Synthesis, characterization and antitumor activity of two new dipyridinium ylide based lanthanide(III) complexes

Abstract Two new dinuclear lanthanide(III) complexes, La-DPY and Nd-DPY , with the stoichiometric formula [{Ln(Et 3 N)(SO 4 )} 2 (μ-DPY)(μ 4 -SO 4 )] (Ln = La, Nd; DPY = ylide form of DPB, Et 3 N = triethylamine), were obtained through the reaction of N -heterocylic diquaternary salt N,N’ -diphenacyl-4,4′-dipyridinium dibromide (DPB) and lanthanide(III) sulfate in methanol, in the presence of triethylamine. The obtained complexes were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, elemental analysis, UV–vis spectroscopy, thermogravimetric analysis and powder X-ray diffraction. Scanning electron microscopy (SEM) was used to investigate the morphology and particles size of the complexes, confirming that their particles are quite homogenous and uniform. The antitumor activity of the complexes was evaluated in the human cancer cells MCF7 and A2780 and compared to cisplatin, the metal-based drug in cancer therapy. The complexes were found to induce apoptotic cell death and, to a lesser extent, production of ROS, although these are not the unique mechanisms of action. In conclusion, we anticipate that these types of Ln(III) complexes have potential and could be further explored for applications as antitumor agents.