Synthesis, characterisation, electrochemistry and reactivity of osmium-palladium carbonyl complexes containing 1,1'-bis(diphenylphosphino)ferrocene (dppf); molecular structures of [Os5PdC(CO)(14)(mu-dppf)], [OsPd(mu-I)(2)I-2(CO)(2)(mu-dppf)](2) and [{Os5C(CO)(14)}(2)(mu-dppf)]

The hexanuclear osmium-palladium carbonyl carbide cluster [Os5PdC(CO)(14)(mu-dppf)] 1 [dppf = 1,1'-bis(diphenylphosphino)ferrocene] has been synthesized in 56% yield by the reaction of [N(PPh3)(2)](2)[Os5C(CO)(14)] with [Pd(dppf)(H2O)(2)][O3CCF3](2). When treated with iodine in CH2Cl2 at ambient conditions, compound 1 underwent cluster degradation to give the macrocyclic complex [OsPd(mu-I)(2)I-2(CO)(2)(mu-dppf)](2) 2. Thermolysis of complex 1 in refluxing chloroform gave the dppf bridged dimeric cluster [{Os5C(CO)(14)}(2)(mu-dppf)] 3. The structures of 1-3 were characterised by IR, H-1, P-31 NMR and mass spectroscopies and X-ray crystallography. Electrochemical investigations revealed that complex]. underwent a reversible one-electron oxidation at the ferrocene centre followed by a quasi-reversible oxidation of the metal cluster core.