Palladium(II) and Platinum(II) Complexes with Bisphosphanes, [S2C=C(CN)2]2– and [Se2C=C(CN)2]2– as Chelating Ligands

Abstract

AbstractThe palladium(II) and platin(II) 1, 1‐dicyanoethylene‐2, 2‐dithiolates [(L–L)M{S2C=C(CN)2}] (M = Pd: L–L = dppm, dppe, dcpe, dpmb; M = Pt: dppe, dcpe, dpmb) were prepared either from[(L–L)MCl2] and K2[S2C=C(CN)2] or from [(PPh3)2M{S2C=C(CN)2}] and the bisphosphane. Moreover, [(dppe)Pt{S2C=C(CN)2}]was obtained from [(1, 5‐C8H12)Pt{S2C=C(CN)2}] and dppeby ligand exchange. The 1, 1‐dicyanoethylene‐2, 2‐diselenolates[(dppe)M{Se2C=C(CN)2}] (M = Pd, Pt) were prepared from[(dppe)MCl2] and K2[Se2C=C(CN)2]. The oxidation potentials of the square‐planar palladium and platinum complexes were determined by cyclic voltammetry. The reaction of [(dcpe)Pd(S2C=O)] with TCNE led to a ligand fragment exchange and gave the 1, 1‐dicyanoethylene‐2, 2‐dithiolate [(dcpe)Pd{S2C=C(CN)2}] in good yield.