Synthesis and comparative structural study of tris-chelated Sb(III), Bi(III) and Cr(III) diselenophosphinato complexes

The tris-chelated SbIII, BiIII, and CrIII complexes containing diselenophosphinate ligands, [(PhCH2CH2)2PSe2]− and [Ph2PSe2]−, have been synthesized and fully characterized by X-ray crystallography, solution NMR (31P, 77Se, and 1H), UV–Vis and ESI-mass techniques. X-ray diffraction analysis reveals that the M(Se2PR2)3 (M = Sb, Bi and Cr) complexes are isostructural. In each of the compounds, the metal center is chelated by the three diselenophosphinate ligands in a distorted octahedral configuration. The M(Se2P)3 fragment formed is similar to a three-bladed propeller. In BiIII and CrIII complexes, the R2PSe2− anions act as isobidentate ligands, whereas the anisobidentate nature of these anions in SbIII complexes is observed. In the crystal packing of the complexes [except for Cr(Se2PPh2)3], there are supramolecular Se⋯Se interactions between adjacent molecules, which lead to a loosely connected dimer.

Graphical abstractThe SbIII, BiIII, and CrIII diselenophosphinato complexes, M(Se2PR2)3 (R = Ph and CH2CH2Ph), have been synthesized and characterized by X-ray crystallography, solution NMR (31P, 77Se, and 1H), UV–Vis and ESI-mass techniques. These complexes reveal a “three-bladed propeller” type structure formed by central M(Se2P)3 framework.Figure optionsDownload full-size imageDownload as PowerPoint slide