Synthesis, structure and biological activities of Pd(II) and Pt(II) complexes with 2-(diphenylphosphino)benzaldehyde 1-adamantoylhydrazone

The reaction of an ethanolic solution of the newly synthesized 2-(diphenylphosphino)benzaldehyde 1-adamantoylhydrazone (HL) with aqueous solutions of K2[MCl4] (M = Pd(II), Pt(II)) resulted in neutral complexes of the general formulae [M(L)Cl]. These complexes have a square-planar structure that was achieved by tridentate PNO coordination of the monoprotonated Schiff base and a chloride ligand. The ligand and its metal complexes were analyzed for their antimicrobial activity and their in vitro cytotoxicity in human larynx carcinoma cells (Hep-2) and non-cancerous human lung fibroblast cells (MRC-5). The platinum(II) complex shows cytotoxicity towards Hep-2 cells comparable to oxaliplatin and exhibited improved selectivity for cancer cells. The ligand and its complexes were characterized by elemental analysis, NMR and IR spectroscopy, and single crystal X-ray diffraction analysis.

Structure of the palladium complex with 2-(diphenylphosphino)benzaldehyde 1-adamantoylhydrazone (left) and diagram of its cytotoxicity (right).Figure optionsDownload as PowerPoint slide