Ruthenium(II) complexes with 2-(benzylimino-methyl)-4-R-phenol containing the trans(PPh3),cis(CO,Cl)-{Ru(PPh3)2(CO)Cl}+ unit

Reactions of [Ru(PPh3)(3)Cl-2] with 2-(benzylimino-methyl)-4-R-phenol ((HL)-L-R, R = H, Cl, Br and OMe) in boiling methanol in presence of triethylamine afford ruthenium(II) complexes of general formula [Ru(L-R)(PPh3)(2)(CO)Cl] in 57-64% yield. Microanalysis, spectroscopic (infrared, electronic and NMR) and cyclic voltammetric measurements have been used for the characterization of the complexes. Crystal structures of two representative complexes have been determined by X-ray crystallography. The carbonyl, the chloride, the N,O-donor L-R and the two mutually trans PPh3 molecules assemble a distorted octahedral CClNOP2 coordination sphere around the metal centre in each complex. The complexes display the Ru(II) -> Ru(III) oxidation in the potential range 0.62-1.16 V (vs. Ag/AgCl). (C) 2009 Elsevier B.V. All rights reserved.