Electrochemistry of platinum(II) coordination compounds II. Electroreduction of trimetallic dimetalliobis(isocyanide)platinum(II) complexes

Linear trimetallic MPPt^IIL₂M complexes (M = Cr(CO)₃(η-C₅H₅), Mo(CO)₃- (η-C₅H₅), W(CO)3(η-C₅-H₅), Mn(CO)₅, Fe(CO)₃NO, Co(CO)₄; L = t-BuNC, cyclo- C₀H₁₁ NC) are reduced on platinum and gold electrodes in non-aqueous medium. All these complexes undergo irreversible one electron reductions, which result in the rupture of one Ptmetal bond and the liberation of one M^? ion per mole reduced. Coupled ESR spectroscopy and coulometry show that a radical is generated during the reduction of the trimetallic complexes. The several ESR signals obtained for these paramagnetic Pt¹ species exhibit no hyperfine structure.The electrochemical behaviour of MPtL₂M complexes is compared with that of the following linear trimetallic complexes: MHgM and (MAuM)^?.