Novel biologically active paddlewheel-like palladium thiocyanate complex catalyzed cyanation of alkyl bromide utilizing Q-tube system: A green perspective

Abstract

A novel paddlewheel-like complex of [Pd(SCN)2(3-Acpy)2], (1) was produced at ambient temperature by adding an aqueous solution of palladium chloride to an aqueous acetonitrile solution of 3-acetylpyridine (3-Acpy) and potassium thiocyanate. Elemental analysis, Fourier-transform infrared (FT-IR), ultraviolet–visible (UV–vis), and nuclear magnetic resonance (NMR) spectroscopic methods were used to characterize complex 1 comprehensively. Single crystal X-ray diffraction was used to analyze the crystal structure of complex 1. The palladium atom is bonded to two 3-Acpy ligands and two thiocyanates groups in trans mode giving square planer geometry in complex 1. The discrete units of paddlewheel-like complex 1 through hydrogen bonding extend to form a 3D supramolecular network structure. The synthesized and characterized new palladium complex 1 was utilized as a precatalyst for the cyanation of alkyl bromide using potassium ferrocyanide as a benign cyanide source reagent. The suggested catalytic test reaction under high-pressure conditions via a Q-tube system in green solvent cyclopentyl methyl ether introduced high yields and a short reaction time. Moreover, the cytotoxic activity of complex 1 was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against HePG-2 of liver cancer and MCF7 of breast cancer cell lines. According to the findings, complex 1 has significant strong activity against the cancer cell lines HePG-2 and MCF-7. Additionally, the luminescence spectra of complex 1 were investigated.