13931-97-0Relevant academic research and scientific papers
Unusual isotope effect in the reaction of chlorosilylene with trimethylsilane-1-d. Absolute rate studies and quantum chemical and Rice-Ramsperger-Kassel-Marcus calculations provide strong evidence for the involvement of an intermediate complex
Becerra, Rosa,Boganov, Sergey E.,Egorov, Mikhail P.,Krylova, Irina V.,Promyslov, Vladimir M.,Walsh, Robin
experimental part, p. 10493 - 10501 (2012/08/08)
Time-resolved studies of chlorosilylene, ClSiH, generated by the 193 nm laser flash photolysis of 1-chloro-1-silacyclopent-3-ene, have been carried out to obtain rate constants for its bimolecular reaction with trimethylsilane-1-d, Me3SiD, in the gas phase. The reaction was studied at total pressures up to 100 Torr (with and without added SF6) over the temperature range of 295-407 K. The rate constants were found to be pressure independent and gave the following Arrhenius equation: log[(k/(cm3 molecule -1 s-1)] = (-13.22 ± 0.15) + [(13.20 ± 1.00) kJ mol-1]/(RT ln 10). When compared with previously published kinetic data for the reaction of ClSiH with Me3SiH, kinetic isotope effects, kD/kH, in the range from 7.4 (297 K) to 6.4 (407 K) were obtained. These far exceed values of 0.4-0.5 estimated for a single-step insertion process. Quantum chemical calculations (G3MP2B3 level) confirm not only the involvement of an intermediate complex, but also the existence of a low-energy internal isomerization pathway which can scramble the D and H atom labels. By means of Rice-Ramsperger-Kassel-Marcus modeling and a necessary (but small) refinement of the energy surface, we have shown that this mechanism can reproduce closely the experimental isotope effects. These findings provide the first experimental evidence for the isomerization pathway and thereby offer the most concrete evidence to date for the existence of intermediate complexes in the insertion reactions of silylenes.
Direct detection of chlorosilylene and time resolved study of some of its reactions in the gas-phase using a new photochemical precursor
Becerra,Boganov,Egorov,Krylova,Nefedov,Walsh
, p. 194 - 200 (2007/10/03)
Chlorosilylene, ClSiH, was prepared by 193 nm laser flash photolysis of 1-chloro-1-silacyclopent-3-ene in the gas phase. ClSiH was monitored in real time at 457.9 nm using a CW argon ion laser. The kinetics of reactions of ClSiH with C2H4, CH2CHCMe3, C 2H2, Me2O, SO2, HCl, MeSiH 3, Me2SiH2, Me3SiH, MeGeH 3, Me2GeH2 and precursor have been studied at ambient temperatures for the first time. Addition reactions of ClSiH and reactions with lone pair donors are faster than insertion reactions. Surprisingly ClSiH inserts faster into Si-H than Ge-H bonds. ClSiH is intermediate in reactivity between SiH2 and SiCl2. Relative reactivities of ClSiH and SiH2 vary considerably.
Time-resolved gas-phase kinetic and quantum chemical studies of reactions of silylene with chlorine-containing species. 1. HCl
Becerra, Rosa,Cannady, J. Pat,Walsh, Robin
, p. 3987 - 3993 (2007/10/03)
Time-resolved kinetic studies of the reaction of silylene, SiH2, generated by laser flash photolysis of phenylsilane, have been carried out to obtain rate constants for its bimolecular reaction with HCl. The reaction was studied in the gas phas
