Reactions of Schiff Base‐Substituted Diselenides and ‐tellurides with Ni(II), Pd(II) and Pt(II) Phosphine Complexes

The salicylidene Schiff bases of bis(2‐aminophenyl)diselenide and ‐ditelluride react with [M II Cl 2 (PPh 3 ) 2 ] (M = Ni, Pt) or [Pd II (OAc) 2 (PPh 3 ) 2 ] with formation of square‐planar complexes with the general formulae [M II (L Y )(PPh 3 )] (M = Ni, Pd, Pt, Y = Se, Te). The ligands coordinate to the metals as tridentate {O,N,Se/Te} chelates. The reduction of the dichalcogenides and the formation of the chalcogenolato ligands occurs in situ by released PPh 3 ligands. A mechanism for such reactions has been derived from the experimental data with the aid of DFT calculations. It suggests a higher polarization of the dichalcogenide bond with partial charge separation upon coordination to a metal centre, which therefore facilitates the cleavage of the dichalcogenide bond with PPh 3 . In accordance with the proposed mechanism, best yields are obtained with a strict exclusion of oxygen, but in the presence of water.