Cationic and alkynyl complexes of the trans(mesityl)bis(phenyldimethylphosphine)nickel(II) moiety

Abstract

A cationic complex, trans-[(mesityl)Ni(PPhMe 2) 2(NCMe)]ClO 4 (IIa), has been prepared rom trans-(mesityl)Ni(PPhMe 2) 2Br and silver perchlorate in acetone/acetonitrile. IIa reacts with several neutral ligands to give trans-[(mesityl)Ni(PPhMe 2) 2L]ClO 4 (L = 2-pic, 3-pic, 3,4-lut, 2,5-lut, methyl isonicotinate, N-ethyl imidazole, PPhMe 2, P(Ome) 3), with halide anions to give trans-(mesityl)Ni(PPhMe 2) 2X (X = Cl, NNN), and with terminal alkynes in the presence of triethylamine to give trans-(mesityl)Ni(PPhMe 2) 2CCR (R = H, Me, CH 2CH 2Oh, Ph, C 6H 4OMe- p). Some related alkynyl complexes trans-CCl 2CClNi(PPhMe 2) 2CCR (R = H, Me, Ph, C 6H 4OMe- p) and trans-{( o-MeO) 2C 6H 3}Ni(PPhMe 2) 2CCr (R = H, Ph) also have been prepared from the corresponding trans-R′Ni(PPhMe 2) 2Cl, silver perchlorate and HCCR in acetonitrile-triethylamine. trans-(Mesityl)Ni(PPhMe 2) 2CCH reacts with methanol in the presence of perchloric acid to give a cationic carbne complex, trans-[(mesityl)Ni(PPhMe 2) 2{C(OMe)Me}]ClO 4.