Spectroelectrochemical Characterization of the Two-Step Redox System (μ-pz)Os(CN)52n- (n = 4, 5, 6; pz = Pyrazine). Similarities and Differences in Relation to the Creutz-Taube System. Inorganic Chemistry, (37)2:311--316, 1998. [PUMA: charge cyano dinuclear dinuclear;electrochem dinuclear;osmium osmium oxidn prepn pyrazine spectra spectroelectrochem transfer]