Permanent and induced dipole moments in electronically excited aromatic molecules. The polarizability in excited states

The solvatochromic shifts of absorption and fluorescence spectra of trifluoromethyl derivatives of benzene and naphthalene show that the induced dipole moments in the first excited singlet state are very close to that of the ground state. The change in the polarizability of such molecules on electronic excitation is therefore very small, of the order of 10% from the ground-state polarizability.