Measurement and SCF-CI PPP calculation of polarized absorption and magnetic circular dichroism of azuleno[5, 6, 7-cd]phenalene

Abstract

U.v.-visible polarized absorption spectra of azuleno[5, 6, 7-cd]phenalene have been determined from measurements of linear dichroism in stretched polymer sheets at 77 K. The magnetic circular dichroic (m.c.d.) spectrum has been measured in solution. π-Electron calculations of transition energies, oscillator strengths, polarization directions and m.c.d. B terms were performed and the results are in good agreement with the experimental data for several lower energy transitions. The energy level scheme and transition polarizations as well as signs of B terms can be understood easily on the basis of the HMO orbitals of azulene and m-divinylbenzene. At higher energies, numerous transitions overlap and a detailed analysis is impossible.