title: Tetrakis(thiadiazole)porphyrazines. 6. Spectroelectrochemical and density functional theory studies of the anions [TTDPzM](n-) (n = 1-4; M = Zn(II), Mg(II)(H(2)O), Cu(II), 2H(I)).
abstract: Following previous cyclic voltammetric studies of tetrakis(thiadiazole)porphyrazines [TTDPzM] where M = Zn(II), Mg(II)(H(2)O), Cu(II), or 2H(I) in nonaqueous media, a thin-layer spectroelectrochemical investigation was carried out in pyridine to characterize each stepwise one-electron reduction of the electrogenerated [TTDPzM](n-) complexes where n = 1-4. A similar UV-visible spectrum was observed for each form of the anion, independent of the central metal ion and detailed theoretical calculations by density functional theory (DFT) and time-dependent DFT (TDDFT) methods were applied to interpret the spectral features of [TTDPzZn](n-) (n = 1-4) which was selected as representative for describing the ground and excited-state electronic structures of the entire [TTDPzM](n-) series. The use of two exchange-correlation functionals, the pure, asymptotically correct statistical average of orbital potentials (SAOP) and the hybrid B3LYP functionals, proved to be essential for attaining a correct assignment of the key spectral features. The nature and intensity of the main spectral features are highlighted and interpreted on the basis of the ground-state electronic structure of the complexes.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Roma La Sapienza, P.le A. Moro 5, Roma, I-00185, Italy.
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Donzello
authors.forename: Claudio
authors.initials: C
authors.lastname: Ercolani
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Cai
authors.forename: Karl M
authors.initials: KM
authors.lastname: Kadish
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Ricciardi
authors.forename: Angela
authors.initials: A
authors.lastname: Rosa