ChemInform Abstract: Reaction of Magnesium Silicide and Silicon Tetrachloride/Trichlorosilane in the Presence of Hydrogen (original) (raw)
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Reaction of Magnesium Silicide & Silicon Tetrachloride/Trichlorosilane in Presence of Hydrogen
1988
The formation of silane (SiH.) has been observed during the reaction of silicon tetrachoride and hydrogen (SiC!. + H,) with magnesium silicide (Mg2Si) at 400-500°C. The silane formed decomposes to give silicon in the vicinity of Mg,Si charge. A mixture of trichlorosilane + H2 reacts with Mg2Si at 250°C to afford silane which has been separated and decomposed to high purity silicon. The reaction of SiHCI] + H2 with Mg,Si gives optimum conversion when SiHCI,:H, ratio is 1:4 at the reaction temperature of 250°C.
The Journal of Physical Chemistry A, 1998
A mechanism for the homogeneous gas-phase decomposition of SiHCl 3 , SiH 2 Cl 2 , and SiH 3 Cl in hydrogen is derived from the results of ab initio molecular-orbital studies. It consists of 39 reversible elementary reactions among 25 species, including pressure-dependent unimolecular decomposition of the chlorinated silanes and secondary chemistry due to reactions of SiH 2 , SiHCl, and SiCl 2 with one another and with the chlorinated silanes. Rate parameters in the mechanism have been calculated based on results of ab initio studies using transition-state theory and unimolecular rate theories. This allows us to construct a reasonably complete mechanism that provides qualitative explanations for several features of dichlorosilane decomposition that have been presented in the literature, including observations on the presence and concentrations of SiCl 2 , SiHCl, and Si atoms. Several chain reactions in which the chain carriers are divalent silicon species have been identified. S1089-5639(97)03174-5 CCC: $15.00
Organometallics, 2004
A series of multifunctional (chloromethyl)silanes have been synthesized: Cl 2 Si(CH 2 Cl) 2 (1), (MeO) 2 Si(CH 2 Cl) 2 (2), tris(chloromethyl)(2,4,6-trimethoxyphenyl)silane (3), ClSi(CH 2-Cl) 3 (4), MeOSi(CH 2 Cl) 3 (5), Si(CH 2 Cl) 4 (6), and ClCH 2 CH 2 Si(CH 2 Cl) 3 (7). The synthesis of these compounds is based on coupling reactions between (chloromethyl)lithium, generated in situ from bromochloromethane and n-butyllithium in tetrahydrofuran, and chlorosilanes. Compounds 1-7 were characterized by NMR studies (1 H, 13 C, 29 Si) and elemental analyses, and 3 and 6 were additionally studied by single-crystal X-ray diffraction. Silanes with more than one SiCH 2 Cl moiety and compounds of this type with additional Si-functional groups are of great interest for synthetic organosilicon chemistry.
Silicon Compounds: Silanes and Silicones A Survey of Properties and Chemistry
Silicon Compounds: Silanes and Silicones A Survey of Properties and Chemistry 3rd edition (Japanese), 2013
An overview of silane and silicone chemistry in 15 full chapter reviews. A register of over 2500 silicon compounds with physical properties, chemical structures and application data is provided. 608 pages + inserts. Review Chapters: An Organosilicon Chemistry Primer; Naming Silicon Compound; Polysilanes; Silicon-Based Anion Relay Chemistry; Bioactive Organosilanes;Cross-Couling of Silanols and Silanolates; Silicon-Based Blocking Agents; Silanes and Surfaces; Bond Dissociation Energies of Organosilicon Compounds; Si NMR: Practical Aspects; Infrared Analysis of Organosilicon Compounds; Ring-Opening Polymerization of Cyclosiloxanes; Telechelic Siloxane Oligomers; Silicones: Stable, Inert Media; Reactive Silicones and Elastomer Formulation. Detailed and referenced properties for ~2500 Silicon Compounds are presented. 608 pages
Direct formation of chlorodimethylsilane from silicon and chloroform
The Journal of Physical Chemistry, 1989
A Cu-catalyzed reaction procedure was found for the selective formation of dimethylchlorosilane [(CH3)2HSiCl] from the direct reaction of CH3C1 with solid Si. The new procedure is a two-step process. A Cu/Si sample is prepared by evaporating Cu onto clean polycrystalline Si under ultrahigh vacuum, and the Cu/Si surface is first activated by exposure to 10% HSiCl3/CH3Cl at 598 K. After the HSiCl3/CH3Cl mixture is evacuated from the reactor, the activated Cu/Si surface is reacted in fresh CH3C1. For low surface concentrations of Cu, the partially hydrogenated silane, (CH3)2HSiCl, is selectively produced. Trichlorosilane was also found to activate polycrystalline Si (in the absence of Cu) for production of highly chlorinated methylchlorosilanes at a much higher rate than on the Cu/Si surface but with poor selectivity to (CH3)2HSiCl. All reactions are carried out at atmospheric pressure in a reactor that is attached to an ultrahigh-vacuum chamber. This allows surface analysis by Auger electron spectroscopy, which detected SiCl* on reacted surfaces. These SiCl* sites, which appear necessary for methylchlorosilane formation, are apparently formed during activation by HSiCl3. Reactions on the Si and Cu/Si surfaces were studied in an atmospheric pressure, differential reactor, which was attached to an ultrahigh-vacuum system that contained an Auger spectrometer. Auger electron spectroscopy (AES) provides elemental surface composition and some chemical bonding information for Si because the Si(LVV) Auger transition is sensitive to the valence state of Si. All reactions were carried out at 598 K because this corresponds to the highest temperature used in previous studies on Cu3Si bulk alloys8 and it is in the upper temperature range t Department of Chemical Engineering.
The reaction of tris(trimethylsilyl)silane with acid chlorides
Tetrahedron Letters, 1992
Tris(trimethylsilyl)silane, in contrast with tributyltin hydride, reduces acid chlorides to the corresponding decarboxylated hydrocarbons via a free radical mechanism. This methodology could be a viable alternative to Barton's decarboxylation reaction.