A new Pd(II) complex containing acetophenone oxime and 1,3-Bis(diphenylphosphino)propane ligands; crystal structure, catalytic activity, molecular docking and in vitro cytotoxic evaluation

Abstract

A new palladium (II) complex of the type [Pd{C,N-C6H4{C(Me) = NOH}-2}(dppp)]ClO4 (2) has been prepared by the reaction of the cyclopalladated oxime complex [Pd{C,N-C6H4{C(Me) = NOH}-2}(μ-Cl)]2 (1) with 1,3-Bis(diphenylphosphino)propane (dppp). The new complex has been synthesized via a bridge-splitting reaction in the presence of NaClO4 under mild conditions. Complex 2 was fully characterized by elemental analysis (CHN), spectroscopic methods (IR, 1H-, 31P-, 13C NMR) and single-crystal X-ray diffraction analysis. The structure shows the palladium atom to be in a slightly distorted square-planar geometry surrounded by one C,N-chelating oxime ligand and one P,P-chelating dppp ligand forming five- and a six-membered metallocyclic rings, respectively. The catalytic activity of complex 2 has been evaluated using Suzuki cross coupling reactions. The coupled products of these reactions were obtained in good to excellent yields and purity, low catalyst loading and short reaction times. The cytotoxic activity of complexes 1 and 2 were comparatively studied against HeLa, A549, and 1321 N1 cell lines, which showed a greater efficiency of the mononuclear complex 2 over the binuclear complex 1. Finally, molecular docking simulation was employed as a computational method to investigate the interactions of complexes 1 and 2 with the protein involved in apoptosis.