Secondary Coordination Sphere Effects in Ruthenium(III) Tetraammine Complexes: Role of the Coordinated Water Molecule

Author(s)

Souza, Maykon L. ^[1] ; Castellano, Eduardo E. ^[2] ; Telser, Joshua ^[3] ; Franco, Douglas W. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim, Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Inst Fis, Sao Carlos, SP - Brazil

^[3] Roosevelt Univ, Dept Biol Chem & Phys Sci, Chicago, IL 60605 - USA

• Document type: Journal article
• Source: Inorganic Chemistry; v. 54, n. 4, p. 2067-2080, FEB 16 2015.
• Web of Science Citations: 7

Abstract

Stabilization of TaTa bonding in an oxide across a shared octahedral-site edge of a Ta-2 dimer is not known. Investigation of Li insertion into the trirutile structure of MTa2O6 with M = Mg, Cr, Fe, Co, and Ni indicates that TaTa bonding across the shared octahedral-site edge of the dimer can be stabilized by a reversible electrochemical reduction of TaV to TaIV for M = Cr, Fe, Co, and Ni but not for M = Mg. Chemical reduction of MTa2O6 by n-butyl lithium only reduced NiTa2O6 to any significant extent. With M = Fe, Co, or Ni, electrochemical formation of the TaTa bonds is accompanied by a partial reduction of the FeII, CoII, or NiII to Fe0, Co-0, or Ni-0. For M = Cr, two Li per formula unit can be inserted reversibly with no displacement of Cr0. For M = Mg, no MgII are displaced by Li insertion, but a solidelectrolyte interphase (SEI) layer is formed on the oxide with no evidence of TaTa bonding. Stabilization of TaTa bonding across a shared octahedral-site edge in a dimer appears to require significant hybridization of the TaV 5d0 and M 4s0 states. (AU)

• FAPESP's process: 12/23651-4 - Nitrosyl and nitroxyl as ligands on Ru(II): synthesis, kinetics, reactivity and thermodynamics
• Grantee: Douglas Wagner Franco
• Support Opportunities: Regular Research Grants