In contrast to an earlier report, treatment of the α,ω-dichloropermethylpolysilanes with HC(OCH3)3 in the presence of SOCl2 does not give Si6Me12.
- Jenkner, P.K.,Spielberger, A.,Hengge, E.
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p. 161 - 164
(2007/10/02)
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- ?-BOND CONJUGATION IN POLYSILANES, A PES SCALED FREE-ELECTRON APPROACH FOR THE INTERPRETATION OF SKELETAL CLEAVAGE REACTION
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The ?-orbital energies calculated by the simple free-electron model with a parametrization procedure recently by Von Szentpaly correlate very closely with the ?-band positions of the corresponding photoelectron spectra.For the ?-orbitals of three series of molecules: H(CH2)nH (n=2-4); H(SiH2)nH (n=2-5); Me(SiMe2)nMe (n=2-4) the FEMO model yields a standard error (SE) of 0.060 eV.Compared with HMO results (LCGO, LCBO and Sandorfy C) the correlation is significantly improved.The free-electron results are more accurate than those obtained using the PPP, CNDO/2, MINDO/3, SAMO and ab initio methods.The free-electron frontier orbital densities were successfully used to account for features of the skeletal cleavage reactions of polysilanes.
- Herman, Aleksander,Dreczewski, Boguslaw,Wojnowski, Wieslaw
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