Non-radiative deactivation channels of molecular rotors

Abstract

On the basis of the fluorescence properties of a series of intramolecular charge-transfer complexes of varied structure ( p-( N, N-dialkylamino) benzylidene malononitriles and coumarin laser dyes) in an inert solvent (ethyl acetate), a model of non-radiative decay is proposed. The model specifically describes the relative contributions of the possible internal relaxation channels to non-radiative energy dissipation of the S 1, ct states via the free rotor mechanism. The results are consistent with the theoretical predictions based on the calculated electron density distributions and the bond-order alternation in the S 1, ct state.