Oxorhenium mixed-ligand complexes with the 2,6-dimercaptomethylpyridine ligand. Crystal structure of [2,6-dimercaptomethylpyridinato][p-methoxybenzenethiolato]oxorhenium(V)

Two novel oxorhenium complexes containing the 2,6-dimercaptomethylpyridine ligand were synthesized and characterized by classical methods of analysis. The [2,6-dimercaptomethylpyridinato][p-methoxybenzenethiolato]oxorhenium complex 1, was produced by simultaneous action of equimolar quantities of 2,6-dimercaptomethylpyridine and p-methoxybenzenethiol on the precursor [(n-C4H9)4N][ReOCl4] in EtOH. As revealed by spectroscopic data as well as X-ray structure analysis, complex 1 adopts a distorted square pyramidal geometry around the metal with the SNS/S donors forming the basal plane and the oxygen occupying the apex of the pyramid. When the same tridentate ligand reacts with [(n-C4H9)4N][ReOCl3(PO)] (PO=o-diphenylphosphinophenolato) as a precursor, complex 2a, [2,6-dimercaptomethylpyridinato][o-diphenylphosphinophenolato]-oxorhenium, is obtained. The latter is a six-coordinate rhenium species to which the distorted octahedral geometry is assigned, according to the analytical findings. In this case, the SNS/P donors occupy the equatorial plane and the two oxygen atoms the apices of the distorted octahedron positioned trans to each other.