The electrochemistry and spectroelectrochemistry of a novel series of mixed-ligand diruthenium compounds were examined. The investigated compounds having the formula Ru-2(CH3CO2)(x)(FaP)(4-x)Cl where x = 1 -3 and Fap is 2-(2-fluoroanilino)pyridinate anion were made from the reaction of Ru-2(CH3CO2)(4)Cl with 2-(2-fluoroanilino)pyridine (HFap) in refluxing methanol. The previously characterized Ru-2(FaP)(4)Cl as well as the three newly isolated compounds represented as Ru-2(CH3CO2)(FaP)(3)Cl (1), Ru-2(CH3CO2)(2)(FaP)(2)Cl (2), and Ru-2(CH3CO2)(3)(Fap)Cl (3) possess three unpaired electrons with a Ru-2(5+) dimetal core. Complexes 1 and 2 have well-defined Ru2+/(4+) and Ru-2(5+)/6(+) redox couples in CH2Cl2, but 3 exhibits a more complicated electrochemical behavior due to equilibria involving association or dissociation of the anionic chloride axial ligand on the initial and oxidized or reduced forms of the compound, The E-1/2 values for the Ru-2(5+)/(4+) and Ru-2(5+)/(6+) processes vary linearly with the number of CH3CO2- bridging ligands on Ru-2(CH3CO2)(x)FaP)(4-x)Cl and plots of reversible half-wave potentials vs the number of acetate groups follow linear free energy relationships with the largest substituent effect being observed for the oxidation. The major UV-visible band of the examined compounds in their neutral Ru-2(5+) form is located between 550 and 800 nm in CH2Cl2 and also varies linearly with the number of CH3CO2- ligands on Ru-2(CH3CO2) Fap)(4-x)Cl. The electronic spectra of the singly oxidized and singly reduced forms of each diruthenium species were characterized by UV-visible spectroelectrochemistry in CH2Cl2.