Thiabendazole-based Rh(III) and Ir(III) biscyclometallated complexes with mitochondria-targeted anticancer activity and metal-sensitive photodynamic activity.

Two pairs of Rh(III) and Ir(III) biscyclometallated complexes with thiabendazole (L), named [Ir-a]Cl and [Rh-a]Cl, and N-benzyl-thiabendazole (L), named [Ir-b]Cl and [Rh-b]Cl, have been designed and synthesized to explore the photophysical and biological effects that arise from changing both the metal center and the ancillary ligand. In the dark, the four metal complexes exhibit greater cytotoxicity than cisplatin against human colon (SW480) and human lung (A549) adenocarcinoma cell lines. Moreover, the pair of complexes bearing the ligand L is markedly more cytotoxic and present higher uptake values than complexes with L, thereby their biological properties were studied further to determine their mechanism of action.