Effects of Lewis Acids on the Thermal Rearrangements of Chloromethylsilane: A Density Functional Theory Study

• DOI: 10.1007/s12633-013-9162-2
• Publication Date: 2013-08-06T02:04:25Z
• Authors: Yiling Bei; Qingyang Liu; Shengyu Feng
• Keywords: Transition state; Transition state theory; Reaction coordinate

Understanding the thermal rearrangement mechanism of chloromethylsilane in the presence of Lewis acids is particularly important in industrial applications. In this study, the thermal rearrangements of chloromethylsilane under the catalysis of AlCl3 and BF3 were studied on the basis of density functional theory (DFT) at the B3LYP/6-311G (d, p) level. The structures of the reactants, transition states and products were located and fully optimized. The geometries of various stationary points and the harmonic vibrational frequencies were calculated at the same levels. The reaction paths were investigated and confirmed by intrinsic reaction coordinate (IRC) calculations. The results showed that the thermal rearrangement of chloromethylsilane in the presence of a Lewis acid occurred via two pathways (MX3-1 and MX3-2). Only pathway MX3-1 had a catalytic effect. The determining factor of the reaction activation energies and rates was the formation of the transition state in each reaction. Among all the reactions, the Al atom could form an approximate tetrahedral coordination with four Cl atoms, resulting in the lowest energy barrier. The kinetic and thermodynamic calculations also proved this result.