Xb. Ou et Af. Janzen, SILICON-FLUORINE AND SILICON-CARBON BOND-CLEAVAGE IN ORGANOFLUOROSILICATES - A MOLECULAR-ORBITAL STUDY, Inorganic chemistry, 36(3), 1997, pp. 392-395
The mechanism of silicon-fluorine and silicon-carbon bond cleavage in
organofluorosilanes and -silicates is analyzed with the aid of molecul
ar orbital calculations. The optimized geometries of reactants and int
ermediates are calculated, and these calculations support the view tha
t cleavage of Si-F bonds occurs by way of fluorine-bridged Si-F-Si int
ermediates. Cleavage of a Si-C bond in PhSiF(3) takes place in the pre
sence of fluoride ion and oxidizing agents, and the calculations are i
n agreement with the formation of PhSiF(4)(-) and PhSiF(5)(2-), follow
ed by oxidation to a radical anion PhSiF(5)(-) The latter species, how
ever, is predicted to decompose rapidly to give anionic SiF5-, and phe
nyl radicals. These calculations and the proposed mechanisms of bond c
leavage are in agreement with experimental data, where available.