Selective Recognition of DNA Defects By Cyclometalated Ir(III) complexes
Selective detection of DNA defects is an attractive approach for early detection of various tumors and diseases. Ru(II), Rh(III) and hybrid complexes have been reported in this regard. Here, we presented three heteroleptic cyclometalated Ir(III) complexes [Ir(phpy)2(imiphen)]+(Ir-1), [Ir(phpy)2(furphen)]+(Ir-2) and [Ir(phpy)2(faqphen)]+(Ir-3) where imiphen: 2-(1H-imidazol-2-yl)-1Himidazo[ 4,5-f][1,10]phenanthroline; furphen: 2-(furan-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline and faqphen: 6-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-4a,9a-dihydroanthracene-9,10-dione) that have been synthesized and characterized by analytical techniques. All the three complexes recognize the DNA defects with high selectivity as Ir-1 recognizes the abasic site opposite T and CA mismatch, Ir-2 recognizes Ab:G and Ir-3 recognizes the TT mismatch preferably. The results from this study further emphasize that the development of new luminescence probes require fine-tuning of the ligand structure and the choice of metal center to improve the selectivity in recognition of DNA defects.