USING PLATINUM(II) AS A BUILDING BLOCK TO 2-ELECTRON REDOX SYSTEMS - CRYSTAL-STRUCTURE AND REDOX BEHAVIOR OF CIS-[PTII(3-FERROCENYLPYRIDINE)2CL2]

Reaction of 3-ferrocenylpyridine (3-FcPy) with [Pt(II)Cl4]2- gave the square complex cis-[Pt(II)(3-FcPy)2Cl2], which was structurally characterized by X-ray crystallography. The compound, C33H32Cl2Fe2N2OPt, containing a disordered acetone molecule, crystallizes in the triclinic P1BAR space group, with unit cell parameters a = 9.976 (9) angstrom, b = 10.53 (1) angstrom, c = 16.89 (1) angstrom, alpha = 106.5 (1)-degrees, beta = 97.8 (1)-degrees, gamma = 102.8 (1)-degrees, V = 1621 (6) angstrom 3, Z = 2, and d(calcd) = 1.742 g cm-3. The structure converged to an R factor of 3.5%. cis-[Pt(II)(3-FcPy)2Cl2], in acetone, DMSO, or MeCN solution, undergoes a two-electron oxidation process, according to two one-electron reversible steps, which involve the two appended ferrocenyl fragments, whose potentials are separated by only the statistical term (36 mV). It is demonstrated that the cis-[py2Pt(II)] core is a convenient bridging unit to build up novel bis(ferrocene) systems, in which the two relatively close Fc fragments display independent redox activity