Abstract
Solvent spectral frequency shifts have been used to investigate the structural and molecular properties of P-benzoquinone (PQ), anthraquinone (AQ) and 2, 3-dichloro-5,6-dicyano-pbenzoquinone (DDPQ). The spectral behaviours, in terms of transition energies and intensities, electric dipole moment and polarizabilities in excited states, are interpreted in terms of symmetries and molecular structures of these compounds.