Structure characterization and antitumor activity of palladium pseudo halide complexes with 4-acetylpyridine

Abstract

The addition of an aqueous solution of palladium chloride to an aqueous acetonitrile solution of 4-acetylpyridine (4-Acpy) and KSCN or NaN₃ produces new complexes, [Pd(SCN)₂(4-Acpy)₂] (1) and [Pd(N₃)₂(4-Acpy)₂] (2), at ambient conditions. Complexes 1 and 2 were characterized by elemental analysis, FT-IR, and UV-Visible spectra. The structures of 1 and 2 were determined by single crystal X-ray diffraction. The coordination geometry around the palladium center is distorted square planar in 1 and 2 as the palladium is coordinated with two 4-acetylpyridine and two thiocyanates in 1 or two azide groups in 2. The discrete units of 1 and 2 extend along the a-axis creating a 1 D-chain via non-covalent hydrogen bonds. The extensive non-covalent hydrogen bonds extend the structure of 1 and 2 to 3D-networks. Using MTT assay, the cytotoxic activities of 1 and 2 were screened against two cancer cell lines, HePG-2 (liver cancer) and MCF-7 (breast cancer). The MTT assay revealed that the cytotoxic activity of 1 is stronger than 2 for HePG-2 and MCF-7. Antioxidant and anti‐hemolytic activities of 1 and 2 were examined. Furthermore, the luminescence spectra in the solid state of 1 and 2 are discussed.

Keywords:

• In vitro cytotoxicity
• palladium complexes
• pseudo halide
• 4-acetylpyridine
• non-covalent hydrogen bonds
• luminescence

Disclosure statement

No potential conflict of interest was reported by the authors.