Solvent effects on intramolecular charge separation

Solvent polarity effects on the energetics of charge separation processes, in particular on proton transfer in 1-morpholinomethyl-2-naphthol (M2N), were studied and discussed in the frame of a continuum model. The obtained results were compared to electron transfer (TICT) inp-cyano-N,N-dimethylaniline (CDMA). Solvatochromic shifts of M2N were explained by an increase of the molecular dipole moment on excitation, but more importantly by a rotation of its direction. A minimum in the excited state lifetime in an intermediate polarity region was attributed to a maximum radiationless transition probability.