Synthesis of a Family of Pd(II) Complexes Using Pyridyl-Ketone Ligands: Crystal Structure, Thermal, Physicochemical, XRD/HSA, Docking, and Heck Reaction Application.

Abstract

Four Pd(II) complexes, (dpk)PdCl2 (complex-1), and (dpk)Pd(OAc)2 (complex-2) have been prepared using di(2-pyridyl) ketone as the chelate ligand (dpk). The (dpk·EtOH)PdCl2 (complex-3) and (dpk·EtOH)Pd(OAc)2 (complex-4) were synthesized by selectively introducing complex-1 and complex-2 to an EtOH in situ nucleophilic addition reaction on the O=C of the dpk ligand, respectively. All complexes were characterized using CHN-EA, UV-vis, FT-IR, FAB-MS, EDX, TGA, and NMR physicochemical tools. The XRD-crystallography technique was employed to ascertain the structure of complex-3. The analysis revealed a monoclinic/P21/c crystal system characterized by a square planar structure oriented in the cis direction around the Pd center. Several C-H···Cl and O-H···O H-bonds constructing 2D-S12 and S7 synthons were confirmed via XRD/HSA interactions. The influence of EtOH addition to the O=C group of dpk in (dpk)PdCl2 was documented by using UV-vis/FT-IR spectra and TGA analysis. As catalysts, all complexes have demonstrated a notable catalytic function in the Heck reaction, resulting in a high yield under gentle conditions using iodobenzene and methyl acrylate as model reactions. Moreover, the complex-1 and complex-3 docking activity was evaluated against 1BNA-DNA.