Four structurally similar blue phosphorescent iridium complexes with isomerized phenyltriazole(ptz)ligands,[Ir(5-phenyl^(-1)H-1,2,4-triazole)_(3)](1),[Ir(3-phenyl-4H-1,2,4-triazole)_(3)](2),[Ir(4-phenyl^(-1)H-1,2,3-tr...Four structurally similar blue phosphorescent iridium complexes with isomerized phenyltriazole(ptz)ligands,[Ir(5-phenyl^(-1)H-1,2,4-triazole)_(3)](1),[Ir(3-phenyl-4H-1,2,4-triazole)_(3)](2),[Ir(4-phenyl^(-1)H-1,2,3-triazole)_(3)](3),and[Ir(2-phenyl-2H-1,2,3-triazole)_(3)](4),exhibit marked differences in their quantum efficiencies.In order to reveal the coordinating effect of these isomerized ptz ligands on the photophysical properties,density functional theory(DFT)and time-dependent DFT(TD-DFT)calculations were performed to investigate the geometrical and electronic structures,absorption and emission properties,and radiative and nonradiative process of iridium complexes.The calculated results show that the transition nature of an emissive T1 state can be assigned to the mixture of metal-to-ligand charge-transfer(3MLCT)and intraligand charge-transfer(3ILCT)states.The radiative decay rate constants are within the same order of magnitude,and thus the marked difference in the quantum efficiencies is ascribed to the different thermal deactivation pathways via the metal-centered(3MC)states and the nonradiative vibrational relaxation.This work establishes the structure-property relationship for complexes with different ptz isomer ligands,and provides a better understanding of the excited-state behavior of the ptzbased iridium complexes.展开更多
Geometric isomers are very important and interesting in the field of optical materials.In this work,we have designed and synthesized a new series of geometric isomers of iridium complexes featuring three charged(0,-1,...Geometric isomers are very important and interesting in the field of optical materials.In this work,we have designed and synthesized a new series of geometric isomers of iridium complexes featuring three charged(0,-1,-2)ligands,which contain a rigid asymmetric four-membered Ir-N-C-S chelating ring.The reaction of iridium complex precursors(2a and 2b)with an equal amount of the four-membered ring S^N ligand at a low temperature produces the kinetic isomers Ir1K and Ir2K,while a higher temperature leads to the formation of their corresponding thermodynamic isomers Ir1T and Ir2T.The X-ray diffraction analysis shows that the kinetic isomers exhibit a trans-S^N configuration,which is in contrast with the trans-N^N configuration of the thermodynamic isomers,and their coordination bond lengths,bond angles and packing patterns are also quite different.More importantly,all isomers showed efficient deepred emission(619-676 nm),and the thermodynamic isomers have shorter emission wavelengths,longer excited state lifetimes and higher luminescent efficiencies than their corresponding kinetic isomers.Theoretical calculations show that the four-membered ring S^N ligand in the thermodynamic isomers is more involved in the excited state than that in the kinetic isomers,and the^(3)MLCT effects are more pronounced in the thermodynamic isomers.Notably,OLED devices incorporating both thermodynamic and kinetic isomers(Ir2T and Ir2K)as emitting layers can achieve good maximum external quantum efficiencies(EQEs)(5.0%and 4.6%)peaking at 642 nm and 643 nm of the deep-red region with CIE coordinates(0.675,0.323)and(0.668,0.329),respectively,accompanied by a low turn-on voltage(3.0 V).This study provides an important strategy for the design of deep-red emitting geometric isomers of iridium complexes and their photoelectric applications.展开更多
Interest in targeted cancer therapies with fewer side effects has increased in recent years.Photodynamic therapy(PDT)involves the use of photosensitizers(PSs)and light to selectively kill cancer cells,generating highl...Interest in targeted cancer therapies with fewer side effects has increased in recent years.Photodynamic therapy(PDT)involves the use of photosensitizers(PSs)and light to selectively kill cancer cells,generating highly reactive reactive oxygen species(ROS)that damage cellular components.Here,we synthesized a water-soluble iridium metal complex(Ir-PEG-Fn)with folate-targeting characteristics.PEG endowing the iridium complex with the ability to self-assemble into uniform nanoparticles enhances its permeability and retention effect in tumor cells.The elevation in singlet oxygen(^(1)O_(2))levels led to a reduction in the expression levels of glutathione(GSH)and glutathione peroxidase 4(GPX4),while concomitantly augmenting the levels of lipid peroxidase(LPO).These physiological responses effectively suppress tumor growth through the manifestation of ferroptosis events.The combination of ferroptosis and PDT has demonstrated excellent anti-cancer efficacy in tumor models in vivo and in vitro.展开更多
Two luminescent cyclometallated IrIII complexes of the type[Ir(C^N)_(2)(N^N)]^(x)(X=0(1),and X=+1(2))were prepared using methyl 2-phenylquinoline-4-carboxylate as C^N ligands and either a deprotonated or protonated 3-...Two luminescent cyclometallated IrIII complexes of the type[Ir(C^N)_(2)(N^N)]^(x)(X=0(1),and X=+1(2))were prepared using methyl 2-phenylquinoline-4-carboxylate as C^N ligands and either a deprotonated or protonated 3-(2-pyridyl)pyrazole as the N^N chelate.The synthesis followed a well-established and straightforward procedure.Photophysical analysis unveiled their remarkable properties,featuring phosphorescent red and orange emissions attributed to^(3)MLCT and^(3)LLCT transitions,with high emissive quantum yields in degassed DMSO solutions.Importantly,these complexes exhibited dual functionality as potent chemotherapeutic agents and photosensitisers,with their effectiveness tailored to specific cancer cell lines.Phototherapeutic treatment was particularly effective against lung cancer A549 cells,while a chemotherapeutic approach yielded superior results against breast cancer 4T1-luc2 cells.Both complexes primarily targeted lysosomes,leading to cell death through apoptotic pathways,with IC_(50)values in the nanomolar range.Importantly,they demonstrated no cytotoxicity against lymphocytes,mimicking the behaviour observed in healthy cells.Encouragingly,1 and 2 exhibited minimal in vivo toxicity.The most striking finding was the exceptional chemotherapeutic efficacy of complexes 1 and 2 against 4T1-luc2 cells in BALB/c mice.These complexes surpassed the performance of the clinically employed 5-fluorouracil,especially at early tumor stages,significantly retarding 4T1-luc2 proliferation.Further investigations at vascularised and organised tumor stages revealed that complex 1 could reduce tumor size by half compared to untreated mice,which was also confirmed through tumoral weight analysis.While these findings are preliminary,the outstanding performance of these complexes at early tumor stages against breast cancer 4T1-luc2 in vivo,their selective therapeutic feasibility(chemotherapy vs.PDT)tailored to specific cancerous cell lines,and their straightforward synthetic design make them highly attractive candidates for cancer treatment.展开更多
Carbonic anhydrase is an important cancer molecular target and plays important roles in cancer immune functions and maintenance of microenvironments.Herein,three Ir_((III))photosensitizers(Ir1-Ir_(3))targeting carboni...Carbonic anhydrase is an important cancer molecular target and plays important roles in cancer immune functions and maintenance of microenvironments.Herein,three Ir_((III))photosensitizers(Ir1-Ir_(3))targeting carbonic anhydrase IX(CAIX)were designed.Ir1-Ir_(3)exhibit potent antiproliferative activities in colon cancer cells upon irradiation with visible light(425 nm).The most active complex Ir_(3)can photodegrade CAIX under hypoxia,which downregulates the expression of hypoxic inducible factor-1(HIF-1α)and vascular endothelial growth factor(VEGF)to improve cancer immune microenvironments.Ir_(3)can induce pyroptosis of cancer cells through lipid peroxidation,which causes immunogenic cell death(ICD)under hypoxia.In all,we present a new design strategy for small molecules that can improve tumor microenvironments and induce ICD by targeted protein photodegradation,which may bring innovation in the design of novel photoimmunotherapeutic agents.展开更多
Iridium(Ir)(Ⅲ)complexes with sufficient luminous efficiency and narrow full width at half maxima(FWHM)are required urgently for realizing organic light-emitting diodes(OLEDs)simultaneously with high electroluminescen...Iridium(Ir)(Ⅲ)complexes with sufficient luminous efficiency and narrow full width at half maxima(FWHM)are required urgently for realizing organic light-emitting diodes(OLEDs)simultaneously with high electroluminescence efficiency and good color purity.In this work,three novel main ligands incorporating the peripheral large steric hindrance units and rigid structures for efficiently suppressing the intermolecular stacking effect.展开更多
Cyclometalated iridium complexes are widely used in optoelectronic technologies,but creating efficient red emitters remains challenging.Prior investigations have demonstrated the efficiency of electron-rich salicylald...Cyclometalated iridium complexes are widely used in optoelectronic technologies,but creating efficient red emitters remains challenging.Prior investigations have demonstrated the efficiency of electron-rich salicylaldimine and 2-picolinamide ligands in promoting red to deep red luminescence.This work introduces a series of ten new red or deep-red emitting heteroleptic bis-cyclometalated iridium(Ⅲ)complexes supported by eight different ancillary ligands,including some from the salicylaldimine and 2-picolinamide families.Our study reveals that the effectiveness of salicylaldimine ligands at supporting efficient red phosphorescence is dependent on the cyclometalating ligand they are paired with.A more significant finding is that the 2-picolinamide ligands can adopt three different coordination modes.Firstly,the N-propyl-substituted 2-picolinamide proligand can bind to the iridium center in its neutral,protonated form through the pyridyl N and amide O atoms,forming five-membered metallacycles.Furthermore,N-aryl-substituted ligands can coordinate with the iridium center in either N,N’or N(pyridyl),O modes,yielding two structurally distinct isomers.Notably,the change in coordination mode minimally influences emission wavelength while significantly modulating the photoluminescence quantum yield.This study advances our comprehension of how ligand coordination impacts cyclometalated iridium complexes,offering invaluable insights into the design of high-performance red phosphors for potential optoelectronic applications.展开更多
In this work,we describe bis-cyclometalated iridium complexes with efficient deep-red luminescence.Two different cyclometalating(C^N)ligands-1-phenylisoquinoline(piq)and 2-(2-pyridyl)benzothiophene(btp)-are used with ...In this work,we describe bis-cyclometalated iridium complexes with efficient deep-red luminescence.Two different cyclometalating(C^N)ligands-1-phenylisoquinoline(piq)and 2-(2-pyridyl)benzothiophene(btp)-are used with five strongπ-donating ancillary ligands(L^X)to furnish a suite of nine new complexes with the general formula Ir(C^N)_(2)(L^X).Improvements in deep-red photoluminescence quantum yields were accomplished by the incorporation of sterically encumbering substituents onto the ancillary ligand,which can enhance the radiative rate constant(k_(r))and/or reduce the non-radiative rate constant(k_(nr)).Five of the complexes were characterized by X-ray crystallography,and all of them were investigated by in-depth spectroscopic and electrochemical measurements.展开更多
We thoroughly investigated four iridium(III)complexes(Ir(tfmphpm)_(2)(acac),Ir(f-tfmphpm)_(2)(acac),Ir(tfmphpm)_(2)(tpip),and Ir(f-tfmphpm)_(2)(tpip))using 2-(3,5-bis(trifluoromethyl)phenyl)pyrimidine(tfmphpm)and 2-(3...We thoroughly investigated four iridium(III)complexes(Ir(tfmphpm)_(2)(acac),Ir(f-tfmphpm)_(2)(acac),Ir(tfmphpm)_(2)(tpip),and Ir(f-tfmphpm)_(2)(tpip))using 2-(3,5-bis(trifluoromethyl)phenyl)pyrimidine(tfmphpm)and 2-(3,5-bis(trifluoromethyl)phenyl)-5-fluoropyrimidine(f-tfmphpm)as the main ligands and 2,4-pentanedionate(acac)and tetraphenylimidodiphosphinate(tpip)as the ancillary ligands.All complexes showed bluish green emissions peaking at 473–480 nm with very high photoluminescence quantum efficiencies in the range of 85–95%.展开更多
To achieve efficient catalytic hydrogenation of CO_(2)to formate,we employed a transmetallation strategy to develop three novel iridium(Ⅰ)complexes,which feature N‑heterocyclic carbene‑nitrogen‑phosphine ligands(CNP)...To achieve efficient catalytic hydrogenation of CO_(2)to formate,we employed a transmetallation strategy to develop three novel iridium(Ⅰ)complexes,which feature N‑heterocyclic carbene‑nitrogen‑phosphine ligands(CNP)and a 1,5‑cyclooctadiene(cod)molecule:[Ir(cod)(κ^(3)‑CN^(im)P)]Cl(1⁃Cl),[Ir(cod)(κ^(3)‑CN^(im)P)]PF6(1⁃PF_(6)),and[Ir(cod)(κ^(3)‑CNHP)]Cl(2).The^(1)H NMR spectra,^(31)P NMR spectra,and high‑resolution mass spectra verify the successful synthesis of these three Ir(Ⅰ)‑CNP complexes.Furthermore,single‑crystal X‑ray diffraction analysis confirms the coordination geometry of 1⁃PF_(6).The strong Ir—C(NHC)bond suggests that the carbene carbon plays an enhanced anchoring role to iridium due to its strongσ‑donating ability,which helps stabilize the active metal species during CO_(2)hydrogenation.As a result,the Ir(Ⅰ)‑CNP complex exhibits remarkable activity and long catalytic lifetime for the hydrogenation of CO_(2)to formate,reaching a turnover number(TON)of 1.16×10^(6)after 150 h at a high temperature of 170℃,which was a relatively high value among all the Ir complexes.CCDC:2384071,1⁃PF_(6).展开更多
Pure near-infrared(NIR)phosphorescent materials with emission peak larger than 700 nm are of great significance for the development of optoelectronics and biomedicine.We have designed and synthesized two new B-embedde...Pure near-infrared(NIR)phosphorescent materials with emission peak larger than 700 nm are of great significance for the development of optoelectronics and biomedicine.We have designed and synthesized two new B-embedded pure near-infrared(NIR)-emitting iridium complexes(Ir(Bpiq)2acac and Ir(Bpiq)2dpm)with peaks greater than 720 nm.More importantly,they exhibit very narrow phosphorescent emission with full width at half maximum(FWHM)of only about 50 nm(0.12 e V),resulting in a high NIR content(>90%)in their spectrum.In view of better optical property and solubility,the complex Ir(Bpiq)_(2)dpm was used as the emitting layer of a solution-processed OLED device,and achieved good maximum external quantum efficiency(EQE)(2.8%)peaking at 728 nm.This research provides an important strategy for the design of narrowband NIR-emitting phosphorescent iridium complexes and their optoelectronic applications.展开更多
Green-emitting iridium(Ⅲ)complexes were synthesised using chlorobridged dimer(ppy)_(2)Ir_(2)Cl_(2)(ppy)_(2),3-hydroxy-2-methyl-γ-pyranone,2-ethyl-3-hydroxy-4-pyranone,and 5-hydroxy-2-(hydroxymethyl)-1,4-pyranone as ...Green-emitting iridium(Ⅲ)complexes were synthesised using chlorobridged dimer(ppy)_(2)Ir_(2)Cl_(2)(ppy)_(2),3-hydroxy-2-methyl-γ-pyranone,2-ethyl-3-hydroxy-4-pyranone,and 5-hydroxy-2-(hydroxymethyl)-1,4-pyranone as the auxiliary ligand.The structure of the target product was characterised by nuclear magnetic resonance spectroscopy(~1H-NMR),infrared spectroscopy(IR)and mass spectrometry(MS),and its thermal stability,photophysical properties and electrochemical properties were investigated.The results show that the decomposition temperatures of Ir1,Ir2 and Ir3 are 349,292 and 200℃,respectively.The maximum emission wavelength of Ir1,Ir2 and Ir3 dissolved in dichloromethane is 491 nm.The HOMO energy level of Ir1,Ir2 and Ir3 are 5.39,-5.38,and-5.30 eV.The LUMO energy levels are-2.86,-2.85,and-2.80 eV,respectively.展开更多
Three new cyclometalated iridium（m） complexes based on ligands of diphenylquinoline with fluorinated subsfituents were prepared, and characterized by elemental analysis （EA）, ^1H NMR, and mass spectroscopy （MS）....Three new cyclometalated iridium（m） complexes based on ligands of diphenylquinoline with fluorinated subsfituents were prepared, and characterized by elemental analysis （EA）, ^1H NMR, and mass spectroscopy （MS）. The photophysical and electrophosphorescent properties of the complexes were briefly discussed.展开更多
To elucidate the nature of low-lying triplet states and the effect of ligand modifica- tions on the excited-state properties of functional cationic iridium complexes, the solvent- dependent excited-state dynamics of t...To elucidate the nature of low-lying triplet states and the effect of ligand modifica- tions on the excited-state properties of functional cationic iridium complexes, the solvent- dependent excited-state dynamics of two phosphorescent cationic iridium（Ⅲ） complexes, namely [Ir（dph-oxd）2（bpy）]PF6 （1） and [Ir（dph-oxd）2（pzpy）]Pf6 （2）, were investigated by femtosecond and nanosecond transient absorption spectroscopy. Upon photoexcitation to the metal-to-ligand charge-transfer （MLCT） states, the excited-state dynamics shows a rapid process （τ-=0.7-3 ps） for the formation of solvent stabilized 3MLCT states, which significantly depends on the solvent polarity for both 1 and 2. Sequentially, a relatively slow process assigned to the vibrational cooling/geometrical relaxation and a long-lived phospho- rescent emissive state is identified. Due to the different excited-state electronic structures regulated by ancillary ligands, the solvation-induced stabilization of the 3MLCT state in 1 is faster than that in 2. The present results provide a better sight of excited-state relaxation dynamics of ligand-related iridium（Ⅲ） complexes and solvation effects on triplet manifolds.展开更多
Two new fluorinated phenylisoquinoline-based iridium（Ⅲ） complexes,[Ir（f2piq）2（bipy）][PF6]（3a） and[Ir（fmpiq）2（bipy）][PF6]（3b）（f2piq = l-（2,4-difluorophenyl）isoquinoline,fmpiq = 1-（4-fluoro-2-methylph...Two new fluorinated phenylisoquinoline-based iridium（Ⅲ） complexes,[Ir（f2piq）2（bipy）][PF6]（3a） and[Ir（fmpiq）2（bipy）][PF6]（3b）（f2piq = l-（2,4-difluorophenyl）isoquinoline,fmpiq = 1-（4-fluoro-2-methylphenyl）isoquinoline,bipy = 2,2＇-bipyridine）,have been synthesized and fully characterized.Single crystal X-ray diffraction study has been undertaken on complexes 3a and 3b,which show that each adopts the distorted octahedral coordination geometry with the cis-C,C＇ and trans-N,N＇ configuration.The photoluminescence spectra of 3a and 3b exhibit yellow and orange emission maxima at 584 and 600 nm,respectively.The frontier molecular orbital diagrams and the lowest-energy electronic transitions of 3a-3b have been calculated with density functional theory（DFT） and time-dependent DFT（TD-DFT）.The absorption and emission spectra of complex 3b is red-shifted relative to those of complex 3a,as a consequence of the nature of the methyl group.展开更多
Understanding the relationship between structure and properties is critical to the development of solidstate luminescence materials with desired characteristics and performance optimization. In this work, we elaborate...Understanding the relationship between structure and properties is critical to the development of solidstate luminescence materials with desired characteristics and performance optimization. In this work, we elaborately designed and synthesized a pair of mononuclear iridium(Ⅲ) complexes with similar structures but different degrees of cationization. [Ir2-f][2PF_(6)] with two counterions is obtained by simple Nmethylation of the ancillary ligand of [Ir1-f][PF_(6)] which is a classic cationic iridium(Ⅲ) complex. Such a tiny modification results in tremendously different optical properties in dilute solutions and powders.[Ir1-f][PF_(6)] exhibits weak light in solution but enhanced emission in solid-state as well as poly(methyl methacrylate) matrix, indicative of its aggregation-induced emission(AIE) activity. On the sharp contrary, [Ir2-f][2PF_(6)] is an aggregation-caused quenching(ACQ) emitter showing strong emission in the isolated state but nearly nonemissive in aggregation states. Benefiting from the appealing characteristics of mechanochromic luminescence and AIE behavior, [Ir1-f][PF_(6)] has been successfully applied in reversible re-writable data recording and cell imaging. These results might provide deep insights into AIE and ACQ phenomenon of iridium(Ⅲ) complexes and facilitate the development of phosphorescent materials with promising properties.展开更多
Two new iridium complexes with C^N=N type ligand(i.e.,Ir(BFPPya)3{tris[3,6-bis(4-fluorophenyl)pyridazine]iridium(III)}and Ir(BDFPPya)3{tris[3,6-bis(2,4-di-fluorophenyl)pyridazine]iridium(III)})attaching with fluorine ...Two new iridium complexes with C^N=N type ligand(i.e.,Ir(BFPPya)3{tris[3,6-bis(4-fluorophenyl)pyridazine]iridium(III)}and Ir(BDFPPya)3{tris[3,6-bis(2,4-di-fluorophenyl)pyridazine]iridium(III)})attaching with fluorine atoms,were synthesized and the effects of fluorination on the material properties and device performance were investigated.Compared with our previously reported fluorine-free analogue material,that is Ir(BPPya)3{tris[3,6-bis(phenyl)pyridazine]iridium(III)},blue shifts in the emission spectra as well as in the long wavelength region of the absorptions were observed.The photoluminescence quantum yield(PLQY)(0.44 and 0.84 vs.0.29),phosphoresces lifetime(0.88 and 1.31 vs.0.66 gs),and oxidation potential(1.10 and 1.37 vs.0.95 V)increased obviously after fluorinating the ligand.In contrast,the thermal stability of the iridium complexes decreased slightly(Td:435 and 402 vs.440℃).In the density functional theory(DFT)calculations,by comparing the steric shape of the three ligands within one optimized molecule,orientational differences among the complexes were observed.In OLED device studies,bluish green electroluminescence with peak emission of 500 nm,using the electron-transporting host of TPBI[2,2',2"-(1,3,5-benzenetriyl)tris(1-phenyl-lH-benzimidazole)]and the most fluorinated dopant of Ir(BDFPPya)3,was achieved with maximum efficiency of 20.3 cd/A.On one hand this efficiency is not satisfactory considering a high PLQY of 0.84.On the other hand with the similar device structure,that the(HOMO-LUMO)s of all the dopants are wrapped within that of the host TPBI,and all the triplet energies of the dopants are smaller than that of the host TPBI,it is abnormal that the ordering of device efficiencies is contradictory to that of PLQY.Assisting with the phosphorescent spectrum of TPBI and the absorption spectra of the dopant,the contradiction was interpreted reasonably.展开更多
Iridium（Ⅲ） complexes are one of the most important electrophosphorescent dyes with tunable emissions in the range of visible and near infrared lights,high photoluminescence yields and short lifetimes for high-effic...Iridium（Ⅲ） complexes are one of the most important electrophosphorescent dyes with tunable emissions in the range of visible and near infrared lights,high photoluminescence yields and short lifetimes for high-efficiency organic light-emitting diodes（OLED） with 100% exciton harvesting.This review summarizes the recent development of electroluminescent Ir^（3＋） complexes functionalized with host-featured carrier-transporting groups,with emphasis on correlations between functionalization,optoelectronic properties and device performance.According to the introducing approaches,the complexes were sorted with conjugated and aliphatic linkages,as well as the types of functional groups.The modification effect on physical properties and the state-of-the-art device performances were discussed.展开更多
A new cyclometalated iridium（IlI） complex Ir（DPP）3 （DPP=2,3-diphenylpyrazine） was prepared by reaction of DPP with iridium trichloride hydrate under microwave irradiation. The structure of the complex was confir...A new cyclometalated iridium（IlI） complex Ir（DPP）3 （DPP=2,3-diphenylpyrazine） was prepared by reaction of DPP with iridium trichloride hydrate under microwave irradiation. The structure of the complex was confirmed by elemental analysis, ^1H NMR, and mass spectroscopy. The UV-Vis absorption and photoluminescent properties of the complex were investigated. The complex shows strong ^1MLCT （singlet metal to ligand charge-transfer） and aMLCT （triplet metal to ligand charge-transfer） absorption at 382 and 504 nm, respectively. The complex also shows strong photoluminescence at 573 nm at room temperature. These results suggest the complex to be a promising phosphorescent material.展开更多
A new cyclometalated iridium(III) complex with the formula [Ir(DPQ)2(acac)] (DPQ= 2,3-diphenylquinoxaline; acac=acetylacetone) was prepared. The structure of the complex was confirmed by Elemental Analysis (EA), 1H NM...A new cyclometalated iridium(III) complex with the formula [Ir(DPQ)2(acac)] (DPQ= 2,3-diphenylquinoxaline; acac=acetylacetone) was prepared. The structure of the complex was confirmed by Elemental Analysis (EA), 1H NMR, and mass spectroscopy (MS). The UV-vis absorption and photoluminescent properties of the complex were investigated.展开更多
基金support from the National Natural Science Foundation of China(Grants 21073077 and 21173101).
文摘Four structurally similar blue phosphorescent iridium complexes with isomerized phenyltriazole(ptz)ligands,[Ir(5-phenyl^(-1)H-1,2,4-triazole)_(3)](1),[Ir(3-phenyl-4H-1,2,4-triazole)_(3)](2),[Ir(4-phenyl^(-1)H-1,2,3-triazole)_(3)](3),and[Ir(2-phenyl-2H-1,2,3-triazole)_(3)](4),exhibit marked differences in their quantum efficiencies.In order to reveal the coordinating effect of these isomerized ptz ligands on the photophysical properties,density functional theory(DFT)and time-dependent DFT(TD-DFT)calculations were performed to investigate the geometrical and electronic structures,absorption and emission properties,and radiative and nonradiative process of iridium complexes.The calculated results show that the transition nature of an emissive T1 state can be assigned to the mixture of metal-to-ligand charge-transfer(3MLCT)and intraligand charge-transfer(3ILCT)states.The radiative decay rate constants are within the same order of magnitude,and thus the marked difference in the quantum efficiencies is ascribed to the different thermal deactivation pathways via the metal-centered(3MC)states and the nonradiative vibrational relaxation.This work establishes the structure-property relationship for complexes with different ptz isomer ligands,and provides a better understanding of the excited-state behavior of the ptzbased iridium complexes.
基金support from the National Natural Science Foundation of China(22171109 and 22001097)the Natural Science Foundation of Jiangsu Province of China(BK20201003)+1 种基金the Postdoctoral Research Foundation of China(2021M701657)the Shenzhen Science and Technology Program(KQTD20170330110107046).
文摘Geometric isomers are very important and interesting in the field of optical materials.In this work,we have designed and synthesized a new series of geometric isomers of iridium complexes featuring three charged(0,-1,-2)ligands,which contain a rigid asymmetric four-membered Ir-N-C-S chelating ring.The reaction of iridium complex precursors(2a and 2b)with an equal amount of the four-membered ring S^N ligand at a low temperature produces the kinetic isomers Ir1K and Ir2K,while a higher temperature leads to the formation of their corresponding thermodynamic isomers Ir1T and Ir2T.The X-ray diffraction analysis shows that the kinetic isomers exhibit a trans-S^N configuration,which is in contrast with the trans-N^N configuration of the thermodynamic isomers,and their coordination bond lengths,bond angles and packing patterns are also quite different.More importantly,all isomers showed efficient deepred emission(619-676 nm),and the thermodynamic isomers have shorter emission wavelengths,longer excited state lifetimes and higher luminescent efficiencies than their corresponding kinetic isomers.Theoretical calculations show that the four-membered ring S^N ligand in the thermodynamic isomers is more involved in the excited state than that in the kinetic isomers,and the^(3)MLCT effects are more pronounced in the thermodynamic isomers.Notably,OLED devices incorporating both thermodynamic and kinetic isomers(Ir2T and Ir2K)as emitting layers can achieve good maximum external quantum efficiencies(EQEs)(5.0%and 4.6%)peaking at 642 nm and 643 nm of the deep-red region with CIE coordinates(0.675,0.323)and(0.668,0.329),respectively,accompanied by a low turn-on voltage(3.0 V).This study provides an important strategy for the design of deep-red emitting geometric isomers of iridium complexes and their photoelectric applications.
基金supported by the National Natural Science Foundation of China(no.81571812)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(1107047002)+2 种基金the Jiangsu Provincial Medical Youth Talent(QNRC2016075)the Nanjing Medical Science and Technique Development Foundation(ZKX19022)the Jiangsu Provincial High-level Health Talent“Six One Project”(LGY2019005).
文摘Interest in targeted cancer therapies with fewer side effects has increased in recent years.Photodynamic therapy(PDT)involves the use of photosensitizers(PSs)and light to selectively kill cancer cells,generating highly reactive reactive oxygen species(ROS)that damage cellular components.Here,we synthesized a water-soluble iridium metal complex(Ir-PEG-Fn)with folate-targeting characteristics.PEG endowing the iridium complex with the ability to self-assemble into uniform nanoparticles enhances its permeability and retention effect in tumor cells.The elevation in singlet oxygen(^(1)O_(2))levels led to a reduction in the expression levels of glutathione(GSH)and glutathione peroxidase 4(GPX4),while concomitantly augmenting the levels of lipid peroxidase(LPO).These physiological responses effectively suppress tumor growth through the manifestation of ferroptosis events.The combination of ferroptosis and PDT has demonstrated excellent anti-cancer efficacy in tumor models in vivo and in vitro.
基金Agencia Estatal de Investigación PID2022-136861NB-I00/AEI/10.13039/501100011033PID2022-137862NB-I00/AEI/10.13039/501100011033Gobierno de Aragón-Fondo Social Europeo(E07_23R)。
文摘Two luminescent cyclometallated IrIII complexes of the type[Ir(C^N)_(2)(N^N)]^(x)(X=0(1),and X=+1(2))were prepared using methyl 2-phenylquinoline-4-carboxylate as C^N ligands and either a deprotonated or protonated 3-(2-pyridyl)pyrazole as the N^N chelate.The synthesis followed a well-established and straightforward procedure.Photophysical analysis unveiled their remarkable properties,featuring phosphorescent red and orange emissions attributed to^(3)MLCT and^(3)LLCT transitions,with high emissive quantum yields in degassed DMSO solutions.Importantly,these complexes exhibited dual functionality as potent chemotherapeutic agents and photosensitisers,with their effectiveness tailored to specific cancer cell lines.Phototherapeutic treatment was particularly effective against lung cancer A549 cells,while a chemotherapeutic approach yielded superior results against breast cancer 4T1-luc2 cells.Both complexes primarily targeted lysosomes,leading to cell death through apoptotic pathways,with IC_(50)values in the nanomolar range.Importantly,they demonstrated no cytotoxicity against lymphocytes,mimicking the behaviour observed in healthy cells.Encouragingly,1 and 2 exhibited minimal in vivo toxicity.The most striking finding was the exceptional chemotherapeutic efficacy of complexes 1 and 2 against 4T1-luc2 cells in BALB/c mice.These complexes surpassed the performance of the clinically employed 5-fluorouracil,especially at early tumor stages,significantly retarding 4T1-luc2 proliferation.Further investigations at vascularised and organised tumor stages revealed that complex 1 could reduce tumor size by half compared to untreated mice,which was also confirmed through tumoral weight analysis.While these findings are preliminary,the outstanding performance of these complexes at early tumor stages against breast cancer 4T1-luc2 in vivo,their selective therapeutic feasibility(chemotherapy vs.PDT)tailored to specific cancerous cell lines,and their straightforward synthetic design make them highly attractive candidates for cancer treatment.
基金supported by the National Natural Science Foundation of China(No.22022707,22107124,22177142,22107074 and 21837006)the China Postdoctoral Science Foundation(No.2021M693604 and 2021M692188)the Fundamental Research Funds for the Central Universities。
文摘Carbonic anhydrase is an important cancer molecular target and plays important roles in cancer immune functions and maintenance of microenvironments.Herein,three Ir_((III))photosensitizers(Ir1-Ir_(3))targeting carbonic anhydrase IX(CAIX)were designed.Ir1-Ir_(3)exhibit potent antiproliferative activities in colon cancer cells upon irradiation with visible light(425 nm).The most active complex Ir_(3)can photodegrade CAIX under hypoxia,which downregulates the expression of hypoxic inducible factor-1(HIF-1α)and vascular endothelial growth factor(VEGF)to improve cancer immune microenvironments.Ir_(3)can induce pyroptosis of cancer cells through lipid peroxidation,which causes immunogenic cell death(ICD)under hypoxia.In all,we present a new design strategy for small molecules that can improve tumor microenvironments and induce ICD by targeted protein photodegradation,which may bring innovation in the design of novel photoimmunotherapeutic agents.
基金supported by the National Natural Science Foundation of China(22005158)the Program of High Level Talents(No.03083064 and JSSCBS20211122)the Large Instruments Open Foundation of Nantong University,and the Nantong Science and Technology Planning Project(social people’s livelihood)(MS12020048).
文摘Iridium(Ir)(Ⅲ)complexes with sufficient luminous efficiency and narrow full width at half maxima(FWHM)are required urgently for realizing organic light-emitting diodes(OLEDs)simultaneously with high electroluminescence efficiency and good color purity.In this work,three novel main ligands incorporating the peripheral large steric hindrance units and rigid structures for efficiently suppressing the intermolecular stacking effect.
基金the Welch Foundation(Grant E-1887)the National Science Foundation(Grant CHE-1846831)for funding this work.
文摘Cyclometalated iridium complexes are widely used in optoelectronic technologies,but creating efficient red emitters remains challenging.Prior investigations have demonstrated the efficiency of electron-rich salicylaldimine and 2-picolinamide ligands in promoting red to deep red luminescence.This work introduces a series of ten new red or deep-red emitting heteroleptic bis-cyclometalated iridium(Ⅲ)complexes supported by eight different ancillary ligands,including some from the salicylaldimine and 2-picolinamide families.Our study reveals that the effectiveness of salicylaldimine ligands at supporting efficient red phosphorescence is dependent on the cyclometalating ligand they are paired with.A more significant finding is that the 2-picolinamide ligands can adopt three different coordination modes.Firstly,the N-propyl-substituted 2-picolinamide proligand can bind to the iridium center in its neutral,protonated form through the pyridyl N and amide O atoms,forming five-membered metallacycles.Furthermore,N-aryl-substituted ligands can coordinate with the iridium center in either N,N’or N(pyridyl),O modes,yielding two structurally distinct isomers.Notably,the change in coordination mode minimally influences emission wavelength while significantly modulating the photoluminescence quantum yield.This study advances our comprehension of how ligand coordination impacts cyclometalated iridium complexes,offering invaluable insights into the design of high-performance red phosphors for potential optoelectronic applications.
基金the National Science Foundation(CHE-1846831)the Welch Foundation(grant no.E-1887)for funding this research.
文摘In this work,we describe bis-cyclometalated iridium complexes with efficient deep-red luminescence.Two different cyclometalating(C^N)ligands-1-phenylisoquinoline(piq)and 2-(2-pyridyl)benzothiophene(btp)-are used with five strongπ-donating ancillary ligands(L^X)to furnish a suite of nine new complexes with the general formula Ir(C^N)_(2)(L^X).Improvements in deep-red photoluminescence quantum yields were accomplished by the incorporation of sterically encumbering substituents onto the ancillary ligand,which can enhance the radiative rate constant(k_(r))and/or reduce the non-radiative rate constant(k_(nr)).Five of the complexes were characterized by X-ray crystallography,and all of them were investigated by in-depth spectroscopic and electrochemical measurements.
基金supported by the National Natural Science Foundation of China (51773088)the Natural Science Foundation of Jiangsu Province (BY2016075-02).
文摘We thoroughly investigated four iridium(III)complexes(Ir(tfmphpm)_(2)(acac),Ir(f-tfmphpm)_(2)(acac),Ir(tfmphpm)_(2)(tpip),and Ir(f-tfmphpm)_(2)(tpip))using 2-(3,5-bis(trifluoromethyl)phenyl)pyrimidine(tfmphpm)and 2-(3,5-bis(trifluoromethyl)phenyl)-5-fluoropyrimidine(f-tfmphpm)as the main ligands and 2,4-pentanedionate(acac)and tetraphenylimidodiphosphinate(tpip)as the ancillary ligands.All complexes showed bluish green emissions peaking at 473–480 nm with very high photoluminescence quantum efficiencies in the range of 85–95%.
文摘To achieve efficient catalytic hydrogenation of CO_(2)to formate,we employed a transmetallation strategy to develop three novel iridium(Ⅰ)complexes,which feature N‑heterocyclic carbene‑nitrogen‑phosphine ligands(CNP)and a 1,5‑cyclooctadiene(cod)molecule:[Ir(cod)(κ^(3)‑CN^(im)P)]Cl(1⁃Cl),[Ir(cod)(κ^(3)‑CN^(im)P)]PF6(1⁃PF_(6)),and[Ir(cod)(κ^(3)‑CNHP)]Cl(2).The^(1)H NMR spectra,^(31)P NMR spectra,and high‑resolution mass spectra verify the successful synthesis of these three Ir(Ⅰ)‑CNP complexes.Furthermore,single‑crystal X‑ray diffraction analysis confirms the coordination geometry of 1⁃PF_(6).The strong Ir—C(NHC)bond suggests that the carbene carbon plays an enhanced anchoring role to iridium due to its strongσ‑donating ability,which helps stabilize the active metal species during CO_(2)hydrogenation.As a result,the Ir(Ⅰ)‑CNP complex exhibits remarkable activity and long catalytic lifetime for the hydrogenation of CO_(2)to formate,reaching a turnover number(TON)of 1.16×10^(6)after 150 h at a high temperature of 170℃,which was a relatively high value among all the Ir complexes.CCDC:2384071,1⁃PF_(6).
基金support from the National Natural Science Foundation of China(Nos.22171109,52373195 and 22001097)Natural Science Foundation of Jiangsu Province of China(No.BK20201003)+1 种基金the Postdoctoral Research Foundation of China(No.2021M701657)the Opening Project of Key Laboratory of Optoelectronic Chemical Materials and Devices,Ministry of Education,Jianghan University(No.JDGD-202301)。
文摘Pure near-infrared(NIR)phosphorescent materials with emission peak larger than 700 nm are of great significance for the development of optoelectronics and biomedicine.We have designed and synthesized two new B-embedded pure near-infrared(NIR)-emitting iridium complexes(Ir(Bpiq)2acac and Ir(Bpiq)2dpm)with peaks greater than 720 nm.More importantly,they exhibit very narrow phosphorescent emission with full width at half maximum(FWHM)of only about 50 nm(0.12 e V),resulting in a high NIR content(>90%)in their spectrum.In view of better optical property and solubility,the complex Ir(Bpiq)_(2)dpm was used as the emitting layer of a solution-processed OLED device,and achieved good maximum external quantum efficiency(EQE)(2.8%)peaking at 728 nm.This research provides an important strategy for the design of narrowband NIR-emitting phosphorescent iridium complexes and their optoelectronic applications.
文摘Green-emitting iridium(Ⅲ)complexes were synthesised using chlorobridged dimer(ppy)_(2)Ir_(2)Cl_(2)(ppy)_(2),3-hydroxy-2-methyl-γ-pyranone,2-ethyl-3-hydroxy-4-pyranone,and 5-hydroxy-2-(hydroxymethyl)-1,4-pyranone as the auxiliary ligand.The structure of the target product was characterised by nuclear magnetic resonance spectroscopy(~1H-NMR),infrared spectroscopy(IR)and mass spectrometry(MS),and its thermal stability,photophysical properties and electrochemical properties were investigated.The results show that the decomposition temperatures of Ir1,Ir2 and Ir3 are 349,292 and 200℃,respectively.The maximum emission wavelength of Ir1,Ir2 and Ir3 dissolved in dichloromethane is 491 nm.The HOMO energy level of Ir1,Ir2 and Ir3 are 5.39,-5.38,and-5.30 eV.The LUMO energy levels are-2.86,-2.85,and-2.80 eV,respectively.
基金supported by the National Natural Science Foundation of China(No.20371036 and 20474047)the Program for New Century Excellent Talents in University,the Ministry of Education of Chinathe Hubei Province Science Fund for Distinguished Young Scholar(No.2003ABB008).
文摘Three new cyclometalated iridium（m） complexes based on ligands of diphenylquinoline with fluorinated subsfituents were prepared, and characterized by elemental analysis （EA）, ^1H NMR, and mass spectroscopy （MS）. The photophysical and electrophosphorescent properties of the complexes were briefly discussed.
文摘To elucidate the nature of low-lying triplet states and the effect of ligand modifica- tions on the excited-state properties of functional cationic iridium complexes, the solvent- dependent excited-state dynamics of two phosphorescent cationic iridium（Ⅲ） complexes, namely [Ir（dph-oxd）2（bpy）]PF6 （1） and [Ir（dph-oxd）2（pzpy）]Pf6 （2）, were investigated by femtosecond and nanosecond transient absorption spectroscopy. Upon photoexcitation to the metal-to-ligand charge-transfer （MLCT） states, the excited-state dynamics shows a rapid process （τ-=0.7-3 ps） for the formation of solvent stabilized 3MLCT states, which significantly depends on the solvent polarity for both 1 and 2. Sequentially, a relatively slow process assigned to the vibrational cooling/geometrical relaxation and a long-lived phospho- rescent emissive state is identified. Due to the different excited-state electronic structures regulated by ancillary ligands, the solvation-induced stabilization of the 3MLCT state in 1 is faster than that in 2. The present results provide a better sight of excited-state relaxation dynamics of ligand-related iridium（Ⅲ） complexes and solvation effects on triplet manifolds.
基金supported by the National Natural Science Foundation of China(No.21501037)the Natural Science Foundation of Hainan Province(No.20152017)the Science and Research Project of Education Department of Hainan Province(Nos.Hjkj2013-25 and Hnky2015-27)
文摘Two new fluorinated phenylisoquinoline-based iridium（Ⅲ） complexes,[Ir（f2piq）2（bipy）][PF6]（3a） and[Ir（fmpiq）2（bipy）][PF6]（3b）（f2piq = l-（2,4-difluorophenyl）isoquinoline,fmpiq = 1-（4-fluoro-2-methylphenyl）isoquinoline,bipy = 2,2＇-bipyridine）,have been synthesized and fully characterized.Single crystal X-ray diffraction study has been undertaken on complexes 3a and 3b,which show that each adopts the distorted octahedral coordination geometry with the cis-C,C＇ and trans-N,N＇ configuration.The photoluminescence spectra of 3a and 3b exhibit yellow and orange emission maxima at 584 and 600 nm,respectively.The frontier molecular orbital diagrams and the lowest-energy electronic transitions of 3a-3b have been calculated with density functional theory（DFT） and time-dependent DFT（TD-DFT）.The absorption and emission spectra of complex 3b is red-shifted relative to those of complex 3a,as a consequence of the nature of the methyl group.
基金financial support from the National Natural Science Foundation of China(Nos.22175033 and 51902124).
文摘Understanding the relationship between structure and properties is critical to the development of solidstate luminescence materials with desired characteristics and performance optimization. In this work, we elaborately designed and synthesized a pair of mononuclear iridium(Ⅲ) complexes with similar structures but different degrees of cationization. [Ir2-f][2PF_(6)] with two counterions is obtained by simple Nmethylation of the ancillary ligand of [Ir1-f][PF_(6)] which is a classic cationic iridium(Ⅲ) complex. Such a tiny modification results in tremendously different optical properties in dilute solutions and powders.[Ir1-f][PF_(6)] exhibits weak light in solution but enhanced emission in solid-state as well as poly(methyl methacrylate) matrix, indicative of its aggregation-induced emission(AIE) activity. On the sharp contrary, [Ir2-f][2PF_(6)] is an aggregation-caused quenching(ACQ) emitter showing strong emission in the isolated state but nearly nonemissive in aggregation states. Benefiting from the appealing characteristics of mechanochromic luminescence and AIE behavior, [Ir1-f][PF_(6)] has been successfully applied in reversible re-writable data recording and cell imaging. These results might provide deep insights into AIE and ACQ phenomenon of iridium(Ⅲ) complexes and facilitate the development of phosphorescent materials with promising properties.
基金financially supported by the National Natural Science Foundation of China(61077021,61076016)the Nanjing University of Posts and Telecommunications(NY212076,NY212050)
文摘Two new iridium complexes with C^N=N type ligand(i.e.,Ir(BFPPya)3{tris[3,6-bis(4-fluorophenyl)pyridazine]iridium(III)}and Ir(BDFPPya)3{tris[3,6-bis(2,4-di-fluorophenyl)pyridazine]iridium(III)})attaching with fluorine atoms,were synthesized and the effects of fluorination on the material properties and device performance were investigated.Compared with our previously reported fluorine-free analogue material,that is Ir(BPPya)3{tris[3,6-bis(phenyl)pyridazine]iridium(III)},blue shifts in the emission spectra as well as in the long wavelength region of the absorptions were observed.The photoluminescence quantum yield(PLQY)(0.44 and 0.84 vs.0.29),phosphoresces lifetime(0.88 and 1.31 vs.0.66 gs),and oxidation potential(1.10 and 1.37 vs.0.95 V)increased obviously after fluorinating the ligand.In contrast,the thermal stability of the iridium complexes decreased slightly(Td:435 and 402 vs.440℃).In the density functional theory(DFT)calculations,by comparing the steric shape of the three ligands within one optimized molecule,orientational differences among the complexes were observed.In OLED device studies,bluish green electroluminescence with peak emission of 500 nm,using the electron-transporting host of TPBI[2,2',2"-(1,3,5-benzenetriyl)tris(1-phenyl-lH-benzimidazole)]and the most fluorinated dopant of Ir(BDFPPya)3,was achieved with maximum efficiency of 20.3 cd/A.On one hand this efficiency is not satisfactory considering a high PLQY of 0.84.On the other hand with the similar device structure,that the(HOMO-LUMO)s of all the dopants are wrapped within that of the host TPBI,and all the triplet energies of the dopants are smaller than that of the host TPBI,it is abnormal that the ordering of device efficiencies is contradictory to that of PLQY.Assisting with the phosphorescent spectrum of TPBI and the absorption spectra of the dopant,the contradiction was interpreted reasonably.
基金financially supported by NSFC(Nos.51373050 and 61176020)New Century Excellent Talents Supporting Program of MOE(No.NCET-12-0706)+2 种基金Science and Technology Bureau of Heilongjiang Province(Nos.ZD201402 and JC2015002)Education Bureau of Heilongjiang Province(No.2014CJHB005)the Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China(No.141012)
文摘Iridium（Ⅲ） complexes are one of the most important electrophosphorescent dyes with tunable emissions in the range of visible and near infrared lights,high photoluminescence yields and short lifetimes for high-efficiency organic light-emitting diodes（OLED） with 100% exciton harvesting.This review summarizes the recent development of electroluminescent Ir^（3＋） complexes functionalized with host-featured carrier-transporting groups,with emphasis on correlations between functionalization,optoelectronic properties and device performance.According to the introducing approaches,the complexes were sorted with conjugated and aliphatic linkages,as well as the types of functional groups.The modification effect on physical properties and the state-of-the-art device performances were discussed.
文摘A new cyclometalated iridium（IlI） complex Ir（DPP）3 （DPP=2,3-diphenylpyrazine） was prepared by reaction of DPP with iridium trichloride hydrate under microwave irradiation. The structure of the complex was confirmed by elemental analysis, ^1H NMR, and mass spectroscopy. The UV-Vis absorption and photoluminescent properties of the complex were investigated. The complex shows strong ^1MLCT （singlet metal to ligand charge-transfer） and aMLCT （triplet metal to ligand charge-transfer） absorption at 382 and 504 nm, respectively. The complex also shows strong photoluminescence at 573 nm at room temperature. These results suggest the complex to be a promising phosphorescent material.
文摘A new cyclometalated iridium(III) complex with the formula [Ir(DPQ)2(acac)] (DPQ= 2,3-diphenylquinoxaline; acac=acetylacetone) was prepared. The structure of the complex was confirmed by Elemental Analysis (EA), 1H NMR, and mass spectroscopy (MS). The UV-vis absorption and photoluminescent properties of the complex were investigated.
