Solvent effect on the photo-induced proton transfer in 2-(N-methyl-α-iminoethyl)-phenol

Effects caused by water environment on the photo-induced proton transfer in 2-(N-methyl-α-iminoethyl)-phenol molecule are investigated by means of quantum chemical calculations. After the electronic excitation, the protonated Schiff base is twisted out from the molecular plane and later reverts to the initial state. Two possible energy relaxation pathways are revealed: photon emission from the excited-state minimum, and the non-radiative conversion through the conical intersection. Accounting for the local solvent interactions introduces substantial changes of the ground- and excited-state potential energy surfaces. These changes offer an explanation for the observed formation of the intermediate photoproducts of aromatic anils in polar solvents.