12354-85-7Relevant articles and documents
Preparation and Bioactivity of Iridium(III) Phenanthroline Complexes with Halide Ions and Pyridine Leaving Groups
Liu, Xicheng,Shao, Mingxiao,Liang, Congcong,Guo, Jinghang,Wang, Guangxuan,Yuan, Xiang-Ai,Jing, Zhihong,Tian, Laijin,Liu, Zhe
, p. 557 - 564 (2020/11/30)
A series of half-sandwich structural iridium(III) phenanthroline (Phen) complexes with halide ions (Cl?, Br?, I?) and pyridine leaving groups ([(η5-CpX)Ir(Phen)Z](PF6)n, Cpx: electron-rich cyclopentadienyl group, Z: leaving group) have been prepared. Target complexes, especially the Cpxbiph (biphenyl-substituted cyclopentadienyl)-based one, showed favourable anticancer activity against human lung cancer (A549) cells; the best one (Ir8) was almost five times that of cisplatin under the same conditions. Compared with complexes involving halide ion leaving groups, the pyridine-based one did not display hydrolysis but effectively caused lysosomal damage, leading to accumulation in the cytosol, inducing an increase in the level of intracellular reactive oxygen species and apoptosis; this indicated an anticancer mechanism of oxidation. Additionally, these complexes could bind to serum albumin through a static quenching mechanism. The data highlight the potential value of half-sandwich iridium(III) phenanthroline complexes as anticancer drugs.
Modulating the water oxidation catalytic activity of iridium complexes by functionalizing the Cp*-ancillary ligand: hints on the nature of the active species
Gatto, Giordano,De Palo, Alice,Carrasco, Ana C.,Pizarro, Ana M.,Zacchini, Stefano,Pampaloni, Guido,Marchetti, Fabio,Macchioni, Alceo
, p. 2885 - 2895 (2021/05/07)
The catalytic activity toward NaIO4driven water oxidation of a series of [RCp*IrCl(μ-Cl)]2dimeric precursors, containing tetramethylcyclopentadienyl ligands with a variable R substituent (H,1; Me,2; Et,3;nPr,4; CH2CH2NH3+,5; Ph,6; 4-C6H4F,7; 4-C6H4OH,8; Bn,9), has been evaluated at 298 K and pH = 7 (with phosphate buffer). For each dimer, the effect of changing the catalyst (1-10 μM) and NaIO4(5-40 mM) concentration has been studied. All precursors exhibit a high activity with TOF values ranging from 101 min?1to 393 min?1and TON values being always those expected assuming a 100% yield. The catalytic activity was strongly affected by the nature of the R substituent. The highest TOF values were observed when R was electron-donating and small. The results of multiple consecutive injection experiments suggest that a fragment of the initial C5Me4R, still bearing the R-substituent, remains attached at iridium in the active species, despite the oxidativein situdegradation of the same ligand. The decrease of TOF in the second and third catalytic runs was completely ascribed to a drop of the redox potential caused by the conversion of IO4?into IO3?, according to the Nernst equation. This hypothesis was verified by performing catalytic experiments in which the initial redox potential (ΔE) was deliberately varied by using water solutions of IO4?/IO3?mixtures at different relative concentrations. Consistently, TOFversusΔEplots show that, for a given catalyst, the same TOF is obtained at a certain redox potential, irrespective of the initial reaction conditions used. All seems to indicate that after a short activation period, during which the transformation of the precursors occurs, individual active species for each dimer form and remain the same also after multiple additions of the sacrificial oxidant. It can be speculated that such active species are small iridium clusters bearing R-functionalized likelyO,O-bidentate ligands.
In Vitro and in Vivo of Triphenylamine-Appended Fluorescent Half-Sandwich Iridium(III) Thiosemicarbazones Antitumor Complexes
Shao, Mingxiao,Yao, Meimei,Liu, Xicheng,Gao, Chao,Liu, Weiyan,Guo, Jinghang,Zong, Jiawen,Sun, Xinzhuo,Liu, Zhe
supporting information, p. 17063 - 17073 (2021/11/16)
Half-sandwiched structure iridium(III) complexes appear to be an attractive organometallic antitumor agents in recent years. Here, four triphenylamine-modified fluorescent half-sandwich iridium(III) thiosemicarbazone (TSC) antitumor complexes were developed. Because of the enol configuration of the TSC ligands, these complexes formed a unique dimeric configuration. Aided by the appropriate fluorescence properties, studies found that complexes could enter tumor cells in an energy-dependent mode, accumulate in lysosomes, and result in the damage of lysosome integrity. Complexes could block the cell cycle, improve the levels of intrastitial reactive oxygen species, and lead to apoptosis, which followed an antitumor mechanism of oxidation. Compared with cisplatin, the antitumor potential in vivo and vitro confirmed that Ir4 could effectively inhibit tumor growth. Meanwhile, Ir4 could avoid detectable side effects in the experiments of safety evaluation. Above all, half-sandwich iridium(III) TSC complexes are expected to be an encouraging candidate for the treatment of malignant tumors.
