Complexes of late transition metals containing the mixed donor ligands 2,6-(RSCH2)2C5H3N (R = Ph, Me): Crystal structures of [{Cu(2,6-(PhSCH2)2C5H3N)(μ-X)}2] (X = Cl, Br) and [Ni(2,6-(PhSCH2)2C5H3N)Br2]

Abstract

A range of NiX₂ and CuX (X = halide) complexes containing the tridentate NS₂ ligands 2,6-bis(methylthiomethyl)pyridine (L¹) and 2,6-bis(phenylthiomethyl)pyridine (L²) were prepared. Reaction of CuX with 1 molar equivalent of L¹ or L² afforded the binuclear species [{CuL(μ-X)}₂] (L = L¹, X = Cl; L = L², X = Cl, Br, I). These compounds have been characterised by IR and ¹H NMR spectroscopies, mass spectrometry and microanalysis. Crystal structure determinations of [{CuL²(μ-X)}₂] (X = Cl, Br) confirm the dimeric nature of these complexes through bridging halide centres, with the NS₂ ligands coordinated through their pyridyl nitrogens and one of the sulfur atoms in a bidentate manner. Reaction of NiX₂ with 1 molar equivalent of L¹ or L² afforded mononuclear species for [NiLX₂] (L = L¹, X = I; L = L², X = Br, I) and binuclear species for [NiLX₂]₂ (L = L¹, X = Cl, Br; L = L², X = Cl). These compounds have limited solubility and were characterised through IR and UV-Vis reflectance spectroscopies and microanalysis. The crystal structure determination of [NiL²Br₂] confirms the compound to be monomeric with a five-coordinate, square pyramidal nickel centre.