Photoinduced intramolecular electron transfer and electronic coupling interactions in π- expanded imidazole derivatives.

An intramolecular excited charge transfer (CT) analysis of imidazole derivatives has been made. The determined electronic transition dipole moments has been used to estimate the electronic coupling interactions between the excited charge transfer singlet state ((1)CT) and the ground state (S0) or the locally excited state ((1)LE). The properties of excited (1)CT state imidazole derivatives have been exploited by the significant contribution of the electronic coupling interactions. The excited state intramolecular proton transfer (ESIPT) analysis has also been discussed.