The π-Electronic Excitation Energies of Anthraquinone

Following our previous work on o-benzoquinone, the calculation of the π-electronic excitation energies of anthraquinone has been carried out with the Pariser-Parr-Pople method. The calculated excitation energies which correspond to the five distinct π→π* bands have been obtained, though the agreement of the calculated excitation energies and the transition dipole-strengths with the observed energies and strengths are unsatisfactory. The π-electronic charge distribution in carbonyl groups of anthraquinone is almost the same as that of p-benzoquinone.