Photodissociation dynamics of ethylsilane: A b i n i t i o and RRKM study

The photodissociation dynamics of ethylsilane have been investigated by ab initio molecular orbital methods. Reactants, transition state structures, and products were fully optimized at HF/3-21G and HF/6-31G* levels of theory; relative energies have been calculated at MP4SDQ/6-31G*; and zero point energies and vibrational frequencies at HF/3-21G. The calculated geometries, barrier heights, and vibrational frequencies for primary dissociation channels of ethylsilane were used to compute a unimolecular dissociation rate constant k(E) by RRKM theory. The barrier height of H2 elimination (three center) is predicted to be 66.6 kcal/mol and is in good agreement with recent experimental estimates. These findings are discussed in the light of previous and recent experimental results on ehtylsilane.