Synthesis and characterization of ruthenium and osmium complexes of heterocyclic bidentate ligands (N, X), X = S, Se

Abstract

The reaction of [RuCl 2(PPh 3) 3] and [OsBr 2(PPh 3) 3] precursors with a series of heterocyclic bidentate (N, X) ligands, X = S, Se, gave complexes [M(R-pyS) 2(PPh 3) 2], (R = H, 3-CF 3, 5-CF 3, 3-Me 3Si); [M(R-pymS) 2(PPh 3) 2], (R = 4-CF 3, 4,6-MeCF 3) and [M(R-pySe) 2(PPh 3) 2], (R = H, 3-CF 3, 5-CF 3), where M is Ru or Os, pyS and pymS the anions of pyridine-2-thione and pyrimidine-2-thione, respectively, and pySe is the anion produced by the reductive cleavage of the Se–Se bond in the dipyridyl-2,2′-diselenide. All of the compounds obtained were characterized by microanalysis, IR, FAB, NMR spectroscopy and by cyclic voltammetry. Compounds [Ru(3-CF 3-pyS) 2(PPh 3) 2] · 2(CH 2Cl 2) ( 2), [Ru(3-Me 3Si-pyS) 2(PPh 3) 2] ( 4), [Ru(4-CF 3-pymS) 2(PPh 3) 2] ( 5), [Ru(3-CF 3-pySe) 2(PPh 3) 2] · 2(CH 2Cl 2) ( 8), [Os(3-CF 3-pyS) 2(PPh 3) 2] · (CHCl 3) ( 11), [Os(3-Me 3Si-pyS) 2(PPh 3) 2] ( 13), [Os(3-CF 3-pySe) 2(PPh 3) 2] · 2(CH 2Cl 2) ( 17), [Os(5-CF 3-pySe) 2(PPh 3) 2] · 2(H 2O) ( 18) and [OsCl 2(4,6-MeCF 3-pymS)(PPh 3) 2] ( 19) were also characterized by X-ray diffraction. In all cases, the metal is in a distorted octahedral environment with the heterocyclic ligand acting as a bidentate (N, S) chelate system.