Theoretical study and rate constants calculation for the reactions of SiH3 radical with SiH3CH3 and SiH2(CH3)2.

The multiple-channel reactions SiH3 + SiH3CH3 → products and SiH3 + SiH2(CH3)2 → products are investigated by direct dynamics method. The minimum energy path (MEP) is calculated at the MP2/6-31+G(d,p) level, and energetic information is further refined by the MC-QCISD method. The rate constants for individual reaction channels are calculated by the improved canonical variational transition state theory (ICVT) with small-curvature tunneling (SCT) correction over the temperature range of 200–2400 K. The theoretical three-parameter expression k1(T) = 2.39 × 10-23T4.01exp(-2768.72/T) and k2(T) = 9.67 × 10-27T4.92exp(-2165.15/T) (in unit of cm3 molecule-1 s-1) are given. Our calculations indicate that hydrogen abstraction channel from SiH group is the major channel because of the smaller barrier height among eight channels considered. © 2009 Wiley Periodicals, Inc. J Comput Chem 2010 [ABSTRACT FROM AUTHOR]