Synthesis, characterization, and cytotoxicity of Pt (II) and Pd (II) complexes with 2-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline as ligand

Pt(II) and Pd(II) complexes have emerged as highly potent anticancer drugs, and their efficacy in treating of various types cancer has garnered increasing attention. Herein, we report two trapezoid planar structures of promising complexes with 2-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline as a ligand. The structures of complexes 1 and 2 were studied by a series of characterizations, including single-crystal X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. Fluorescence and UV-vis spectra, revealed the hypochromic phenomenon, which demonstrates the capacity of the complexes 1 and 2 interacting with ct-DNA. Furthermore, the ability of the complexes 1 and 2 to cut DNA was validated by the agar gel electrophoresis experiment. The cytotoxicity of 1 was assessed using flow cytometry analysis and morphology analysis. It is worth noting that, complex 1, had obvious advantages in inducing HeLa cell apoptosis, and the number of apoptotic cells (49.5 %) is significantly higher than that in the control group (1.6 %), after 24 h. Moreover, 1 can generate singlet oxygen and hydroxyl radical to damage cells under light irradiation, thus achieving an excellent to induced HeLa cells apoptosis. Overall, this work illustrated that complexes 1 and 2 are promising candidates for inducing apoptosis in HeLa cells.