The synthesis and characterization of three oxidized derivatives of bis(diphenylphosphino)pyridine and their Sn(IV) complexes

The synthesis and spectroscopic characterization of three chalcogenophosphoryl ligands derived from pyridine is reported. The synthesis was based on the oxidation of C5H3N(PPh2)(2) by elemental sulfur and selenium, and hydrogen peroxide. As a part of our study on the coordination chemistry of the ligands, three new Sn(IV) complex cations of the general formula {[Ph2P(E)-C5H3N-P(E)Ph-2]SnCl3}(+) (E = O, S, Se) were also synthesized. All compounds were characterized by P-31 NMR and X-ray crystallography. The organic ligands are tridentate, with both chalcogens and nitrogen involved in chelation. The cations show an approximate octahedral core geometry and are paired with either SnCl5- or SnCl5(OH2)(-) anions. (C) 2003 Elsevier Science Ltd. All rights reserved.