ELECTROCHEMICAL SYNTHESIS OF GROUP-10 METAL-COMPLEXES OF ISOCYANIDE CONTAINING METAL-METAL BONDS

Electrochemical preparations of the Group 10 metal isocyanide complexes containing metal-metal bonds are described. Electrochemical reductions of [MCl2(RNC)2] and [M(RNC)2(L2)]2+ (M=Pd, Pt; L2=2RNC, 2 PPh3, Ph2P(CH2)nPPh2=diphos) were carried out at Pt and Hg electrodes and gave di- tri-, and high nuclear complexes, [M2Cl2(RNC)4], [M2(RNC)4L2]2+, [M3(RNC)6L2]2+, [HgPt6(RNC)12], [HgPt6(RNC)8(diphos)2], [Hg2Pt6(RNC)8(diphos)2], and [Hg2Pt6(RNC)6(diphos)3], depending on the charge consumed and reduction potential. Electrochemistry of NiX2(RNC)2 8 at a Pt electrode is quasi-reversible, but the reaction at a Hg electrode proceeded with the CE mechanism ; an initial chemical reaction of 8 with a Hg electrode occurred to give [{HgNi(RNC)4X2}2], and finally the redox reaction of the Hg complex was observed. Reactions of dimeric complexes with isocyanide, ML2 (M=Ni, Pt), or ML3 (M=Pd) fragments were carried out and the corresponding A-frame or linear trimetallic complexes were obtained.