Synthesis, spectroscopic characterization, and crystal structure of the bimetallic complex [Ni-2(mu-CO)(CO)(2)(mu-NH(PPh2)(2))(2)]

The dinuclear Ni(0) complex [Ni-2(mu-CO)(CO)(2)(mu-dppa)(2)] (1; dppa = bis (diphenylphosphino)amine) was synthesized by two routes in good yield. Comp lex 1 has a triclinic crystal system and P (1) over bar space group, with a = 13.009(1) Angstrom, b = 13.063(2) Angstrom, c = 14.664(2) Angstrom, alph a = 79.96(1)degrees, beta = 79.96(1)degrees, gamma = 71.32(1)degrees, and Z = 2. The structure of this compound exhibits two mu-coordinated dppa ligan ds in a cis,cis arrangement. Nickel atoms are at a 2.5824(7) A distance. Th eoretical calculations predict a 0.39 bond order between metal atoms. The c yclic voltammograms show two quasi-reversible redox pairs, which correspond to the successive oxidation of the metal centers. The dinuclear complex de scribed absorbs carbon monoxide, yielding a mixture of nickel carbonyl comp ounds.