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)3Cl2] with 2-(benzylimino-methyl)-4-R-phenol (HRL, R = H, Cl, Br and OMe) in boiling methanol in presence of triethylamine afford ruthenium(II) complexes of general formula [Ru(RL)(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 RL− 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).