Synthesis and characterization of cyclometallated palladium(II) dithiolate complexes of the type [Pd(E∩C)(S∩S)]

Article abstract of DOI:10.1016/S0022-328X(97)00361-6

Cyclometallated palladium(II) dithiolate complexes of the type [Pd(E∩C)(S∩S)] (where E∩CH N,N′-dimethylbenzylamine, azobenzene, 4-MeOC₆H₄CH=NC₆H₄Me-4, 2-phenylpyridine or tris-o-tolylphosphine; S∩S = S₂CNEt₂ or S₂P(OR)₂, R = Et, Prⁿ, Prⁱ, Buⁿ or Bu^s) have been synthesized by the reaction of [Pd(E∩C)(μ-X)]₂ (X = Cl, OAc) with sodium or ammonium salts of dithio acids. These complexes were characterized by elemental analysis, IR, NMR (¹H and ³¹P) and mass spectral data. Treatment of [Pd(N∩ C){S₂P(OPrⁿ)₂}] [N∩C = NC₅H₄-C₆H₄ or N(Ph)=NC₆H₄] with anhydrous HCl in diethyl ether afforded [Pd(E∩C)(μ-Cl)]₂ and the free dithio acid. When reaction was carried out with triphenylphosphine, a dynamic equilibrium was established between [Pd(N∩ C){S₂P(OPrⁿ)₂}] and [Pd(PPh₃)(η¹-C-N){S₂P(OPrⁿ)₂}]. The crystal structure of [Pd{N(Me)₂CH₂C₆H₄}{S₂P(OPrⁿ)₂}] (3) has been determined by X-ray diffraction. The compound exhibits distorted square-planar geometry around palladium atom.