12354-84-6Relevant articles and documents
Transition metal diamine complexes with antimicrobial activity against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA)
Karpin,Morris,Ngo,Merola,Falkinham Iii
, p. 1471 - 1478 (2015)
Pentaalkylcyclopentadienyl (Cp?R) iridium (Ir) and cobalt (Co) 1,2-diamine complexes were synthesized. Susceptibility of Staphylococcus aureus and recent patient methicillin-resistant S. aureus (MRSA) isolates to the transition metal-diamine complexes were measured by broth microdilution and reported as the MIC and MBC. Hemolytic activities of the transition metal-complexes as well as toxicity toward Vero cells were also measured. The transition metal complex of Cp?RIr with cis-1,2-diaminocyclohexane, had strong antibiotic activity against S. aureus and MRSA (MIC = 4 μg mL-1, MBC = 8 μg mL-1) strains and killed 99% of S. aureus cells in 6 hours. Stronger antibiotic activity was associated with the presence of octyl linked to the cyclopentadienyl group and cyclohexane as the diamine backbone. Activity was greatly diminished by tri- or tetramethylation of the nitrogen of the diamine. A cyclopentadienylcobalt complex of cis-1,2-diaminocyclohexane also showed significant anti-microbial activity against both S. aureus and MRSA strains. The absence of hemolytic activity, Vero cell cytotoxicity and the significant anti-microbial activity of several members of the family of compounds reported suggest this is an area worth further development.
Half-Sandwich Iridium and Ruthenium Complexes: Effective Tracking in Cells and Anticancer Studies
Li, Juanjuan,Guo, Lihua,Tian, Zhenzhen,Zhang, Shumiao,Xu, Zhishan,Han, Yali,Li, Ruixia,Li, Yan,Liu, Zhe
, p. 13552 - 13563 (2018)
Half-sandwich metal-based anticancer complexes suffer from uncertain targets and mechanisms of action. Herein we report the observation of the images of half-sandwich iridium and ruthenium complexes in cells detected by confocal microscopy. The confocal microscopy images showed that the cyclopentadienyl iridium complex 1 mainly accumulated in nuclei in A549 lung cancer cells, whereas the arene ruthenium complex 3 is located in mitochondria and lysosomes, mostly in mitochondria, although both complexes entered A549 cells mainly through energy-dependent active transport. The nuclear morphological changes caused by Ir complex 1 were also detected by confocal microscopy. Ir complex 1 is more potent than cisplatin toward A549 and HeLa cells. DNA binding studies involved interaction with the nucleobases 9-ethylguanine, 9-methyladenine, ctDNA, and plasmid DNA. The determination of bovine serum albumin binding was also performed. Hydrolysis, stability, nucleobase binding, and catalytic NAD+/NADH hydride transfer tests for complexes 1 and 3 were also carried out. Both complexes activated depolarization of mitochondrial membrane potential and intracellular ROS overproduction and induced cell apoptosis. Complex 3 arrested the cell cycle at the G0/G1 phase by inactivation of CDK 4/cyclin D1. This work paves the way to track and monitor half-sandwich metal complexes in cells, shines a light on understanding their mechanism of action, and indicates their potential application as theranostic agents.
Organometallic dithiolene complexes of benzenedithiolate analogues with π-coordinating and π-interacting Cp* ligand
Nomura, Mitsushiro,Tsukano, Eriko,Fujita-Takayama, Chikako,Sugiyama, Toru,Kajitani, Masatsugu
, p. 3116 - 3124 (2009)
Organometallic dithiolene complexes, which were formulated as [Cp*M(dcbdt)] and [Cp*M(dcdmp)] (M = Co, Rh, Ir; Cp* = η5-pentamethylcyclopentadienyl, dcbdt = 4,5-dicyanobenzene-1,2-dithiolate, dcdmp = 2,3-dicyano-5,6-dimercaptopyrazine) were pre
Synthesis, characterization and chemosensitivity studies of half-sandwich ruthenium, rhodium and iridium complexes containing к1(S) and к2(N,S) aroylthiourea ligands
Lapasam, Agreeda,Hussain, Omar,Phillips, Roger M.,Kaminsky, Werner,Kollipara, Mohan Rao
, p. 272 - 280 (2019)
The reaction of [(p-cymene)RuCl2]2 and [Cp*MCl2]2 (M = Rh/Ir) metal precursors with aroylthiourea ligands (L1-L3) yielded a series of neutral mono-dentate complexes 1–9. The neutral mono-dentate coordination of aroylthiourea with metals via S atom was confirmed by single crystal X-ray diffraction study. Further reaction of mono-dentate complexes 1–9 with excess NaN3 in polar solvent resulted in the formation of highly strained four member ring к2(N,S) azido complexes 10–18. Further these complexes were treated with activated alkynes to isolate triazole complexes, but unfortunately the reaction was unsuccessful. All these complexes were fully characterized by various spectroscopic techniques. The molecular structures of the representative complexes have been determined by single crystal X-ray diffraction studies. The molecular structures of the complexes revealed typical piano stool geometry around the metal center. The chemosensitivity activities of the complexes 1–9 evaluated against the cancer cell line HCT-116 (human colorectal carcinoma) and ARPE-19 (human retinal epithelial cells) cell line. Of these, complex 3 was the most potent and whilst its potency was less than cisplatin, its selectivity for cancer as opposed to non-cancer cell lines in vitro was comparable to cisplatin.
Highly active iridium catalyst for hydrogen production from formic acid
Du, Ying,Shen, Yang-Bin,Zhan, Yu-Lu,Ning, Fan-Di,Yan, Liu-Ming,Zhou, Xiao-Chun
, p. 1746 - 1750 (2017)
Formic acid (FA) dehydrogenation has attracted a lot of attentions since it is a convenient method for H2 production. In this work, we designed a self-supporting fuel cell system, in which H2 from FA is supplied into the fuel cell, and the exhaust heat from the fuel cell supported the FA dehydrogenation. In order to realize the system, we synthesized a highly active and selective homogeneous catalyst IrCp*Cl2bpym for FA dehydrogenation. The turnover frequency (TOF) of the catalyst for FA dehydrogenation is as high as 7150?h?1 at 50?°C, and is up to 144,000?h?1 at 90?°C. The catalyst also shows excellent catalytic stability for FA dehydrogenation after several cycles of test. The conversion ratio of FA can achieve 93.2%, and no carbon monoxide is detected in the evolved gas. Therefore, the evolved gas could be applied in the proton exchange membrane fuel cell (PEMFC) directly. This is a potential technology for hydrogen storage and generation. The power density of the PEMFC driven by the evolved gas could approximate to that using pure hydrogen.
A comparative analysis of the in vitro anticancer activity of iridium(III) {η5-C5Me4R} complexes with variable R groups
De Palo, Alice,Draca, Dijana,Murrali, Maria Grazia,Zacchini, Stefano,Pampaloni, Guido,Mijatovic, Sanja,Maksimovic-Ivanic, Danijela,Marchetti, Fabio
, (2021)
Piano-stool iridium complexes based on the pentamethylcyclopentadienyl ligand (Cp*) have been intensively investigated as anticancer drug candidates and hold much promise in this setting. A systematic study aimed at outlining the effect of Cp* mono-derivatization on the antipro-liferative activity is presented here. Thus, the dinuclear complexes [Ir(η5-C5Me4R)Cl(μ-Cl)]2 (R = Me, 1a; R = H, 1b; R = Pr, 1c; R = 4-C6H4F, 1d; R = 4-C6H4OH, 1e), their 2-phenylpyridyl mononuclear derivatives [Ir(η5-C5Me4R)(kN,kCPhPy)Cl] (2a–d), and the dimethylsulfoxide complex [Ir{η5-C5Me4(4-C6H4OH)}Cl2(κS-Me2S=O)] (3) were synthesized, structurally characterized, and assessed for their cytotoxicity towards a panel of six human and rodent cancer cell lines (mouse melanoma, B16; rat glioma, C6; breast adenocarcinoma, MCF-7; colorectal carcinoma, SW620 and HCT116; ovarian carcinoma, A2780) and one primary, human fetal lung fibroblast cell line (MRC5). Complexes 2b (R = H) and 2d (4-C6H4F) emerged as the most active ones and were selected for further investigation. They did not affect the viability of primary mouse peritoneal cells, and their tumor-icidal action arises from the combined influence on cellular proliferation, apoptosis and senescence. The latter is triggered by mitochondrial failure and production of reactive oxygen and nitrogen species.
Evolution of rhodium(III) and iridium(III) chelates as metallonucleases
Vekariya, Pankajkumar A.,Karia, Parag S.,Vaghasiya, Jayraj V.,Soni, Saurabh,Suresh,Patel, Mohan N.
, p. 73 - 84 (2016)
Half sandwich cationic mononuclear rhodium(III) and iridium(III) complexes [(η5-C5Me5)M(L)Cl]Cl·2H2O where L = dipyridylamine (dpa) (M = Rh, 1 and Ir, 2) and dipyridylketone (dpk) (M = Rh, 3 and Ir, 4) have been synthesized and characterized. The structure of a representative complex (1) was authenticated by single crystal X-ray diffraction analysis. Complexes 1–4 have been fully characterized by various physicochemical techniques, namely elemental analysis, spectral (IR, 1H, NMR, UV–Vis), electrochemical studies (cyclic voltammetry (CV) and differential pulse voltammetry (DPV)). Notably, the UV absorption spectral titrations of the synthesized complexes with DNA reveal that the complexes bind to calf thymus DNA (CT-DNA) through the intercalation mode. The DNA solution hydrodynamic volume (viscosity) measurements show that the interaction of the compounds with CT-DNA occurs by classical intercalation. A molecular docking study suggested intercalation between the synthesized compounds and nucleotide base pairs. Cyclic voltammetry studies of the complexes indicate irreversible oxidation and reduction potentials. A gel electrophoresis assay demonstrates the ability of the complexes to cleave pUC19 DNA. The antibacterial activities were assayed against selected Gram(?ve) and Gram(+ve) microorganisms. The cytotoxic properties of the metal complexes have been evaluated using a brine shrimp lethality bioassay. The results suggest that the binding affinity of 1–4 lies in the order 1 > 4?> 2 > 3.
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)
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.
Preparation and reactions of tetrahydrido(pentamethylcyclopentadienyl)iridium: A novel iridium(V) polyhydride
Gilbert, Thomas M.,Bergman, Robert G.
, p. 1458 - 1460 (1983)
The complex (C5(CH3)5)IrH4 (2) has been synthesized and characterized by spectroscopic and analytical methods, including a single-crystal X-ray diffraction study. This compound is a rare example of a formal iridium(V) species; it can be converted to [C5-(CH3)5](PMe3)IrH2 on irradiation in the presence of PMe3, leads to C5(CH3)5-substituted chloro- and hydridochloroiridium dimers on treatment with CCl4, gives [C5(CH3)5]-Ir(CO)2 with CO, and undergoes thermal and photochemical H/D exchange in the presence of D2 gas.
Efficient and rapid synthesis of chlorido-bridged half-sandwich complexes of ruthenium, rhodium, and iridium by microwave heating
Toennemann, Justus,Risse, Julie,Grote, Zacharias,Scopelliti, Rosario,Severin, Kay
, p. 4558 - 4562 (2013)
The dinuclear complexes [(p-cymene)RuCl2]2 and [(cyclopentadienyl)MCl2]2 (M = Ru, Rh, Ir) are important starting materials in organometallic chemistry. The standard synthesis of these complexes involves heating of an alcoholic solution of RuIII, Rh III, or IrIII salts with precursors of the π-ligands for several hours under reflux. Microwave heating allows these complexes to be obtained within a few minutes without compromising the yields. Furthermore, the microwave-assisted syntheses require less solvent and, in some cases, lower amounts of ligand precursors. The important organometallic starting materials [(p-cymene)RuCl2]2 and [(cyclopentadienyl)MCl 2]2 (M = Ru, Rh, Ir) can be obtained by microwave heating. This methodology shortens their synthesis times from several hours to a few minutes. Copyright
Metal iridium-ferrocene Schiff base complex and preparation method thereof
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Paragraph 0077-0078, (2021/07/21)
The invention discloses a metal iridium-ferrocene Schiff base complex as well as a preparation method and anti-cancer application thereof. The structural formula is as shown in formula (I), R1 is hydrogen, methyl or phenyl, R2 is methyl or phenyl, and R3 is hydrogen or methyl. The growth inhibition rate of the target complex on human alveolar basal epithelial cancer cells (A549) and cervical cancer cells (Hela) is tested. Compared with a ferrocene thiosemicarbazide Schiff base ligand, a basic metal iridium dimer and a cis-platinum drug, the target complex shows potential anti-cancer activity, and the synergistic effect of the ferrocene and the metal iridium complex on the anti-cancer activity is proved. The target complex can be accumulated in lysosome tissues of A549 cells and cause lysosome damage, thereby causing cancer cell death.
