Structural and antiproliferative properties of Pd(II) triazolate complex formed by catalyst-free [3 + 2] click reaction

To address the adverse effects of cisplatin, which include nausea, neurotoxicity, nephrotoxicity, and ototoxicity, analogues can be made by replacing the labile chlorido and/or inert ammine ligands, or even by using other d⁸ metal ions like Au(III) or Pd(II). The antiproliferative properties of triazolato Pd(II) complex of 2-quinoline-carboxyaldehyde-N⁴-phenylthiosemicarbazone, which is formed under catalyst-free conditions, from the reaction of the corresponding azide complex with 4,4,4-trifluoro-2-butynoic acid ethyl ester, was screened against four cancerous and one normal cell lines of different origins. A variety of analytical and spectrscopic methods was used to characterize the complex's structure fully, and density functional theory computations were used to supplement the investigation. Biologically, the MTT assay revealed moderate cytotoxicity of the triazolate complex against the tested maligant and normal cell lines. The complex enhanced ROS production and arrested the cell cycle in the S- and the G₂/M phases.