CuAAC “Click”-Derived Luminescent 2‑(2-(4-(4-(Pyridin-2-yl)‑1H‑1,2,3-triazol-1-yl)butoxy)phenyl)benzo[d]thiazole-Based Ru(II)/Ir(III)/Re(I) Complexes as Anticancer Agents

To enhance the cytoselective behavior of the complexes, we intended to develop a CuAAC “click”-derived synthetic protocol for the preparation of 2-(2-(4-(4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)­butoxy)­phenyl)­benzo­[d]­thiazole-based Ru­(II)/Ir­(III)/Re­(I) complexes, and their cytotoxicity against three different cancer cell lines (MCF-7, HeLa, and U87MG) in consort with one normal cell line (HEK-293) was evaluated. In our detailed investigations, the significant cytotoxic nature of the Ru­(II) complex 7a compared to Ir­(III) and Re­(I) complexes (7b and 7c, respectively) was observed. Complex 7a was capable of MCF-7 cell apoptosis via the inhibition of both S- and G2/M-phase cell cycle arrest in association with a substantial quantity of ROS production and DNA intercalation.