A combined CASSCF and TDDFT study on the structures and properties of formyl cyanide in low-lying electronic states

Abstract

The low-lying electronic states (S 0, S 1, S 2, S 3, T 1, T 2, T 3) of formyl cyanide have been studied by the CASSCF, B3LYP, and MP2 calculations with cc-pVDZ or aug-cc-pVDZ basis set. The structural features and properties of these states have been characterized on the basis of structural optimizations and molecular orbital calculations. The relatively high barriers to the CH and CC bond fissions on the S 1 and T 1 pathways reveal that the S 1 or T 1 dissociation of formyl cyanide proceeds with little probability upon photoexcitation to the S 1 state.