Synthesis, Crystal Structures and Anticancer Activity of Pt(II) Complexes with Two Sterically Hindered 2-Methylpyridine Groups as The Carrier

Abstract

A series of novel platinum(II) complexes with two sterically hindered 2-methylpyridine groups as the carrier, cis-[Pt(2-methylpyridine)₂X₂] (X = Cl– (1), oxalate (2), malonate (3), 1,1-cyclobutane dicarboxylate (4), 3-hydroxy-1,1-cyclobutane dicarboxylate (5), were synthesized and characterized by elemental analysis, IR, mass spectra and ¹H NMR spectra. The crystal structures of complexes 3-5 were further determined by X-ray single crystal diffraction. The two pyridine moieties adopts an almost perpendicular orientation relation to the platinum coordination plane and the two CH₃ groups are located above the coordination plane, approaching Z axis. These structural arrangements produce greater steric hindrance for ligand substitution reactions. Unfortunately the complexes do not show any significant anticancer activity against A549, A549/ATCC and SGC-7901 cancer cell lines, possibly due to the fact that they lack hydrogen atoms on N-donors.