80006-27-5Relevant academic research and scientific papers
Reactions of alkyl isocyanides with polyhydride complexes of rhenium and with binuclear dirhenium complexes containing quadruple or triple bonds: Nonreductive and reductive cleavage of Re-Re multiple bonds to afford mononuclear isocyanide complexes of rhenium(I) and rhenium(III)
Allison, Joe D.,Wood, Thomas E.,Wild, Robert E.,Walton, Richard A.
, p. 3540 - 3546 (2008/10/08)
Treatment of the dinuclear quadruply bonded complexes Re2(O2CR)4Cl2 (R = CH3 or C6H5) with alkyl isocyanides (RNC; R = CMe3 or C6H11) affords solutions from which salts of the [Re(CNR)6]+ cations can be isolated in good yield. While [Re(CNR)6]+ is inert to substitution by monodentate tertiary phosphines, routes to species of the type [Re(CNR)4(PR3)2]+ are afforded by (a) the reductive cleavage of the triply bonded complexes Re2Cl4(PR3)4 by RNC ligands or (b) the reductive elimination of H2 from the polyhydride complexes ReH7(PR3)2 and ReH5(PR3)2L in the presence of an excess of RNC. In contrast to the preceding reductive-cleavage reductions, the halide-rich salts (n-Bu4N)2Re2X8 (X = Cl or Br) react with tert-butyl isocyanide to give mononuclear seven-coordinate rhenium(III) species [Re(CNCMe3)5X2]+, which have been isolated as their PF6- salts. The mixed isocyanide-halide-phosphine complexes of rhenium(III) [Re(CNCMe3)4(PEtPh2)Cl2]PF 6 and [Re(CNCMe3)3(dppe)Cl2]PF6 (dppe = Ph2PCH2CH2PPh2) are likewise prepared by isocyanide cleavage of quadruply bonded Re2Cl6(PEtPh2)2 and dimeric Re2Cl6(dppe)2 (the latter containing Re(μ-Cl)2Re bridges but no Re-Re bond). The spectroscopic and electrochemical properties of these complexes are reported, and the significance of the cleavage reactions by π-acceptor ligands (such as RNC) is discussed in the context of their constituting an important synthetic route to mononuclear transition-metal complexes.
REDOX REACTIONS OF POLYHYDRIDE COMPLEXES OF RHENIUM: ELECTROCHEMISTRY AND REACTIONS WITH ALKYL ISOCYANIDES
Allison, J. D.,Cameron, C.J.,Wild, R.E.,Walton, R.A.
, p. C62 - C66 (2007/10/02)
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.
