Benzo[ g ]quinoxaline-Based Complexes [Ir(pbt) 2 (dppn)]Cl and [Ir(pt) 2 (dppn)]Cl: Modulation of Photo-Oxidation Activity and Light-Controlled Luminescence.

Based on benzo[]dipyrido[3,2-a:2',3'-]phenazine (dppn) with photo-oxidation activity, complexes [Ir(pbt)(dppn)]Cl () and [Ir(pt)(dppn)]Cl () have been synthesized (pbtH = 2-phenylbenzothiazole, and ptH = 2-phenylthiazole), with two aims, including studying the influence of the cyclometalating ligands (pbt in , pt in ) on the photo-oxidation activity of these complexes and exploring their photo-oxidation-induced luminescence. Both H nuclear magnetic resonance (NMR) and electrospray (ES) mass spectrometry indicate that the benzo[]quinoxaline moiety in complex can be oxidized at room temperature upon irradiation with 415 nm light. Thus, this complex in CHCl shows photo-oxidation-induced turn-on yellow luminescence. In contrast, complex reveals significant structural decomposition during the process of photo-oxidation due to incorporating a cyclometalating ligand pt instead of pbt in complex . In this paper, we report the photo-oxidation behaviors and the related luminescence modulation in and and discuss the relationship between structure and photo-oxidation activity in these complexes.