Synthesis, structure and antiproliferative activity of organometallic iridium(III) complexes containing thiosemicarbazone ligands

A series of half-sandwich iridium complexes (1–4) with thiosemicarbazone ligands in two types of coordination modes were synthesized and characterized. The molecular structures of compounds 1, 2 and 3 were determined using single-crystal X-ray diffraction analysis. The nature of the complexes was studied using density functional theory calculations. The stability of the complexes was investigated using UV–visible absorption spectroscopy. The compounds were further evaluated for their in vitro antiproliferative activities against HeLa, HepG2, CNE-2, SGC-7901, KB and HEK-293 T cell lines. Compound 2 displays the highest antiproliferative activity among the other analogues and cisplatin.