title: Chemical reactivity and electrochemistry of metal-metal-bonded zincocenes.
abstract: Attempts to prepare mixed-ligand zinc-zinc-bonded compounds that contain bulky C(5)Me(5) and terphenyl groups, [Zn(2)(C(5)Me(5))(Ar')], lead to disproportionation. The resulting half-sandwich Zn(II) complexes [(η(5)-C(5)Me(5))ZnAr'] (Ar' = 2,6-(2,6-(i)Pr(2)C(6)H(3))(2)-C(6)H(3), 2; 2,6-(2,6-Me(2)C(6)H(3))(2)-C(6)H(3), 3) can also be obtained from the reaction of [Zn(C(5)Me(5))(2)] with the corresponding LiAr'. In the presence of pyr-py (4-pyrrolidinopyridine) or DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), [Zn(2)(η(5)-C(5)Me(5))(2)] reacts with C(5)Me(5)OH to afford the tetrametallic complexes [Zn(2)(η(5)-C(5)Me(5))L(μ-OC(5)Me(5))](2) (L = pyr-py, 6; DBU, 8), respectively. The bulkier terphenyloxide Ar(Mes)O(-) group (Ar(Mes) = 2,6-(2,4,6-Me(3)C(6)H(2))(2)-C(6)H(3)) gives instead the dimetallic compound [Zn(2)(η(5)-C(5)Me(5))(OAr(Mes))(pyr-py)(2)], 7, that features a terminal Zn-OAr(Mes) bond. DFT calculations on models of 6-8 and also on the Zn-Zn-bonded complexes [Zn(2)(η(5)-C(5)H(5))(OC(5)H(5))(py)(2)] and [(η(5)-C(5)H(5))ZnZn(py)(3)](+) have been performed and reveal the nonsymmetric nature of the Zn-Zn bond with lower charge and higher participation of the s orbital of the zinc atom coordinated to the cyclopentadienyl ligand with respect to the metal within the pseudo-ZnL(3) fragment. Cyclic voltammetric studies on [Zn(2)(η(5)-C(5)Me(5))(2)] have been also carried out and the results compared with the behavior of [Zn(C(5)Me(5))(2)] and related magnesium and calcium metallocenes.
authors.affiliation: Instituto de Investigaciones Químicas-Departamento de Química Inorgánica, Universidad de Sevilla-Consejo Superior de Investigaciones Científicas, Avenida Américo Vespucio 49, 41092 Sevilla, Spain.
authors.forename: Mario
authors.initials: M
authors.lastname: Carrasco
authors.forename: Riccardo
authors.initials: R
authors.lastname: Peloso
authors.forename: Irene
authors.initials: I
authors.lastname: Resa
authors.forename: Amor
authors.initials: A
authors.lastname: Rodríguez
authors.forename: Luis
authors.initials: L
authors.lastname: Sánchez
authors.forename: Eleuterio
authors.initials: E
authors.lastname: Álvarez
authors.forename: Celia
authors.initials: C
authors.lastname: Maya
authors.forename: Rafael
authors.initials: R
authors.lastname: Andreu
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Calvente
authors.forename: Agustín
authors.initials: A
authors.lastname: Galindo
authors.forename: Ernesto
authors.initials: E
authors.lastname: Carmona