201231-94-9Relevant academic research and scientific papers
Preparation and electrochemical reactions of nickel(II) complexes containing isocyanide and mono- or di-phosphines
Yamamoto, Yasuhiro,Takahata, Hiroyuki,Takei, Fumie
, p. 369 - 379 (2007/10/03)
Reactions of cis-NiCl2(diphos) (diphos = PPh2(CH2)nPPh2: n = 2 (dppe); n = 3 (dppp)) with isocyanide in the presence of NH4PF6 gave [NiCl(diphos)(XylNC)2](PF6) (1, 2) or [Ni(diphos)(RNC)3](PF6)2 (3, 4) (R = 2,6-Me2C6H3 (Xyl), 2,4,6-Me3C6H2 (Mes)). Similar reactions of NiCl2(PPh3)2 with xylyl isocyanide gave [NiCl(PPh3)2(XylNC)2](PF6) 5 and [Ni(PPh3)2(XylNC)3](PF6)2 6. The structures of these five-coordinated complexes were confirmed to be square-pyramidal by X-ray analyses: [NiCl(dppp)(XylNC)2](PF6) · CH2Cl2 2a, a = 13.345(2) A, b = 10.984(2) A, c = 33.082(4) A, β = 97.13(1)°, V = 4812(3) A3, monoclinic, P21/c, z = 4, R = 0.064; [Ni(dppe)(MesNC)3](PF6)2 3b, α = 12.763(3) A, b = 13.110(3) A, c = 17.114(3) A, β = 102.55(2)°, V = 2795(2) A3, monoclinic, Pn, z = 2, R = 0.051; [NiCl(PPh3)2(XylNC)2](PF6) 5a, a = 13.768(5) A, b = 17.23(1) A, c = 11.063(6) A, α = 98.86(4)°, β = 95.97(4)°, γ = 75.48(3)°, V = 2504(2) A3, triclinic, P1, z = 2, R = 0.O63. The CV's of these complexes showed to be quasi-reversible with two-electron transfer. The potentials of complexes (1, 2, 5) shifted to more negative region than those of the corresponding 3, 4, and 6, respectively. There exists an equilibrium between 1 and 3 in the presence of isocyanide on the basis of the E1/2 potentials, but no equilibrium between 2 and 4. Complex 5 was completely converted to 6 in the presence of xylyl isocyanide. These complexes were not influenced for excess diphosphine.
