CATIONIC AND ALKYNYL COMPLEXES OF THE TRANS-(MESITYL)BIS(PHENYLDIMETHYLPHOSPHINE)NICKEL(II) MOIETY

A cationic complex, trans-[(mesityl)Ni(PPhMe2)2(NCMe)]ClO4 (IIa), has been prepared rom trans-(mesityl)Ni(PPhMe2)2Br and silver perchlorate in acetone/acetonitrile. IIa reacts with several neutral ligands to give trans-[(mesityl)Ni(PPhMe2)2L]ClO4 (L = 2-pic, 3-pic, 3,4-lut, 2,5-lut, methyl isonicotinate, N-ethyl imidazole, PPhMe2, P(Ome)3), with halide anions to give trans-(mesityl)Ni(PPhMe2)2X (X = Cl, NNN), and with terminal alkynes in the presence of triethylamine to give trans-(mesityl)Ni(PPhMe2)2CCR (R = H, Me, CH2CH2Oh, Ph, C6H4OMe-p). Some related alkynyl complexes trans-CCl2CClNi(PPhMe2)2CCR (R = H, Me, Ph, C6H4OMe-p) and trans-{(o-MeO)2C6H3}Ni(PPhMe2)2CCr (R = H, Ph) also have been prepared from the corresponding trans-R′Ni(PPhMe2)2Cl, silver perchlorate and HCCR in acetonitrile-triethylamine. trans-(Mesityl)Ni(PPhMe2)2CCH reacts with methanol in the presence of perchloric acid to give a cationic carbne complex, trans-[(mesityl)Ni(PPhMe2)2{C(OMe)Me}]ClO4. © 1979.