Ab initio study on the rate constants of SiCl4 + H → SiCl3 + HCl
Abstract
The reaction SiCl4
+ H → SiCl3
+ HCl is studied using an ab initio dynamic method. The direct chlorine abstraction of reaction processes ia a C3v symmetry transition state is calculated by the intrinsic reaction coordinate (IRC) method at the UMP2/6-311G(d,p) level. The forward and reverse barriers are refined by UMP4(SDTQ) and UQCISD(T) single point energy calculations using the same basis set of 6-311G(d,p). The forward
barrier is calculated to be 24.34 kcal mol−1
at the UMP4(SDTQ) level and 22.62 kcal mol−1 at the UQCISD(T) level, while the reverse barrier is 22.46 and 21.90 kcal mol−1, respectively. The enthalpy of reaction
is calculated to be 1.94 kcal mol−1 at the UMP4(SDTQ) level and 0.72 kcal mol−1 at the UQCISD(T) level. The forward rate constants in the temperature range 1500–1800 K are calculated by the conventional and variational
transition state theory (