Theoretical quest for photoconversion molecules having opposite directions of the electric dipole moment in S and S1 states

Abstract

Ab initio calculations at the level of CASPT2 with Dunning's correlation consistent cc-pVXZ (X=D, T, Q) basis sets have been carried out for pyrimidine, quinoxaline, phthalazine, and their substituted compounds to find candidates that show a change in the direction of the electric dipole moment for the S(0)-->S(1) transition. The present calculations reveal that 6,7-difluorophthalazine and 6,7-dichlorophthalazine are strong candidates having a large and clear change in the direction of the electric dipole moment on the S(0)-->S(1) transition.