Computational study toward understanding the photodissociation mechanism of sarin

摘要

The potential energy surface for sarin (C_4H_(10)FO _2P) dissociation into (CH_3)_2CHO+PO(F)(CH _3), CH_3+(CH_3)_2CHOPO(F), and F+(CH_3)_2CHOPO(CH_3) in the T_1 and S_1 states were investigated at the complete-active-space self-consistent field (CASSCF) with the 6-31G** and aug-cc-PVDZ basis sets. The different reaction pathways are characterized on the basis of the computed potential energy surface and surface crossing point, the time-dependent density functional theory (TD-DFT) was used to calculate the vertical energies based on the CAS(8,7)/6-31G** optimized excited structures, which may provide some new insights into the mechanism of the ultraviolet photo-degradation of sarin molecules.