title: Synthesis and properties of the cyano complex of oxo-centered triruthenium core [Ru3(μ3-O)(μ-CH3COO)6(pyridine)2(CN)].
abstract: The preparation and properties of a new cyano complex containing the Ru3(μ3-O) core, [Ru3(μ3-O)(μ-CH3COO)6(py)2(CN)] (1; py = pyridine), are reported. Complex 1 in CH2Cl2 showed intense absorption bands at 244, 334, and 662 nm, corresponding to a π-π* transition of the ligand, cluster-to-ligand charge transfer, and intracluster transitions, respectively. The cyclic voltammogram of 1 in 0.1 M (n-Bu)4NPF6-CH2Cl2 showed redox waves for the processes Ru3(II,II,III)/Ru3(II,III,III), Ru3(II,III,III)/Ru3(III,III,III), and Ru3(III,III,III)/Ru3(III,III,IV) at E1/2 = -1.49, -0.26, and +1.03 V vs Ag/AgCl, respectively. The first two redox potentials are more negative by ca. 0.2 V in comparison with the corresponding potentials of [Ru3(μ3-O)(μ-CH3COO)6(py)3](+). This is in sharp contrast to the positive shifts of the corresponding waves of [Ru3(II,III,III)(μ3-O)(μ-CH3COO)6(py)2(CO)]. Density functional theory (DFT) calculations of [Ru3(II,III,III)(μ3-O)(μ-CH3COO)6(py)3], [Ru3(II,III,III)(μ3-O)(μ-CH3COO)6(py)2(CN)](-), and [Ru3(II,III,III)(μ3-O)(μ-CH3COO)6(py)2(CO)] showed that the positive charge of the ruthenium is delocalized over the triruthenium cores of the first two and is localized as Ru(II)(CO){Ru(III)(py)}2 in the CO complex. The calculations explain the difference in the π interactions of the two ligands with the triruthenium cores.
authors.affiliation: Catalysis Research Center, Hokkaido University , Sapporo 001-0021, Japan.
authors.forename: Hua-Xin
authors.initials: HX
authors.lastname: Zhang
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shen
authors.initials: S
authors.lastname: Ye
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Osawa
authors.forename: Masaaki
authors.initials: M
authors.lastname: Abe
authors.forename: Kohei
authors.initials: K
authors.lastname: Uosaki
mesh_terms: D002248:Carbon Monoxide / Q000737:chemistry; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D055664:Electrochemical Techniques; D008958:Models, Molecular; D009570:Nitriles / Q000138:chemical synthesis / Q000737:chemistry*; D010084:Oxidation-Reduction; D011725:Pyridines / Q000138:chemical synthesis / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D009570:Nitriles; D011725:Pyridines; D002248:Carbon Monoxide; D012428:Ruthenium; C023666:pyridine