Mixed valence properties of a pyrazine bridged ruthenium–iron complex

Abstract

A study is presented on the chemistry of the binuclear complex [(CN) 5 FepzRu(NH 3 ) 5 ] n (n = 0 for the II–III complex and n = −1 for the II–II complex, pz = pyrazine) in solid state and in aqueous solution. Evidence for a mixed valence transition for the II–III complex was observed in the near infrared region. Based on infrared and resonance Raman spectra, a trapped-valence or class II formulation was proposed for the complex. Cyclic voltammetry indicated the occurrence of two reversible waves at 0.48 V and 0.72 V vs. NHE, which were assigned to the oxidation of the ruthenium(II) and iron(II) centers, respectively.