A photoactive iridium(III) complex with 3-methyl-2-phenyl pyridine and 1,1-bis(diphenylphosphino)methane: Synthesis, structural characterization and cytotoxicity in breast cancer cells

Abstract

Abstract A photoactive complex [Ir(3m-ppy)2(dppm)Cl] (1; dppm\u2009=\u2009bis(diphenylphosphino)methane, 3\u2009m-Hppy = 3-methyl-2-phenylpyridine), which shows a green luminescence band at 517\u2009nm in DMSO was synthesized from reaction of the dimeric [Ir2(3m-ppy)4Cl2] with dppm under an inert atmosphere. Complex 1 was characterized by 1H NMR, FT-IR, ESI-MS spectroscopies and CHN analysis. Single-crystal X-ray analysis of 1 revealed a distorted octahedral geometry comprising an IrIII center with monodentate dppm, bidentate-C,N 3\u2009m-ppy and chlorido ligands. The electrochemistry of 1 was studied by cyclic voltammetry in 0.1\u2009M NaClO4 in acetonitrile on a glassy carbon working electrode, displaying an oxidation peak of IrIII/IV at 1.2\u2009V. Complex 1 showed anticancer activity against MDA-MB-231, MCF-7 and HCC1937 cell lines of human breast cancer; the respective cytotoxicity factors of 160, 32 and 25 were significantly greater than the cytotoxicity factors obtained with cisplatin.