Synthesis and solid-state structural characterisation of Pt(II,IV) bromide complexes containing bidentate organothiomethylpyridine heteroleptic ligands

A convenient synthetic method for the preparation of organothiomethylpyridine ligands 2-(RSCH2)C5H4N (R = Ph (L1), Me (L2)), 2-MeS–6-Me-C5H3N (L3), and 2-MeS–4-Me-C5H3N (L4) via the initial lithiation of substituted 2-picolines followed by the nucleophilic reaction with a diorganyldisulfide is described. The complexes [PtBr2L] (L = L1–L4) have been prepared in good to high yields as yellow solids with low solubility in organic solvents. The solid state structures of the complexes have been determined, showing the spatial arrangement of the complexes to depend significantly upon varying substituents within the ligand. The complexes undergo oxidation by bromine to form the tetravalent complexes [PtBr4(L)] (L = L1–L4). The solid state structures of [PtBr4(L2)] and [PtBr4(L4)] have been determined, and shown to be monomeric with the ligand chelating the platinum centre.

Graphical abstractPyridyl thioether ligands are readily formed by lithiation of 2-picolines followed by reaction with diorgano disulfides, and the synthesis and structural studies of platinum(II) and platinum(IV) complexes are described.Figure optionsDownload full-size imageDownload as PowerPoint slide