ARYL- AND ACETYLENE-NICKEL(I) COMPLEXES

Article abstract of DOI:10.1016/0022-328X(85)80294-1

Reduction of various pentafluorophenylnickel(II) complexes in the presence of phosphines gives unstable nickel(I) compounds but Ni(C6F5)CO)2(PPh3)2 is isolated in the presence of CO.Similar NiR(CO)2(PPh3)2 (R=C6F5, C6Cl5, 2,3,5,6-C6Cl4H) are obtained by reaction of the halogenonickel(I) complex with MgRBr or LiR.Reduction of NiX2L2 in the presence of acetylenes gives 2(μ-PhC<*>CR) (R=H, X=Cl and R=Ph, X=Cl, Br) when L=P-n-Bu3 but only NiX(PPh3)3 are recovered when L=PPh3.No reaction with the alkyne is observed for n but n reacts with RC<*>CR' to give paramagnetic NiCl(PPh3)(CR<*>CR') (R=Ph, R'=H, COOEt), diamagnetic 2(μ-PhC<*>CPh) and cyclotrimerization when R=R'=COOMe.Chemical and structural behaviour of the new nickel(I) complexes is described.