Synthesis and characterization of metal diselenophosphates: M[Se2P(OR)2]2 (M = Pd, Pt; R = Et, nPr, iPr)

The first Pd(II) and Pt(II) complexes incorporating diselenophosphate (dsep) ligands are presented. Treatment of M(II) (M = Pd, Pt) salts with two equivalents of the dsep ligand in CH2Cl2 yielded square-planar compounds of the type M[Se2P(OR)2]2 (M = Pd, Pt; R = Et, iPr, nPr) (1a–2c). These complexes were characterized by elemental analysis, multinuclear NMR spectroscopy and X-ray diffraction (1b and 2b). The dsep ligands coordinate to the metal in an approximately isobidentate fashion and form four-membered Se–P–Se–M chelate rings. Structural elucidations indicated that minute differences exist in the M–Se bond distances and these were observed from solution 31P NMR studies, which exhibited two sets of satellites arising from one-bond coupling to 77Se nuclei. A packing diagram showed a chain-like motif which was composed of square-planar M[Se2P(OR)2]2 units and occurred via non-covalent Se⋯Se secondary interactions.

Graphical abstractThe first square-planar Pd(II) and Pt(II) complexes incorporating diselenophosphate ligands have been reported. Structural elucidations indicate that minute differences exist in the M–Se bond distances and these were observed from solution 31P and 77Se NMR studies. A packing diagram showed a chain-like motif which was composed of square-planar M[Se2P(OR)2]2 units and occurred via non-covalent Se⋯Se secondary interactions.Figure optionsDownload full-size imageDownload as PowerPoint slide