Synthesis, structure and effects of an azoimine functionalized iridium complex on cancer cells

Abstract

A novel ligand L having azoimine bond with quinoline moiety reacts with [(2-ppy)2Ir(μ-Cl)]2 in dichloromethane medium to produce an iridium(III) complex of composition [Ir(2-ppy)2(L)]. Here, the iridium centre is bound to neutral bidentate N, N donating sites of the ligand (L), where the azo part of L is not involved in chelation. The ligand and complex are characterized by elemental analysis, NMR spectroscopy, ESI-MS mass spectrometry, FTIR, UV–Vis and luminescence spectroscopic techniques. The ligand structure and the geometry around iridium centre of complex [Ir(2-ppy)2(L)] is confirmed by the single-crystal X-ray diffraction (XRD) method. DFT studies were also performed to support the experimental aspects of the complex as well as electronic distribution in molecular orbitals of various energy states. The complex exhibits blue emission band at 428 nm with quantum yield (Φ) 0.136. Further, in vitro analysis of the anticancer activity of the complex was studied mainly with the MCF - 7 cell line. The results showed that the complex have good IC50 values when compared to the standard drug cisplatin.