Quantum Chemical Investigation of Structures,Energies of ClPS and ClSP and of Their Photo Rearrangement

The geometries of S₀, T₁ amd S₁ states of ClPS, ClSP and those of the transition states for the photo-unimolecular rearrangement from ClPS to ClSP are optimized by gradient technique, based on RHF or UHF ab initio methods with STO-3G^* basis set. The optimized geometries of the ground state ClPS and the theoretically calculated first three ionization energies are in good agreement with the experimental data. With correlation correction by means of MP₄/6-31G^* method, from the potential energy profiles, we wxpect that the isomer ClSP may be obserable through photo-rearrangement of ClPS.