Reaction of the non-substituted/substituted unsymmetric pinene-derived complex[Pt(N^C^N')Cl]with the aryl isocyanide 2,6-dimethylphenyl isocyanide(CNXyl)afforded a mixture of two isomeric species:the ionic complex...Reaction of the non-substituted/substituted unsymmetric pinene-derived complex[Pt(N^C^N')Cl]with the aryl isocyanide 2,6-dimethylphenyl isocyanide(CNXyl)afforded a mixture of two isomeric species:the ionic complex[Pt(κ^(3)-N^C^N')(CNXyl)]Cl([A]Cl)and the molecular complex[Pt(κ^(2)-N^C^N')(CNXyl)Cl](B).Isomer B was almost the dominating product.The structures of the isomer B derivatives bearing-CF_(3)and-Cl substituents on the pyridine ring of the pinene moiety(5B and 7B,respectively)have been confirmed by single-crystal X-ray diffraction,revealing a slightly distorted square planar geometry with trans-N_(N^C^N'),CNR configuration(The terminal N atom of theκ^(2)-N^C^N'ligand is trans to the isocyanide ligand CNXyl.).Isomer B is thermodynamically more stable,as confirmed by theoretical calculations.CCDC:2416415,5B;2416414,7B.展开更多
Organoplatinum（Ⅱ） compounds have received enormous attention over the past decades due to their square-planar geometry as well as intriguing photo-physical properties.Self-assembly has emerged as an excellent appro...Organoplatinum（Ⅱ） compounds have received enormous attention over the past decades due to their square-planar geometry as well as intriguing photo-physical properties.Self-assembly has emerged as an excellent approach to create well-ordered supramolecular architectures with tunable properties,which underpin the role of solvent-directed approach for the design of functional materials.In this minireview,the recent advances on supramolecular self-assembly of cyclometalated platinum（Ⅱ） complexes have been discussed.During the self-assembly process,non-covalent Pt-Pt and π-π interactions play crucial roles in controlling the structures and functions of the resulting assemblies.展开更多
A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its plati...A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its platinum complex were investigated. A characteristic metal-ligand charge transfer absorption peak at 439 nm in the UV spectrum and a strong emission peak at 625 nm in the photoluminescence spectrum were observed for this complex in dichloromethane. Cyclic voltammtry (CV) analysis shows that the EHOMO (energy level of the highest occupied molecular orbital) and ELUMO (energy level of the lowest unoccupied molecular orbital) of the platinum complex are about 、5.69 and 、3.25 eV, respectively, indicating that the oxadiazole-based platinum complex has a potential application in electrophosphorescent devices used as a red-emitting material.展开更多
Intracellular p H undertakes critical functions in various biological and pathological processes. It is important to monitor intracellular p H fluctuations for understanding physiological and pathological processes.He...Intracellular p H undertakes critical functions in various biological and pathological processes. It is important to monitor intracellular p H fluctuations for understanding physiological and pathological processes.Here, one aldehyde-bearing cyclometalated iridium(Ⅲ) complex([(4-pba)_(2)Ir(dcphen)]PF_(6), 4-pba = 4-(2-pyridyl) benzaldehyde, dcphen = 4,7-dichloro-1,10-phenanthroline, probe 1) was synthesized and used to track intracellular p H fluctuations. Probe 1 displayed p H-dependent luminescence property in p H range of 1.81–6.81 with an evaluated p Kavalue of 4.30 in BR buffer-DMSO(v:v = 99:1). An intramolecular hydrogen bonds assisted p H-responsive mechanism was proposed for the p H-responsive behavior of probe1. Probe 1 was successfully applied for imaging and tracking p H fluctuations in He La cells under external stimulation with fast response time, good photostability as well as low cytotoxicity and high cell permeability. This work demonstrates that aldehyde-bearing cyclometalated iridium(Ⅲ) complex can be used as alternative p H-responsive probe for real-time tracking intracellular p H fluctuations, which provides a strategy for the design of p H-responsive probe in versatile applications.展开更多
A novel phosphorescent cyclometalated platinum dimer with bis-[2-（p-dodecyloxyphenyl） pyridyll-hexane-1,6-diol as ligand and 1,3-（1-n-hexyl,3-n-heptadecyl）diketone as ancillary ligand was synthesized.The chemical ...A novel phosphorescent cyclometalated platinum dimer with bis-[2-（p-dodecyloxyphenyl） pyridyll-hexane-1,6-diol as ligand and 1,3-（1-n-hexyl,3-n-heptadecyl）diketone as ancillary ligand was synthesized.The chemical structure and liquid crystal property of the dimer were characterized by ~1H NMR,ESl-MS,polarizing optical microscopy（POM） and differential scanning calorimetry （DSC）.The aligned film of title compound on the rubbed polyimide film is intensely emissive at room temperature with emission maximum at 516nm.The luminescence dichroic ratio（（？） ） at 516 nm is 3.1.展开更多
The five-membered ring products and intermediates of cyclometalation reactions are very easily synthesized via donation from a hetero atom to a metal atom, which leads to the very high functionality of the product. Th...The five-membered ring products and intermediates of cyclometalation reactions are very easily synthesized via donation from a hetero atom to a metal atom, which leads to the very high functionality of the product. This functionality is caused by the donation of the hetero atom and various types of metal atoms, halogen atom and other ligands such as alkanes, alkenes, alkynes, Cp, Cp*, aryl groups and heterocyclic compounds. These products have three types of catalytic applications: cyclometalation five-membered ring products as catalysts, cyclometalation five-membered ring intermediates as catalyst agents and cyclometalation five-membered ring intermediates with unconventional substrates and as catalyst actions. Because of the high functionality of these products, the applications of them have been increasing not only as the metathesis in the first and second generations of Hoveyda-Grubbs catalysts but also as in chiral reactions, cross-coupling reactions and polymerization reactions. The above cyclometalation products have been utilized for the production in many industrial fields such as pharmaceuticals, OLEDs, carbon dioxide utilizations, dye-sensitizer solar cells and sensors. We expect that these products would be used for the development of further new industrial products.展开更多
A series of bis-cyclometalated iridium complexes were prepared which combine triazole or NHC-based cyclometalating ligands with substitutedβ-diketiminate(NacNac)ancillary ligands.The HOMO is localized on the NacNac l...A series of bis-cyclometalated iridium complexes were prepared which combine triazole or NHC-based cyclometalating ligands with substitutedβ-diketiminate(NacNac)ancillary ligands.The HOMO is localized on the NacNac ligand and its energy and associated redox potential are determined by the NacNac substitution pattern.The effect of the cyclometalating ligand,relative to the more common 2-phenylpyridine derivatives.展开更多
Thiophenol-substituted 1,10-phenanthroline and three cyclometalating ligands 2-phenylpyridine(ppy),2-(2,4-difluorophenyl)pyridine(F_(2)ppy)and 2-phenylquinoline(pq)were employed to synthesize three organoiridium(Ⅲ)co...Thiophenol-substituted 1,10-phenanthroline and three cyclometalating ligands 2-phenylpyridine(ppy),2-(2,4-difluorophenyl)pyridine(F_(2)ppy)and 2-phenylquinoline(pq)were employed to synthesize three organoiridium(Ⅲ)complexes,1[PF_(6)],2[PF_(6)]and 3[PF_(6)].These complexes exhibit efficient aggregation-induced emission(AIE)in the presence of the poor solvent water and highly dense polyethylene glycol which has been supported by DLS,SEM and TEM.The complexes can be self-assembled into nanoaggregates in aqueous solution facilitated by weak supramolecular interactions,and consequently,the efficient restriction of molecular motion leads to strong AIE.The amorphous solid and single crystal show very bright luminescence compared to the solution.In the solid state,1[PF_(6)],2[PF_(6)],and 3[PF_(6)]show very bright yellow,green,and red luminescence,which is due to the presence of three different cyclometalating ligands,ppy,F_(2)ppy,and pq,respectively.The triplet state TDDFT calculation supported the variant luminescence of these compounds.The single-crystal X-ray structure of these compounds shows that neighbouring complexes in the crystal are connected through both C-H…π and S…F interactions,C-H…F and hydrogen bonds,and the close crystal packing and aggregation in the solid state are the reasons for bright solid-state luminescence.These complexes were employed to selectively detect the nitroaromatic explosive picric acid(PA)in 90%aqueous(H2O:CH_(3)CN;9:1;v/v)solution.For 1[PF_(6)],2[PF_(6)],and 3[PF_(6)],the Stern-Volmer quenching constants(KSV)for the detection of PA were determined to be 8.39×10^(5),5.67×10^(6) and 4.53×10^(5) M^(-1)with a low limit of detection(LOD)of 0.60,0.32,and 3.83 nM,respectively.Finally,a dynamic,photoinduced electron transfer-based(PET)PL quenching mechanism is established with the help of combined spectroscopic and theoretical studies.展开更多
A series of 2-phenylpyridine(ppy)-type cyclometalating ligands containing rigid 5,9-dioxa-13bboranaphtho[3,2,1-de]anthracene(OBA)units have been developed.Together with different ppy-type cyclometalating ligands with ...A series of 2-phenylpyridine(ppy)-type cyclometalating ligands containing rigid 5,9-dioxa-13bboranaphtho[3,2,1-de]anthracene(OBA)units have been developed.Together with different ppy-type cyclometalating ligands with a phenylsulfonyl group(–SO_(2)Ph)substituted at different positions,new unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes have been successfully synthesized.Their photophysical,electrochemical and electroluminescence(EL)behaviors have been fully characterized.In addition,both time-dependent functional theory(TD-DFT)and natural transition orbital(NTO)theoretical results have been obtained to gain insight into the optoelectronic behaviors of these unsymmetric Ir(Ⅲ)complexes with OBA units.The NTO results indicate that the features of the lowest triplet excited states(T_(1))can be delicately tuned by combination between the OBA-based cyclometalating ligand and another ppy-type ligand with the–SO_(2)Ph group.Importantly,these unsymmetric Ir(Ⅲ)complexes can exhibit very high phosphorescence quantum yield(Φ_(p))higher than 0.90 due to the highly rigid OBA unit which can effectively restrain non-radiative processes.In addition,an electron injection/transporting(EI/ET)ability can be conferred to these unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes by both OBA and–SO_(2)Ph moieties.Taking advantage of these merits,organic light-emitting diodes(OLEDs)based on these unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes can show a high maximum external quantum efficiency(ηext)of 12.8%,a current efficiency(η_(L))of 51.1 cd A^(−1),and a power efficiency(η_(P))of 40.5 lm W^(−1) for a yellowish-green device,while EL efficiencies for red devices are 6.8%,13.9 cd A^(−1),and 12.8 lm W^(−1),respectively.All these results indicate the good potential of the rigid OBA unit in developing functional phosphorescent emitters.展开更多
Photoredox catalysis by well-known ruthenium(Ⅱ)polypyridine complexes and the relevant Ir cyclometalated derivatives has become a powerful tool for redox reactions in synthetic organic chemistry,because they can effe...Photoredox catalysis by well-known ruthenium(Ⅱ)polypyridine complexes and the relevant Ir cyclometalated derivatives has become a powerful tool for redox reactions in synthetic organic chemistry,because they can effectively catalyze single-electron-transfer(SET)processes by irradiation with visible light.Remarkably,since 2008,this photocatalytic system has gained importance in radical reactions from the viewpoint of not only a useful and selective protocol but also green chemistry.In this review,we will describe recent developments of radical reactions involving various carbon-centered radicals through photoredox processes mediated by Ru-and Ir-based photocatalysts.展开更多
Cyclometalated Ir(III)complexes hold great promise as an alternative to platinum metallodrugs for the therapy and diagnosis of cancer.However,their low aqueous solubility and poor cell membrane permeability are obstac...Cyclometalated Ir(III)complexes hold great promise as an alternative to platinum metallodrugs for the therapy and diagnosis of cancer.However,their low aqueous solubility and poor cell membrane permeability are obstacles for in vivo applications.Here we have encapsulated for the first time,using polyurethane–polyurea hybrid nanocapsules(NCs),two phosphorescent tris-cyclometalated Ir(III)complexes incorporating deprotonated 2-arylbenzimidazole ligands,Ir1 and Ir2.Ir(III)-Loaded nanocapsules(NC-Ir1 and NC-Ir2)showed a roughly round shape and controlled particle size distribution around 18 nm.The photophysical properties of aqueous solutions of NCs were similar to those of the free complexes in CH2Cl2,which accounts for the hydrophobic and protective environment generated by the nanoparticles around the cargo.Nanoencapsulation had also a positive effect on the cellular uptake of the metallodrugs and NCs were found to be highly cytotoxic towards several cancer cell lines,whereas Ir(III)complexes alone were found to be inactive.展开更多
Platinum complexes of the diimino/carbazolyl NNN pincer ligand have been prepared and characterized.Cyclometallation of the mesityl substituent was observed to occur unexpectedly easily in(NNN)PtOTf,which also catalyz...Platinum complexes of the diimino/carbazolyl NNN pincer ligand have been prepared and characterized.Cyclometallation of the mesityl substituent was observed to occur unexpectedly easily in(NNN)PtOTf,which also catalyzed cyclometallation in(NNN)PtMe.Introduction Pincer complexes have gained in popularity in part because they offer a robust and well-defined framework for study of elementary reactions at transition metal centers.1 Our group,among many others,has been particularly attracted to pincer ligands based on the diarylamido central unit with ortho-positioned side donors(Chart 1).展开更多
Cyclometallated platinum(Ⅱ)complexes,[(C^N^N)Pt^(Ⅱ)(L)]^(n+)(n=0 or 1),have attracted much attention due to their potency as luminescent probes for nucleic acids and anticancer agents.Reported herein are four[(C^N^N...Cyclometallated platinum(Ⅱ)complexes,[(C^N^N)Pt^(Ⅱ)(L)]^(n+)(n=0 or 1),have attracted much attention due to their potency as luminescent probes for nucleic acids and anticancer agents.Reported herein are four[(C^N^N)Pt^(Ⅱ)(L)]^(+)complexes(5-8,L=4-anilinoquinazoline derivative)which exhibit a weak fluorescence emission over 605 to 627 nm upon excitation at 405 nm.The ligation of the cyclometallated platinum cores with EGFR-inhibiting anilinoquinazolines not only confers the resulting complexes with excellent EGFR-inhibiting potency with IC_(50)values at the nanomolar level.展开更多
In recent years,cyclometalated Pt(Ⅱ)complexes with a terdentate ligand have been used as prospective blue phosphorescent materials.For improving these materials further,the introduction of o-carborane is treated as a...In recent years,cyclometalated Pt(Ⅱ)complexes with a terdentate ligand have been used as prospective blue phosphorescent materials.For improving these materials further,the introduction of o-carborane is treated as an excellent strategy to promote the luminescence efficiency.A series of new materials show over 82%phosphorescence quantum yield and good stability,but they are still not fully elucidated.In this work,several different stable o-carborane cages are introduced into the traditional C,N,C-cyclometalated Pt(Ⅱ)complexes in order to explore their influence completely in contrast to the original phenyl ligand from the view of theoretical investigation.Comprehensive analyses of the geometric structure,molecular orbital and configuration information,spin-orbit coupling elements,vibrational modes,etc.have been carried out.More importantly,our theoretical model highlights that the embedded o-carborane ligands will have an impact on the photophysical properties and quantum efficiency of these Pt(Ⅱ)complexes significantly,which can provide a valuable guideline for designing and regulating several aspects of highly efficient blue phosphorescent materials.展开更多
A new class of cyclometalated iridium(III)complexes with imine-N-heterocyclic carbenes(NHC)as ligands were synthesized and fully characterized.One crystal structure is reported.All the six complexes exhibited highly p...A new class of cyclometalated iridium(III)complexes with imine-N-heterocyclic carbenes(NHC)as ligands were synthesized and fully characterized.One crystal structure is reported.All the six complexes exhibited highly potent anticancer activity against A549 cells,HeLa cells,HepG2 cells,GL261 cells and A549R cells.In particular,they were up to 9 and 37 times more potent than clinically used anticancer drug cisplatin towards A549 and A549R cell lines,respectively.Remarkably,mechanism studies showed that the complexes pass into cancer cells through an energy-dependent pathway and cause apoptosis via reactive oxygen species(ROS)generation,mitochondrial membrane potential dysfunction,and lysosomal damage.In addition,complex Ir6 effectively impeded cell migration and colony formation.展开更多
Three new iridium complexes containing 3-(pyridine-2-yl)coumarin as the cyclometalated ligand(L)and 1-(3,5-bis(trifluoromethyl)phenyl)-3-(4-methoxyphenyl)propane-1,3-dione(^(1)L),1-(furan-2-yl)-4,4-dimethylpentane-1,3...Three new iridium complexes containing 3-(pyridine-2-yl)coumarin as the cyclometalated ligand(L)and 1-(3,5-bis(trifluoromethyl)phenyl)-3-(4-methoxyphenyl)propane-1,3-dione(^(1)L),1-(furan-2-yl)-4,4-dimethylpentane-1,3-dione(^(2)L)and 1-(3,4-dimethoxyphenyl)-4,4-dimethylpentane-1,3-dione(^(3)L)as the ancillary ligands,respectively,were synthesized as emissive materials for organic light-emitting devices.展开更多
Organometallic iridium(Ⅲ)complexes with AIE properties have received much attention for their potential in the photoelectric and biomedical fields;however,the development of such materials remains challenging due to ...Organometallic iridium(Ⅲ)complexes with AIE properties have received much attention for their potential in the photoelectric and biomedical fields;however,the development of such materials remains challenging due to the lack of a precise design strategy.Herein,a family of cationic iridium(Ⅲ)complexes with pyridine-azole ancillary ligands,in which 1-(2,4-difluorophenyl)-1H-pyrazole is a cyclometalated ligand,have been strategically synthesized.展开更多
The main difficulties hindering development of a deep-blue phosphorescent cyclometalated Ir(III)complex are insufficient colour purity,i.e.,failure to achieve ideal Commission Internationale de L’Eclairage(CIE)coordi...The main difficulties hindering development of a deep-blue phosphorescent cyclometalated Ir(III)complex are insufficient colour purity,i.e.,failure to achieve ideal Commission Internationale de L’Eclairage(CIE)coordinates of(0.14,0.09),and insufficient emission efficiency and stability.The latter problem is due to the highly energetic and hot excited states of these complexes,which yield faster decomposition.Therefore,control of the excited-state properties of cyclometalated Ir(III)complexes through systematic chemical modification of the ligands is being extensively investigated,with the aim of developing efficient and stable blue phosphorescent materials.The most common strategies towards achievement of a blue phosphorescent cyclometalated Ir(III)complex involve(1)substitution of electronwithdrawing F atoms at the cyclometalating ligands that stabilise the HOMO orbitals and(2)use of a heteroleptic system with electron-rich ancillary ligands bearing a 5-membered ring heterocycle to increase the LUMO energy level.However,the C-F bonds on the cyclometalating ligands have been found to be inherently unstable during device operation;thus,other types of electron-withdrawing groups(e.g.,the cyano,trifluoromethyl,and sulfonyl groups)have been applied.Along with phosphorescence colour tuning to blue,the influence of the ligand structure on the photoluminescence quantum yield(PLQY)is also being intensively investigated.Two major PLQY lowering mechanisms for blue emissive Ir(III)complexes have been identified:(1)the vibronic-coupled non-radiative decay process and(2)crossing from the emissive state to an upper non-emissive ^(3)MC excited state.To enhance the PLQY,mechanism(1)can be suppressed by employing rigid ligand frameworks to restrict intramolecular motion,whereas mechanism(2)can be prevented by destabilising the ^(3)MC state using strongσdonor ligands such as N-heterocyclic carbenes.This review summarises the fundamental photophysics of cyclometalated Ir(III)complexes and surveys design strategies for efficient blue phosphorescent Ir(III)complexes,to provide a guide for future research in this field.展开更多
In the past decade,there has been increasing interest in the applications of cyclometalated iridium(Ⅲ)polypyridine complexes in different areas.Since many of these complexes exhibit interesting photophysical properti...In the past decade,there has been increasing interest in the applications of cyclometalated iridium(Ⅲ)polypyridine complexes in different areas.Since many of these complexes exhibit interesting photophysical properties,they have been utilized in the development of luminescent chemosensors,light-emitting devices,and photovoltaic cells.In addition,a number of organometallic iridium(Ⅲ)polypyridine complexes have been applied in a range of biological studies.In this article,we summarize the applications of a selection of these complexes with a focus on intracellular sensors,organelle-targeting imaging reagents,and metallodrugs.展开更多
The cyclometalated square-planar platinum(Ⅱ)complex 1,bearing a 2-mercaptopyridine 1-oxide chelate ligand,was cocrystallized with any one of the planarπ-hole donating tetrahalo-1,4-benzoquinones QX(X=F,Cl,Br,I)to gi...The cyclometalated square-planar platinum(Ⅱ)complex 1,bearing a 2-mercaptopyridine 1-oxide chelate ligand,was cocrystallized with any one of the planarπ-hole donating tetrahalo-1,4-benzoquinones QX(X=F,Cl,Br,I)to give a series of cocrystals 1·QX;the latter were studied by X-ray crystallography and^(195)Pt MAS-NMR spectroscopy.These studies revealed that all four cocrystals exhibit almost the sameπ-stacked organic-inorganic structural pattern.展开更多
文摘Reaction of the non-substituted/substituted unsymmetric pinene-derived complex[Pt(N^C^N')Cl]with the aryl isocyanide 2,6-dimethylphenyl isocyanide(CNXyl)afforded a mixture of two isomeric species:the ionic complex[Pt(κ^(3)-N^C^N')(CNXyl)]Cl([A]Cl)and the molecular complex[Pt(κ^(2)-N^C^N')(CNXyl)Cl](B).Isomer B was almost the dominating product.The structures of the isomer B derivatives bearing-CF_(3)and-Cl substituents on the pyridine ring of the pinene moiety(5B and 7B,respectively)have been confirmed by single-crystal X-ray diffraction,revealing a slightly distorted square planar geometry with trans-N_(N^C^N'),CNR configuration(The terminal N atom of theκ^(2)-N^C^N'ligand is trans to the isocyanide ligand CNXyl.).Isomer B is thermodynamically more stable,as confirmed by theoretical calculations.CCDC:2416415,5B;2416414,7B.
基金supported by the National Natural Science Foundation of China(No.21274139)the Fundamental Research Funds for the Central Universities(Nos.WK3450000001,WK2060200012)
文摘Organoplatinum（Ⅱ） compounds have received enormous attention over the past decades due to their square-planar geometry as well as intriguing photo-physical properties.Self-assembly has emerged as an excellent approach to create well-ordered supramolecular architectures with tunable properties,which underpin the role of solvent-directed approach for the design of functional materials.In this minireview,the recent advances on supramolecular self-assembly of cyclometalated platinum（Ⅱ） complexes have been discussed.During the self-assembly process,non-covalent Pt-Pt and π-π interactions play crucial roles in controlling the structures and functions of the resulting assemblies.
基金Project(50473046) supported by the National Natural Science Foundation of ChinaProject(204097) supported by the Science Foundation of the Ministry of Education of China+1 种基金Project(04JJ1002) supported by the Outstanding Youth Foundation of Hunan Province,ChinaProject(06JJ2008) supported by the Natural Science Foundation of Hunan Province,China
文摘A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its platinum complex were investigated. A characteristic metal-ligand charge transfer absorption peak at 439 nm in the UV spectrum and a strong emission peak at 625 nm in the photoluminescence spectrum were observed for this complex in dichloromethane. Cyclic voltammtry (CV) analysis shows that the EHOMO (energy level of the highest occupied molecular orbital) and ELUMO (energy level of the lowest unoccupied molecular orbital) of the platinum complex are about 、5.69 and 、3.25 eV, respectively, indicating that the oxadiazole-based platinum complex has a potential application in electrophosphorescent devices used as a red-emitting material.
基金supported by the National Natural Science Foundation of China (Nos. 22074087, 21804106 and 11727813)the Fundamental Research Funds for the Central Universities (No. 2021TS032)。
文摘Intracellular p H undertakes critical functions in various biological and pathological processes. It is important to monitor intracellular p H fluctuations for understanding physiological and pathological processes.Here, one aldehyde-bearing cyclometalated iridium(Ⅲ) complex([(4-pba)_(2)Ir(dcphen)]PF_(6), 4-pba = 4-(2-pyridyl) benzaldehyde, dcphen = 4,7-dichloro-1,10-phenanthroline, probe 1) was synthesized and used to track intracellular p H fluctuations. Probe 1 displayed p H-dependent luminescence property in p H range of 1.81–6.81 with an evaluated p Kavalue of 4.30 in BR buffer-DMSO(v:v = 99:1). An intramolecular hydrogen bonds assisted p H-responsive mechanism was proposed for the p H-responsive behavior of probe1. Probe 1 was successfully applied for imaging and tracking p H fluctuations in He La cells under external stimulation with fast response time, good photostability as well as low cytotoxicity and high cell permeability. This work demonstrates that aldehyde-bearing cyclometalated iridium(Ⅲ) complex can be used as alternative p H-responsive probe for real-time tracking intracellular p H fluctuations, which provides a strategy for the design of p H-responsive probe in versatile applications.
基金supported by the National Natural Science Foundation of China(Nos.20472060 and 21072141)Basic Research Fund of Education Bureau of Sichuan Province,China(No.08ZA040).
文摘A novel phosphorescent cyclometalated platinum dimer with bis-[2-（p-dodecyloxyphenyl） pyridyll-hexane-1,6-diol as ligand and 1,3-（1-n-hexyl,3-n-heptadecyl）diketone as ancillary ligand was synthesized.The chemical structure and liquid crystal property of the dimer were characterized by ~1H NMR,ESl-MS,polarizing optical microscopy（POM） and differential scanning calorimetry （DSC）.The aligned film of title compound on the rubbed polyimide film is intensely emissive at room temperature with emission maximum at 516nm.The luminescence dichroic ratio（（？） ） at 516 nm is 3.1.
文摘The five-membered ring products and intermediates of cyclometalation reactions are very easily synthesized via donation from a hetero atom to a metal atom, which leads to the very high functionality of the product. This functionality is caused by the donation of the hetero atom and various types of metal atoms, halogen atom and other ligands such as alkanes, alkenes, alkynes, Cp, Cp*, aryl groups and heterocyclic compounds. These products have three types of catalytic applications: cyclometalation five-membered ring products as catalysts, cyclometalation five-membered ring intermediates as catalyst agents and cyclometalation five-membered ring intermediates with unconventional substrates and as catalyst actions. Because of the high functionality of these products, the applications of them have been increasing not only as the metathesis in the first and second generations of Hoveyda-Grubbs catalysts but also as in chiral reactions, cross-coupling reactions and polymerization reactions. The above cyclometalation products have been utilized for the production in many industrial fields such as pharmaceuticals, OLEDs, carbon dioxide utilizations, dye-sensitizer solar cells and sensors. We expect that these products would be used for the development of further new industrial products.
基金the National Science Foundation(Grant Number CHE-1846831)the Welch Foundation(Grant Number E-1887)for funding this workComputations performed at CWRU were supported by the Air Force Office of Scientific Research,contract number FA9550-18-1-0247 to T.G.G。
文摘A series of bis-cyclometalated iridium complexes were prepared which combine triazole or NHC-based cyclometalating ligands with substitutedβ-diketiminate(NacNac)ancillary ligands.The HOMO is localized on the NacNac ligand and its energy and associated redox potential are determined by the NacNac substitution pattern.The effect of the cyclometalating ligand,relative to the more common 2-phenylpyridine derivatives.
基金financially supported by DST,India(No.SB/FT/CS/115/2012)the DST-FIST program(No.SR/FST/CS-II/2019/99(C)),Government of India for providing HRMS instrument to the Dept.of Chemistry,NEHU,ShillongNEHU and CSIR(SRF)for their research fellowship.
文摘Thiophenol-substituted 1,10-phenanthroline and three cyclometalating ligands 2-phenylpyridine(ppy),2-(2,4-difluorophenyl)pyridine(F_(2)ppy)and 2-phenylquinoline(pq)were employed to synthesize three organoiridium(Ⅲ)complexes,1[PF_(6)],2[PF_(6)]and 3[PF_(6)].These complexes exhibit efficient aggregation-induced emission(AIE)in the presence of the poor solvent water and highly dense polyethylene glycol which has been supported by DLS,SEM and TEM.The complexes can be self-assembled into nanoaggregates in aqueous solution facilitated by weak supramolecular interactions,and consequently,the efficient restriction of molecular motion leads to strong AIE.The amorphous solid and single crystal show very bright luminescence compared to the solution.In the solid state,1[PF_(6)],2[PF_(6)],and 3[PF_(6)]show very bright yellow,green,and red luminescence,which is due to the presence of three different cyclometalating ligands,ppy,F_(2)ppy,and pq,respectively.The triplet state TDDFT calculation supported the variant luminescence of these compounds.The single-crystal X-ray structure of these compounds shows that neighbouring complexes in the crystal are connected through both C-H…π and S…F interactions,C-H…F and hydrogen bonds,and the close crystal packing and aggregation in the solid state are the reasons for bright solid-state luminescence.These complexes were employed to selectively detect the nitroaromatic explosive picric acid(PA)in 90%aqueous(H2O:CH_(3)CN;9:1;v/v)solution.For 1[PF_(6)],2[PF_(6)],and 3[PF_(6)],the Stern-Volmer quenching constants(KSV)for the detection of PA were determined to be 8.39×10^(5),5.67×10^(6) and 4.53×10^(5) M^(-1)with a low limit of detection(LOD)of 0.60,0.32,and 3.83 nM,respectively.Finally,a dynamic,photoinduced electron transfer-based(PET)PL quenching mechanism is established with the help of combined spectroscopic and theoretical studies.
基金supported by the National Natural Science Foundation of China(21572176,21875179,21602170 and 51803163)the Natural Science Foundation of Shaanxi Province(2019JZ-29 and 2019JQ-188)+3 种基金the China Postdoctoral Science Foundation(2016M600778)the Shaanxi Province Postdoctoral Science Foundation(2017BSHEDZZ03)the Fundamental Research Funds for the Central Universities(xjj2017099,xjj2016061 and cxtd2015003)the Key Laboratory Construction Program of Xi’an Municipal Bureau of Science and Technology(201805056ZD7CG40).
文摘A series of 2-phenylpyridine(ppy)-type cyclometalating ligands containing rigid 5,9-dioxa-13bboranaphtho[3,2,1-de]anthracene(OBA)units have been developed.Together with different ppy-type cyclometalating ligands with a phenylsulfonyl group(–SO_(2)Ph)substituted at different positions,new unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes have been successfully synthesized.Their photophysical,electrochemical and electroluminescence(EL)behaviors have been fully characterized.In addition,both time-dependent functional theory(TD-DFT)and natural transition orbital(NTO)theoretical results have been obtained to gain insight into the optoelectronic behaviors of these unsymmetric Ir(Ⅲ)complexes with OBA units.The NTO results indicate that the features of the lowest triplet excited states(T_(1))can be delicately tuned by combination between the OBA-based cyclometalating ligand and another ppy-type ligand with the–SO_(2)Ph group.Importantly,these unsymmetric Ir(Ⅲ)complexes can exhibit very high phosphorescence quantum yield(Φ_(p))higher than 0.90 due to the highly rigid OBA unit which can effectively restrain non-radiative processes.In addition,an electron injection/transporting(EI/ET)ability can be conferred to these unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes by both OBA and–SO_(2)Ph moieties.Taking advantage of these merits,organic light-emitting diodes(OLEDs)based on these unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes can show a high maximum external quantum efficiency(ηext)of 12.8%,a current efficiency(η_(L))of 51.1 cd A^(−1),and a power efficiency(η_(P))of 40.5 lm W^(−1) for a yellowish-green device,while EL efficiencies for red devices are 6.8%,13.9 cd A^(−1),and 12.8 lm W^(−1),respectively.All these results indicate the good potential of the rigid OBA unit in developing functional phosphorescent emitters.
文摘Photoredox catalysis by well-known ruthenium(Ⅱ)polypyridine complexes and the relevant Ir cyclometalated derivatives has become a powerful tool for redox reactions in synthetic organic chemistry,because they can effectively catalyze single-electron-transfer(SET)processes by irradiation with visible light.Remarkably,since 2008,this photocatalytic system has gained importance in radical reactions from the viewpoint of not only a useful and selective protocol but also green chemistry.In this review,we will describe recent developments of radical reactions involving various carbon-centered radicals through photoredox processes mediated by Ru-and Ir-based photocatalysts.
基金supported by funds from the Spanish Ministerio de Ciencia e Innovación-Agencia Estatal de Investigación(MCI/AEI/10.13039/501100011033)European Regional Development Fund(FEDER)(projects CTQ2017-84779-R,RTI2018-096891-B-I00,PID2020-117508RB-I00 and RED2018-102471-T)+3 种基金the Generalitat de Catalunya(2017 DI 072)Fundación Séneca-Región de Murcia(project 20857/PI/18)E.O.-F.thanks AECC(PRDMU19003ORTE)G.V.thanks the University of Murcia for a grant(R-1034/2016).
文摘Cyclometalated Ir(III)complexes hold great promise as an alternative to platinum metallodrugs for the therapy and diagnosis of cancer.However,their low aqueous solubility and poor cell membrane permeability are obstacles for in vivo applications.Here we have encapsulated for the first time,using polyurethane–polyurea hybrid nanocapsules(NCs),two phosphorescent tris-cyclometalated Ir(III)complexes incorporating deprotonated 2-arylbenzimidazole ligands,Ir1 and Ir2.Ir(III)-Loaded nanocapsules(NC-Ir1 and NC-Ir2)showed a roughly round shape and controlled particle size distribution around 18 nm.The photophysical properties of aqueous solutions of NCs were similar to those of the free complexes in CH2Cl2,which accounts for the hydrophobic and protective environment generated by the nanoparticles around the cargo.Nanoencapsulation had also a positive effect on the cellular uptake of the metallodrugs and NCs were found to be highly cytotoxic towards several cancer cell lines,whereas Ir(III)complexes alone were found to be inactive.
基金the US National Science Foundation(grant CHE-1062840 for the REU site at TAMU and grant CHE-1300299 to O.V.O.)the Welch Foundation(grant A-1717 to O.V.O.)for support of this research.We are also grateful to Ms.Linda Redd for editorial assistance,to Allen Lunsford for assistance with cyclic voltammetry measurements,and to Prof.Andrei Vedernikov for insightful discussions.
文摘Platinum complexes of the diimino/carbazolyl NNN pincer ligand have been prepared and characterized.Cyclometallation of the mesityl substituent was observed to occur unexpectedly easily in(NNN)PtOTf,which also catalyzed cyclometallation in(NNN)PtMe.Introduction Pincer complexes have gained in popularity in part because they offer a robust and well-defined framework for study of elementary reactions at transition metal centers.1 Our group,among many others,has been particularly attracted to pincer ligands based on the diarylamido central unit with ortho-positioned side donors(Chart 1).
基金NSFC(Grant No.21135006,21127901,21575145 and 21621062)the 973 Program of MOST(2013CB531805)for supportProf.Dihua Shangguan and Dr Tao Bing at the Institute of Chemistry,Chinese Academy of Sciences for the gift of the Pu27 quadruplex DNA and BPBC fluorescence probe.
文摘Cyclometallated platinum(Ⅱ)complexes,[(C^N^N)Pt^(Ⅱ)(L)]^(n+)(n=0 or 1),have attracted much attention due to their potency as luminescent probes for nucleic acids and anticancer agents.Reported herein are four[(C^N^N)Pt^(Ⅱ)(L)]^(+)complexes(5-8,L=4-anilinoquinazoline derivative)which exhibit a weak fluorescence emission over 605 to 627 nm upon excitation at 405 nm.The ligation of the cyclometallated platinum cores with EGFR-inhibiting anilinoquinazolines not only confers the resulting complexes with excellent EGFR-inhibiting potency with IC_(50)values at the nanomolar level.
基金supported by the State Key Development Program for Basic Research of China(Grant No.2013CB834801)the Natural Science Foundation of China(Grant No.21573088)+1 种基金the Young Scholar Training Program of Jilin Universitythe Open Project Funding of Beijing National Laboratory for Molecular Sciences(BNLMS).
文摘In recent years,cyclometalated Pt(Ⅱ)complexes with a terdentate ligand have been used as prospective blue phosphorescent materials.For improving these materials further,the introduction of o-carborane is treated as an excellent strategy to promote the luminescence efficiency.A series of new materials show over 82%phosphorescence quantum yield and good stability,but they are still not fully elucidated.In this work,several different stable o-carborane cages are introduced into the traditional C,N,C-cyclometalated Pt(Ⅱ)complexes in order to explore their influence completely in contrast to the original phenyl ligand from the view of theoretical investigation.Comprehensive analyses of the geometric structure,molecular orbital and configuration information,spin-orbit coupling elements,vibrational modes,etc.have been carried out.More importantly,our theoretical model highlights that the embedded o-carborane ligands will have an impact on the photophysical properties and quantum efficiency of these Pt(Ⅱ)complexes significantly,which can provide a valuable guideline for designing and regulating several aspects of highly efficient blue phosphorescent materials.
基金National Natural Science Foundation of China(Grant No.21671118)Taishan Scholars Program。
文摘A new class of cyclometalated iridium(III)complexes with imine-N-heterocyclic carbenes(NHC)as ligands were synthesized and fully characterized.One crystal structure is reported.All the six complexes exhibited highly potent anticancer activity against A549 cells,HeLa cells,HepG2 cells,GL261 cells and A549R cells.In particular,they were up to 9 and 37 times more potent than clinically used anticancer drug cisplatin towards A549 and A549R cell lines,respectively.Remarkably,mechanism studies showed that the complexes pass into cancer cells through an energy-dependent pathway and cause apoptosis via reactive oxygen species(ROS)generation,mitochondrial membrane potential dysfunction,and lysosomal damage.In addition,complex Ir6 effectively impeded cell migration and colony formation.
基金supported by the National Natural Science Foundation of China(Grant 51563014).
文摘Three new iridium complexes containing 3-(pyridine-2-yl)coumarin as the cyclometalated ligand(L)and 1-(3,5-bis(trifluoromethyl)phenyl)-3-(4-methoxyphenyl)propane-1,3-dione(^(1)L),1-(furan-2-yl)-4,4-dimethylpentane-1,3-dione(^(2)L)and 1-(3,4-dimethoxyphenyl)-4,4-dimethylpentane-1,3-dione(^(3)L)as the ancillary ligands,respectively,were synthesized as emissive materials for organic light-emitting devices.
基金support from the National Natural Science Foundation of China(22175033 and 51902124)the Technology Development Plan of Jilin Science and Technology Department(20230101046JC).
文摘Organometallic iridium(Ⅲ)complexes with AIE properties have received much attention for their potential in the photoelectric and biomedical fields;however,the development of such materials remains challenging due to the lack of a precise design strategy.Herein,a family of cationic iridium(Ⅲ)complexes with pyridine-azole ancillary ligands,in which 1-(2,4-difluorophenyl)-1H-pyrazole is a cyclometalated ligand,have been strategically synthesized.
基金supported by the National Research Foundation of Korea(2019R1F1A1058578).
文摘The main difficulties hindering development of a deep-blue phosphorescent cyclometalated Ir(III)complex are insufficient colour purity,i.e.,failure to achieve ideal Commission Internationale de L’Eclairage(CIE)coordinates of(0.14,0.09),and insufficient emission efficiency and stability.The latter problem is due to the highly energetic and hot excited states of these complexes,which yield faster decomposition.Therefore,control of the excited-state properties of cyclometalated Ir(III)complexes through systematic chemical modification of the ligands is being extensively investigated,with the aim of developing efficient and stable blue phosphorescent materials.The most common strategies towards achievement of a blue phosphorescent cyclometalated Ir(III)complex involve(1)substitution of electronwithdrawing F atoms at the cyclometalating ligands that stabilise the HOMO orbitals and(2)use of a heteroleptic system with electron-rich ancillary ligands bearing a 5-membered ring heterocycle to increase the LUMO energy level.However,the C-F bonds on the cyclometalating ligands have been found to be inherently unstable during device operation;thus,other types of electron-withdrawing groups(e.g.,the cyano,trifluoromethyl,and sulfonyl groups)have been applied.Along with phosphorescence colour tuning to blue,the influence of the ligand structure on the photoluminescence quantum yield(PLQY)is also being intensively investigated.Two major PLQY lowering mechanisms for blue emissive Ir(III)complexes have been identified:(1)the vibronic-coupled non-radiative decay process and(2)crossing from the emissive state to an upper non-emissive ^(3)MC excited state.To enhance the PLQY,mechanism(1)can be suppressed by employing rigid ligand frameworks to restrict intramolecular motion,whereas mechanism(2)can be prevented by destabilising the ^(3)MC state using strongσdonor ligands such as N-heterocyclic carbenes.This review summarises the fundamental photophysics of cyclometalated Ir(III)complexes and surveys design strategies for efficient blue phosphorescent Ir(III)complexes,to provide a guide for future research in this field.
基金City University of Hong Kong(Project no.7004210 and 9667090)for financial supportthe Croucher Foundation for a Croucher Senior Research Fellowshipthe receipt of a Postgraduate Studentship administered by City University of Hong Kong.
文摘In the past decade,there has been increasing interest in the applications of cyclometalated iridium(Ⅲ)polypyridine complexes in different areas.Since many of these complexes exhibit interesting photophysical properties,they have been utilized in the development of luminescent chemosensors,light-emitting devices,and photovoltaic cells.In addition,a number of organometallic iridium(Ⅲ)polypyridine complexes have been applied in a range of biological studies.In this article,we summarize the applications of a selection of these complexes with a focus on intracellular sensors,organelle-targeting imaging reagents,and metallodrugs.
基金support of the Russian Science Foundation(project 23-73-01074)is gratefully acknowledged.
文摘The cyclometalated square-planar platinum(Ⅱ)complex 1,bearing a 2-mercaptopyridine 1-oxide chelate ligand,was cocrystallized with any one of the planarπ-hole donating tetrahalo-1,4-benzoquinones QX(X=F,Cl,Br,I)to give a series of cocrystals 1·QX;the latter were studied by X-ray crystallography and^(195)Pt MAS-NMR spectroscopy.These studies revealed that all four cocrystals exhibit almost the sameπ-stacked organic-inorganic structural pattern.
