Theoretical investigation on the reactions of H with (CH3)4-nSiHn (n = 1-4)

The abstractions of H with (CH3)(4-n) SiHn (n = 1-4) have been investigated at high levels of ab initio molecule orbital theory. Geometries have been optimized at the MP-2 level with 6-31G(d) basis set, and G2MP2 level has been used for the final energy calculations. Theoretical analysis provided conclusive evidence that the main process occurring in each case is the abstraction of H from the Si-H bond leading to the formation of the H-2 and silyl radicals; the abstraction of H from C-H bond has higher barrier and is difficult to read in each case. The kinetics of the title reactions have been calculated with variational transition-state theory over the temperature range 200-1000 K, and the theoretical rate constants match well with the experimental values.