Theoretical study of the internal charge transfer in aminobenzonitriles

The theoretical study of P-aminobenzonitrile (ABD) and (p-dimethylamino)benzonitrile (DMABN) molecules at the CASPT2 and CASSCF level reveals the dual fluorescence process occurring in these systems. The molecules exhibit two fluorescence bands in the polar solvents. The fluorescence occurs primarily due to the small energy gap between the interacting states.