Solvent-dependent resonance Raman excitation profiles of 9,9′-bianthryl

Dynamics subsequent to the electronic excitation of 9,9′-bianthryl produce a polar emissive excited state for which the symmetry of the bichromophore is broken by a dynamic solvent stabilisation of one of the two, otherwise degenerate, charge transfer configurations which contribute to the excited electronic state. The initial state created upon excitation is examined here by analysis of ground state resonance Raman excitation profiles (REPs) and electronic absorption spectra in solvents of various polarities. The results suggest that the REPs are signalling electronic differences between the initially excited state in the various solvents. We suggest that this is related to the bianthryl excited state being responsive to the disordered solvent environment.