Synthesis and characterization of ruthenium complexes with 1-aryl-2-mercaptoimidazole ligands

Reactions of the vinyl ruthenium starting material Ru(CH=CHPh)Cl(CO)(PPh3)(2) (1) with 1-aryl-2-mercaptoimidazole (HLa, aryl = 4-chloro-phenyl; HLb, aryl = 4-methyl-phenyl; HLc, aryl = 4-nitro-phenyl) in the presence of sodium methoxide in dichloromethane and methanol afforded [Ru(CH=CHPh)(kappa(2)-L)(CO)(PPh3)(2)] (2a-2c). Treatment of 1 with HL in THF gave [RuCl(kappa(2)-L)(CO)(PPh3)(2)] (3a-3c) contaminant with formation of styrene as byproduct. Interactions of 1 with HLa in dichloromethane led to isolation of a novel dinuclear ruthenium complex [(CO)(PPh3)(CHNCH2Ph)Ru(mu-Cl)(2)(mu-S) RuCl(CO)(PPh3)] (4a) via N-H bond addition to styryl ligand. Complexes 2a-2c, 3a-3c, and 4a were characterized by microanalyses, IR, and (H-1, C-13, P-31) NMR spectroscopies. The molecular structures of 3a-3c and 4a have been determined by single-crystal X-ray diffraction. (C) 2012 Elsevier B. V. All rights reserved