Knowledge Bank

Resonance Raman excitation profiles, absorption spectra and fluorescence spectra are calculated for a hypothetical molecule modelled after an electron donor/acceptor complex. The effects on the calculations of the shapes of the potential energy surfaces and of the different inter-nuclear distances in the two electronic states are discussed. Both the excitation profile and the fluorescence spectrum are predicted to be red shifted with respect to the absorption spectrum, consistent with the experimental results for the charge transfer transitions in complexes with tetracyanoethylene as electron acceptor and aromatic electron donors.