The binuclear complex [Pt2Me2(PPY)(2)(mu-dppf)], 1, in which ppy = deprotonated 2-phenylpyridyl and dppf = 1,1'-bis(diphenylphosphino)ferrocene, was synthesized by the reaction of [PtMe(SMe2)(ppy)] with 0.5 equiv of dppf at room temperature. In this reaction when 1 equiv of dppf was used, the dppf chelating complex 2, [PtMe(dppf)(ppy-kappa C-1)], was obtained. The reaction of Pt(II)-Pt(II) complex 1 with excess Mel gave the Pt(IV)-Pt(IV) complex [Pt2I2Me4(ppy)(2)(mu-dppf)], 3. When the reaction was performed with 1 equiv of Mel, a mixture containing unreacted complex 1, a mixed-valence Pt(II)-Pt(IV) complex [PtMe(ppy)(mu-dppf)PtIMe2(ppy)], 4, and complex 3 was obtained. In a comparative study, the reaction of [PtMe(SMe2)(PPY)1 with 1 equiv of monodentate phosphine PPh3 gave [PtMe(ppy)(PPh3)], A. Mel was reacted with A to give the platinum(IV) complex [PtMe2I(ppy)(PPh3)], C. All the complexes were fully characterized using multinuclear (H-1, P-31, C-13, and Pt-195) NMR spectroscopy, and complex 2 was further identified by single crystal X-ray structure determination. The reaction of binuclear Pt(II)-Pt(II) complex 1 with excess Mel was monitored by low temperature 31 P NMR spectroscopy and further by 1H NMR spectroscopy, and the kinetics of the reaction was studied by UV-vis spectroscopy. On the basis of the data, a mechanism has been suggested for the reaction which overall involved stepwise oxidative addition of Mel to the two Pt(II) centers. In this suggested mechanism, the reaction proceeded through a number of Pt(II)-Pt(IV) and Pt(IV)-Pt([V) intermediates. Although Mel in each step was trans oxidatively added to one of the Pt(II) centers, further trans to cis isomerizations of Me and I groups were also identified. A comparative kinetic study of the reaction of monomeric platinum(II) complex A with Mel was also performed. The rate of reaction of Mel with complex 1 was some 3.5 times faster than that with complex A, indicating that dppf in the complex 1, as compared with PPh3 in the complex A, has significantly enhanced the electron richness of the platinum centers.