Ab initio study of the electronic spectrum of 7-hydroxyquinoline

Abstract

The electronic spectrum of 7-hydroxyquinoline has been studied by using ab initio Multi-State Multi-Reference M??ller-Plesset Second-Order Perturbation Theory (MSMRMP2). The energy range up to 6.5 eV is taken into consideration. The lowest ??-??* transition is calculated to have an energy of 3.65 eV in good agreement with experimental data. Several other ??-??* transitions are predicted to have excitation energies of 4.93, 5.20, 5.47, and 6.08 eV. Excitations out of the highest occupied ?? orbital into the lowest unoccupied ??* orbitals are computed to occur at 5.28 and 6.44 eV. The ??-??* transition is predicted at 5.87 eV. The ??* orbital involved is identified as the Rydberg 3s orbital having antibonding character along the OH bond.close1