title: Theoretical analysis of singlet and triplet excited states of nickel porphyrins.
abstract: Local density and generalized gradient approximation time-dependent density functional methods have been used for calculation of the singlet and triplet excited states of nickel-porphine, Ni-tetraphenyloporphine, and Ni-octaethyloporphyrine. Special attention is paid to metal-ligand transitions and d-d transitions. It is shown that the lowest exited singlet states of the three compounds can be described as a transfer of an electron from the porphine ring to the d(x2-y2) orbital of the nickel atom. On the other hand, the lowest excited triplet state arises from promotion of an electron between two nickel d orbitals, an occupied d(z2) and an empty d(x2-y2). It is proposed that a rapid quenching of the excited singlet states is due to an ultrafast intersystem crossing between 1Eg)and 3Eg or 3B1g states.
authors.affiliation: Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa K1A 0R6, Canada.
authors.forename: Serguei
authors.initials: S
authors.lastname: Patchkovskii
authors.forename: Pawel M
authors.initials: PM
authors.lastname: Kozlowski
authors.forename: Marek Z
authors.initials: MZ
authors.lastname: Zgierski