Palladium(II) Complexes Based on N,S-Donor Ligands: Synthesis and Molecular Structures

Abstract

Phenyl(chloro)dithioformate is treated with pyrazole derivatives and phenyl(Pz-1-carbodithioate) ligands (Pz = pyrazole (1), 3-methylpyrazole (2), and 3,5-dimethylpyrazole (3)) are obtained. These ligands are treated with PdCl₂ in acetonitrile and complexes of the general formula Pd(L)Cl₂ form in an essentially quantitative yield. The ligands are found to be N,S-bidentate linkers, and 5-membered palladacycles are obtained. Precursors 1–3 are oily materials and characterized by ¹H and ¹³C NMR spectroscopy. Due to a partial solubility of Pd complexes, the complete set of NMR data cannot be collected. The structural elucidation is also accompanied by elemental and mass spectrometric analyses. Solid-state structures of complexes 5 and 6 are determined by X-ray diffraction. The data obtained for complexes 5 and 6 are also calculated by DFT using the TURBOMOLE program package. Experimental and calculated data sets are found to be in close agreement with each other.