REDOX REACTIONS OF POLYHYDRIDE COMPLEXES OF RHENIUM: ELECTROCHEMISTRY AND REACTIONS WITH ALKYL ISOCYANIDES

Article abstract of DOI:10.1016/S0022-328X(00)81019-0

The dark red octahydride complex of dirhenium, Re2H8(PPh3)4, undergoes a reversible one-electron oxidation to the blue mono-cation ⁺ (E1/2 -0.24 V vs.SCE by cyclic voltammetry).The X-band ESR spectrum of a dichloromethane glass (-160 deg C) containing the monocation is in accord with the HOMO being a delocalized metal-based orbital.Treatmentof the heptahydrides ReH7(PR3)2 (PR3 = PPh3 or PEtPh2) with C6H11NC or Me3CNC in the presence of KPF6 leads to the elimination of hydrogen and the formation of PF6.Electrochemical oxidation of ReH5(PPh3)2L (L = PPh3, PEtPh2, pyridine, piperidine or cyclohexylamine) activates these molecules to attack by RNC to afford rhenium(I) species.