4342-61-4Relevant academic research and scientific papers
The behaviour of medium-sized permethylated cyclosilanes towards SOCl2 and SOCl2-HC(OCH3)3
Jenkner, P.K.,Spielberger, A.,Hengge, E.
, p. 161 - 164 (1992)
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.
Synthesis of α,ω-dichloropermethyloligosilanes by reactions of polydimethylsilane with metal chlorides
Chernyavskii, A. I.,Chernyavskaya, N. A.
, p. 1751 - 1753 (2002)
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.
Katalytische Hydrierung chlorhaltiger Disilane mit Tributylstannan
Herzog, U.,Roewer, G.,Paetzold, U.
, p. 143 - 148 (1995)
Partial hydrogenation of methylchlorodisilanes and hexachlorodisilane to methylchlorohydrogendisilanes and chlorohydrogendisilanes respectively, is possible by the use of tri-n-butylstannane.Electron-pair donators catalyse the hydrogenation reaction.The 29Si NMR chemical shifts and coupling constants 1JSiH of some new methylchlorohydrogendisilanes are reported.Keywords: Silicon; Catalysis; Partial hydrogenation
?-BOND CONJUGATION IN POLYSILANES, A PES SCALED FREE-ELECTRON APPROACH FOR THE INTERPRETATION OF SKELETAL CLEAVAGE REACTION
Herman, Aleksander,Dreczewski, Boguslaw,Wojnowski, Wieslaw
, p. 7 - 14 (1983)
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.
Synthesis of dichloro derivatives of linear and cyclic permethyloligosilanes and cyclolinear permethylpolysilane-siloxanes and permethylpolyoxysilane based on them
Chernyavskii, A. I.,Larkin, D. Yu.,Chernyavskaya, N. A.
, p. 175 - 180 (2002)
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.
PROCESS FOR THE PRODUCTION OF ORGANOHYDRIDOCHLOROSILANES FROM HYDRIDOSILANES
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Page/Page column 45; 46, (2019/04/16)
The invention relates to a process for the manufacture of organomonosilanes bearing both hydrogen and chlorine substituents at the silicon atom by subjecting one or more organomonosilanes to the reaction with one or more di- or carbodisilanes in the presence of one or more compounds (C) acting as a redistribution catalyst, wherein at least one of the silanes has only hydrogen and organic residues at the silicon atoms.
Disilane Cleavage with Selected Alkali and Alkaline Earth Metal Salts
Santowski, Tobias,Sturm, Alexander G.,Lewis, Kenrick M.,Felder, Thorsten,Holthausen, Max C.,Auner, Norbert
supporting information, p. 13202 - 13207 (2019/10/22)
The industry-scale production of methylchloromonosilanes in the Müller–Rochow Direct Process is accompanied by the formation of a residue, the direct process residue (DPR), comprised of disilanes MenSi2Cl6-n (n=1–6). Great research efforts have been devoted to the recycling of these disilanes into monosilanes to allow reintroduction into the siloxane production chain. In this work, disilane cleavage by using alkali and alkaline earth metal salts is reported. The reaction with metal hydrides, in particular lithium hydride (LiH), leads to efficient reduction of chlorine containing disilanes but also induces disproportionation into mono- and oligosilanes. Alkali and alkaline earth chlorides, formed in the course of the reduction, specifically induce disproportionation of highly chlorinated disilanes, whereas highly methylated disilanes (n>3) remain unreacted. Nearly quantitative DPR conversion into monosilanes was achieved by using concentrated HCl/ether solutions in the presence of lithium chloride.
Making Use of the Direct Process Residue: Synthesis of Bifunctional Monosilanes
Sturm, Alexander G.,Santowski, Tobias,Schweizer, Julia I.,Meyer, Lioba,Lewis, Kenrick M.,Felder, Thorsten,Auner, Norbert,Holthausen, Max C.
supporting information, p. 8499 - 8502 (2019/06/13)
The industrial production of monosilanes MenSiCl4?n (n=1–3) through the Müller–Rochow Direct Process generates disilanes MenSi2Cl6?n (n=2–6) as unwanted byproducts (“Direct Process Residue”, DPR) by the thousands of tons annually, large quantities of which are usually disposed of by incineration. Herein we report a surprisingly facile and highly effective protocol for conversion of the DPR: hydrogenation with complex metal hydrides followed by Si?Si bond cleavage with HCl/ether solutions gives (mostly bifunctional) monosilanes in excellent yields. Competing side reactions are efficiently suppressed by the appropriate choice of reaction conditions.
CLEAVAGE OF METHYLDISILANES TO METHYLMONOSILANES
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Paragraph 27; 28, (2019/04/16)
The invention relates to a process for the manufacture of methylmonosilanes comprising the step of subjecting one or more methyldisilanes to the cleavage reaction of the silicon-silicon bond, and optionally a step of separating the resulting methylmonosilanes.
One-Step Synthesis of Siloxanes from the Direct Process Disilane Residue
Neumeyer, Felix,Auner, Norbert
supporting information, p. 17165 - 17168 (2016/11/23)
The well-established Müller–Rochow Direct Process for the chloromethylsilane synthesis produces a disilane residue (DPR) consisting of compounds MenSi2Cl6?n(n=1–6) in thousands of tons annually. Technologically, much effort is made to retransfer the disilanes into monosilanes suitable for introduction into the siloxane production chain for increase in economic value. Here, we report on a single step reaction to directly form cyclic, linear, and cage-like siloxanes upon treatment of the DPR with a 5 m HCl in Et2O solution at about 120 °C for 60 h. For simplification of the Si?Si bond cleavage and aiming on product selectivity the grade of methylation at the silicon backbone is increased to n≥4. Moreover, the HCl/Et2O reagent is also suitable to produce siloxanes from the corresponding monosilanes under comparable conditions.
