AIE-active Ir(iii) complexes as type-I dominant photosensitizers for efficient photodynamic therapy

Abstract

Reactive oxygen species (ROS) including Type I oxygen free radicals and Type II 1O2 generation ability of a photosensitizer (PS) is pivotal for photodynamic therapy. Luminescent Ir(III) complexes are effective...

Cyclometalated Ir(III) Complexes as Lysosome-Targeted Photodynamic Anticancer Agents

“…Cyclometalated Ir­(III) complexes exhibit high fluorescence quantum efficiency and triplet excited-state lifetimes, , which facilitate electron transfer with oxygen, resulting in a high singlet oxygen ( 1 O 2 ) generation quantum yield. , In the past few years, several Ir­(III) complexes functioning as photosensitizers for PDT treatment have been reported. – In particular, the red-emitting cyclometalated Ir­(III) complexes are widely used in PDT. – Furthermore, cyclometalated Ir­(III) complexes containing different carbon–nitrogen (ĈN) and diamine (N̂N) ligands exhibited different phototoxicity indexes (PI, the ratio of the toxic effects in dark and upon light irradiation) for cancer cells, indicating the key role of ligands in the PDT of cyclometalated Ir­(III) complex. – …”

Aggregation-induced emission of cyclometalated rhodium(iii) and iridium(iii) phenylpyridine complexes with ancillary 1,3-diketones

“…35,36 Moreover, there has been a renewed interest in studying rhodium(III) cyclometalates together with their iridium(III) analogues. [37][38][39] Since the first report on cyclometalated iridium(III) complexes exhibiting aggregation-induced emission (AIE), 40 numerous Ir(III) complexes have been shown to be AIE-active, and a wide range of potential applications has been proposed for such complexes [41][42][43][44][45][46][47][48][49][50] and other materials. [51][52][53][54][55][56] Surprisingly, there have been no reports on Rh(III) compounds displaying enhanced emission in the solid state or aggregates.…”

“…Since the first report on cyclometalated iridium( iii ) complexes exhibiting aggregation-induced emission (AIE), 40 numerous Ir( iii ) complexes have been shown to be AIE-active, and a wide range of potential applications has been proposed for such complexes 41–50 and other materials. 51–56 Surprisingly, there have been no reports on Rh( iii ) compounds displaying enhanced emission in the solid state or aggregates.…”

Ligand Dictated Photosensitization of Iridium(III) Dithiocarbamate Complexes for Photodynamic Therapy

“…11−13 However, the clinical applications of many cyclometalated iridium(III) complexes are curtailed by their low quantum yield of 1 O 2 production and short excited state lifetime. 14 Only a few iridium(III) cyclometalated complexes have been studied, which could show high ROS production by undergoing both type I 15,16 and type II PDT with long-lived triplet excited states. 17,18 Hence, there is a need for the development of PSs, which can be activated by both type I and II PDT for effective cancer therapy.…”

“…In inorganic PSs, some organometallic cyclometalated iridium­(III) complexes have already been addressed as potent candidates in the previous literature that has high 1 O 2 production ability, giving them the potency to suppress cancer cells through type II PDT. − However, the clinical applications of many cyclometalated iridium­(III) complexes are curtailed by their low quantum yield of 1 O 2 production and short excited state lifetime . Only a few iridium­(III) cyclometalated complexes have been studied, which could show high ROS production by undergoing both type I , and type II PDT with long-lived triplet excited states. , Hence, there is a need for the development of PSs, which can be activated by both type I and II PDT for effective cancer therapy.…”