10097-28-6Relevant articles and documents
Investigation of the Prototype Silylene Reaction, SiH2 + H 2O (and D2O): Time-Resolved Gas-Phase Kinetic Studies, Isotope Effects, RRKM Calculations, and Quantum Chemical Calculations of the Reaction Energy Surface
Becerra, Rosa,Cannady, J.Pat,Walsh, Robin
, p. 11049 - 11056 (2003)
Time-resolved kinetic studies of the reaction of silylene, SiH 2, with H2O and with D2O have been carried out in the gas phase at 296 and at 339 K, using laser flash photolysis to generate and monitor SiH2. The reaction was studied over the pressure range 10-200 Torr with SF6 as bath gas. The second-order rate constants obtained were pressure dependent, indicating that the reaction is a third-body assisted association process. Rate constants at 339 K were about half those at 296 K. Isotope effects, kH/kD. were small averaging 1.076 ± 0.080, suggesting no involvement of H- (or D-) atom transfer in the rate determining step. RRKM modeling was undertaken based on a transition state appropriate to formation of the expected zwitterionic donor-acceptor complex, H2Si ... OH2. Because the reaction is close to the low pressure (third order) region, it is difficult to be definitive about the activated complex structure. Various structures were tried, both with and without the incorporation of rotational modes, leading to values for the high-pressure limiting (i.e., true second-order) rate constant in the range 9.5 × 10-11 to 5 × 10-10 cm3 molecule-1 s-1. The RRKM modeling and mechanistic interpretation is supported by ab initio quantum calculations carried out at the G2 and G3 levels. The results are compared and contrasted with the previous studies.
Infrared spectra and density functional calculations of the SiCO4 molecule in solid argon
Dong, Jian,Miao, Lei,Zhou, Mingfei
, p. 31 - 36 (2002)
The SiCO4 molecule has been produced by reaction between silicon dioxide and carbon dioxide molecules in solid argon. Silicon dioxide molecules were prepared by reactions of laser-ablated silicon atoms with oxygen in excess argon. When carbon d
Woodward, R.,Hayden, J. S.,Gole, J. L.
, p. 153 - 170 (1985)
Kinetics of the SiH3 + O2 reaction: A new transition state for SiO production
Murakami,Koshi,Matsui,Kamiya,Umeyama
, p. 17501 - 17506 (1996)
The mechanism of SiO formation in the laser photolysis of SiH4/O2/CCl4 mixtures was investigated using a laser-induced fluorescence method. Measured rates for the SiO production corresponded to the decay rates of SiH3 radical and depended linearly on the O2 concentration. The yield of SiO was estimated on the basis of LIF intensity, and it was found that SiO was one of the major products in the SiH3 + O2 reaction. The bimolecular rate constant for the SiO production was determined to be (1.14 ± 0.18) × 10-11 cm3 molecules-1 s-1. Ab initio molecular orbital calculations were performed for various pathways of the SiH3 + O2 reaction. Geometries were optimized at the MP2(full)/6-31G(d) level of theory, and relative energies and barrier heights were calculated at the G2(MP2) level of theory. Silyl radical and O2 react to form SiH3OO, which irreversibly decomposes to various excited products. A new transition state for the production of cyclic H2SiO2 (siladioxirane) + H from SiH3OO adduct was found. Possible decomposition channels of the vibrationally excited products of the SiH3 + O2 reaction to produce SiO are discussed.
Raman-spectroscopy of oligomeric SiO species isolated in solid methane
Friesen, Markus,Junker, Markus,Zumbusch, Andreas,Schnoeckel, Hansgeorg
, p. 7881 - 7887 (2007/10/03)
From the IR-spectra of matrix isolated SiO species a D2h-structure has been postulated for the dimer and a D3h-structure for the trimer. High quality Raman-spectra - necessary for the complete characterization - were missing so far. Here we report the Raman-spectra especially of the totally symmetric vibrations for Si2O2 and Si3O3 and their 16O/18O isotopomers isolated in solid methane. We also detect the most intense A1-vibration of Si4O4 and can assign it with its 16O/18O isotopic splitting. Ab initio calculations for all oligomers are presented in order to support the assignment of the spectra and to obtain geometric and energetic information about the oligomeric species which have been detected experimentally.
