Pyridine-2-selenolate and -2-tellurolate as ligands: a multinuclear (77Se, 119Sn, 125Te) magnetic resonance study of some tin(IV) complexes, and X-ray structural analyses of Sn(SPh)2(2-Se-C5H4N-N,Se)2 and Sn(SPh)1.85(2-Se-C5H4N)2.151

Article abstract of DOI:10.1139/v96-238

Reactions between Sn(E′Ph)_n and the bis(pyridine) dichalcogenides 2,2′-(C₅H₄NE)₂ have been studied using multinuclear (⁷⁷Se, ¹¹⁹Sn, ¹²⁵Te) magnetric resonance. In this way the occurrence of the pyridine-2-chalcogenate complexes Sn(E′Ph)_4-x(Epy)_x has been demonstrated. The pattern of ¹¹⁹Sn NMR chemical shifts for Sn(E′Ph)_4-x(Sepy)_x is consistent with bidentate bonding for the pySe^- ligand when x = 1 and 2. The pyTe^- ligand is probably bidentate also in all four complexes containing this ligand. As part of the NMR analysis, ⁷⁷Se and (or) ¹²⁵Te NMR data were obtained for py₂Te₂ and for the new mixed dichalcogenides PhE′ER, which were produced in the systems Ph₂E′₂:R₂E₄. The complex Sn(SPh)₂(Sepy)₂ (1) was isolated pure and its structure determined by the single crystal X-diffraction technique. The structure confirms that the PySe^- ligand behaves in a chelating manner. The molecule Sn(SPh)₂(2-Se-C₅H₄N-N,Se)₂ has a distorted octahedral structure with the PhS^- ligands in cis positions and the two Se donor atoms in trans positions. En route to 1, the yellow crystalline compound Sn(SPh)_1.85(2-Se-C₅H₄N)_2.15 (2) was isolated. This was shown by ¹¹⁹Sn NMR spectroscopy to contain both Sn(2-Se-C₅H₄N)₂ and Sn(2-Se-C₅H₄N)₃(SPh). The crystal and molecular structure of 2 was determined by single crystal X-ray diffraction techniques.