title: On the road to MM'X polymers: redox properties of heterometallic Ni···Pt paddlewheel complexes.
abstract: On the quest of heterometallic mixed-valence MM'X chains, we have prepared two stable discrete bimetallic compounds: the reduced (PPN)[ClNi(μ-OSCPh)4Pt] (PPN = bis(triphenylphosphine)iminium; OSCPh = benzothiocarboxylato) and the oxidized [(H2O)Ni(μ-OSCPh)4PtCl] species. The role of the aqua and chlorido axial ligands is crucial to facilitate oxidation of the {Ni(μ-OSCPh)4Pt} core. Experimental and theoretical analyses indicate that a NiPt-Cl/Cl-NiPt isomerization process occurs in the oxidized species. The electronic structure of the reduced system shows two unpaired electrons, one located in a d(x(2)-y(2)) orbital of the Ni(II) ion and a second in the antibonding d(z(2)-dz(2)) combination from the Ni(II) and Pt(II) centers. Oxidation occurs by removing one electron from this second multicenter molecular orbital. Although the mixed-valence character of the oxidized species makes the isolation of MM'X chains very attractive, such polymeric structure is prevented by the low Pt-Cl···Ni interaction energy and the high tendency of Ni centers to coordinate water molecules. Thus, this work offers valuable insights and hints to engage the production of heterometallic mixed-valence MM'X chains, which still is a challenging task.
authors.affiliation: Departamento de Química Inorgánica, Universidad Autónoma de Madrid , 28049 Madrid, Spain.
authors.forename: Marcello
authors.initials: M
authors.lastname: Gennari
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Givaja
authors.forename: Oscar
authors.initials: O
authors.lastname: Castillo
authors.forename: Laura
authors.initials: L
authors.lastname: Hermosilla
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Gómez-García
authors.forename: Carole
authors.initials: C
authors.lastname: Duboc
authors.forename: Agustí
authors.initials: A
authors.lastname: Lledós
authors.forename: Ruben
authors.initials: R
authors.lastname: Mas-Ballesté
authors.forename: Felix
authors.initials: F
authors.lastname: Zamora