title: Time-dependent density functional theory investigation of electric field effects on absorption spectra of meso-meso-linked zinc porphyrin arrays: Role of charge-transfer States.
abstract: By using time-dependent density functional theory, we calculated the transition energies of a zinc porphyrin monomer and its meso-meso-linked arrays. In line with the prediction of the molecular exciton model, the calculated splitting energy of the Soret band increased as the number of linked porphyrins increased. We then examined how the transition energies of the dimer array were shifted by an applied electric field. For reproduction of an electroabsorption spectrum (EA), i.e., the field-induced change in absorption intensity, a model Hamiltonian constructed from five states is proposed. It is concluded for the dimer that the field-induced coupling between the lower-energy Soret band Se and the lower-lying ionic character (charge-transfer) states is responsible for the experimentally observed blue shift of Se as well as the second-derivative profile in the EA spectrum.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Nakai
authors.forename: Riadh
authors.initials: R
authors.lastname: Sahnoun
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kato
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Kono
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Fujimura