Bis(ferrocenylimine)palladium(II) and platinum(II) complexes: synthesis, molecular structures and evaluation as antitumor agents

Abstract

Compounds (ferrocenyl-2-furylmethyl)imine (L1), (ferrocenyl-2-thiophenemethyl)imine (L2) and (ferrocenyl-2-thiopheneethyl)imine (L3) were synthesized by condensation reactions and obtained in very good yields. Reactions of L1 – L3 with 0.5 equiv of either PdCl2(cod), PdClMe(cod) or K2[PtCl4] gave the new corresponding trans bis(ferrocenylimine)palladium(II) and platinum(II) complexes 1 – 9. The compounds were characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy. The molecular structures of 3 and 6 were determined by single crystal X-ray diffraction analysis. Both structures crystallize in monoclinic P21/n space system. The coordination geometry around the palladium atom in complexes 3 and 6 exhibits a square planar geometry at the palladium atom. Complexes 1, 7 and 9 were evaluated for their cytotoxic activities against human breast (MCF-7) and human ovarian (A2780) cancer cell lines, and they exhibited low cytotoxic activities but comparable to that of cisplatin.