title: Preparation of tetrabutylammonium salt of a mono-Ru(III)-substituted α-Keggin-type silicotungstate with a 4,4'-bipyridine ligand and its electrochemical behaviour in organic solvents.
abstract: The tetrabutylammonium (TBA) salt of a mono-ruthenium(III)-substituted α-Keggin-type silicotungstate with a 4,4'-bipyridine (bipy) ligand, TBA5[α-SiW11O39Ru(III)(bipy)] (1), which is soluble in various organic solvents, was prepared by a cation exchange reaction of Cs5[α-SiW11O39Ru(III)(bipy)] with tetrabutylammonium bromide. Compound 1 was characterised using IR, (1)H-NMR, elemental analysis, single crystal X-ray analysis, X-ray absorption near-edge structure (XANES) analysis (Ru L3-edge), electron spin resonance (ESR), cyclic voltammetry (CV) and UV-Vis. Single crystal X-ray analysis of 1 revealed that the Ru(III) unit was incorporated into the α-Keggin-type silicotungstate framework and coordinated by a bipy molecule through a Ru-N bond. CV indicated that the incorporated Ru(III)-bipy was reversibly oxidised to the Ru(IV)-bipy derivative and reduced to the Ru(II)-bipy derivative in organic solvents. The redox potential of Ru(IV/III)-bipy was found to be affected by organic solvents. Moreover, the Ru(V)-bipy derivative was observed in acetonitrile.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, 739-8527, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Ogo
authors.forename: Sachie
authors.initials: S
authors.lastname: Moroi
authors.forename: Tadaharu
authors.initials: T
authors.lastname: Ueda
authors.forename: Kenji
authors.initials: K
authors.lastname: Komaguchi
authors.forename: Shinjiro
authors.initials: S
authors.lastname: Hayakawa
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ide
authors.forename: Tsuneji
authors.initials: T
authors.lastname: Sano
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sadakane