A new binuclear mixed-valence complex [ReCl 4 (py)(μ-O)Re(py) 4 Cl]·2py was obtained by solvothermal synthesis in a Berghoff autoclave. It has been studied by IR, reflectance spectra, TGA and X-ray measurements, which support the assumption, that two Re centres with different coordination environments are present. Most plausible, yet not unambiguous oxidation state assignment is Re III/IV . A new binuclear mixed-valence complex [ReCl4(py)(μ-O)Re(py)4Cl]·2py with Re centres of different coordination environments was obtained by solvothermal syntheses.