Synthesis and Photoluminescence of a Novel Iridium Complex (BuPhOXD)_2Ir(acac) with Unit of 1, 3, 4-Oxadiazole

A novel cyclometalated iridium complex with 1, 3, 4-oxadiazole moiety was synthesizedand characterized. Its UV and photoluminescent properties were studied. The strong UVabsorption intensity around 462 nm attributed to spin-forbidden triplet metal–ligand charge transferband and photoluminescence at 518 nm were observed. This indicated that achieved iridiumcomplex could be used as an efficient electrophosphorescent material.

Blue-green Phosporescent Iridium Complex with Terdentate Ligand

An ionic iridium（Ⅲ） complex[Ir（F2dpyb）（bzdpp）2Cl][OTf]with 1,3-difluoro-4,6-di（2-pyridinyl） benzene（F2dpybH） terdentate ligand and benzyldiphenylphosphine（bzdpp）ligand was synthesized and characterized.The structure of iridium complex was verified by single-crystal X-ray crystallography.It crystallizes in monoclinic,space group P21/n with a =14.3654（7）,b = 23.0026（10）,c = 15.7964（7） A°,β = 97.6029（11）,V= 5173.9（4） A°3,Z = 4,F（000） =2552,Dc = 1.645 Mg/m^3,Mr = 1281.49 and μ = 0.071 mm^-1.The UV-vis absorption and phosphorescence of the complex were discussed.The complex was ＇aggregation induced emission（AIE）＇ active.It exhibited no emission in CH2Cl2 solution but strong blue-green emission in solid state under ultraviolet light excitation.The complex emitted a strong phosphorescence centered at493 nm when doped in PMMA.Its lifetime is 0.755 μs and quantum yield is approximately 0.134.

Optoelectronic properties of new functionalized heteroleptic iridium complex

A new functionalized heteroleptic iridium complex coordinated with 1-phenylisoquinoline （1-piq） and a functionalized fl-diketone （G1）, Ir（1-piq）2G1, was synthesized and characterized by 1H-NMR, mass spectrometry and elemental analysis. The larger conjugation of the replacement of acetylacetone （acac） by a functionalizedβ-diketonate ligand led to a significant decrease in the HOMO level toward vacuum level, while Ir（1-piq）2G1 and Ir（1-piq）2（acac） showed red phosphorescent emissions of about 620 nm in dichloromethane solution. The phosphorescent polymer light-emitting devices were achieved, with the complexes incorporated with polyfluorene （PFO） as a host polymer doped with 30% of 5-（4-biphenylyl）-2-（4-tert-butylphenyl）-1,3,4-oxadiazole （PBD） as electron transport material. The energy transfer mechanism of the devices was also discussed. The lower EL performance of Ir（1-piq）2G1 is ascribed to the inter-ligand energy transfer, indicating that it is important to control the energy level of the cyclometalated and ancillary ligands.

Novel Iridium Complex with Carbazol-2-yl-β-diketone Derivative:Low-energy Excitation and Red Electrophosphorescent Devices

A novel iridium-complex,（BPPBI） 2 Ir（2-TFDBC）[BPPBI=2-（biphenyl-4-yl）-1-phenyl-1H-benzo[d]imidazole,2-TFDBC=1-（9-ethyl-9H-carbazol-2-yl）-4,4,4-trifluorobutane-1,3-dione],was synthesized,and its structure and component were confirmed by 1 H NMR and element analysis,respectively.UV-Vis absorption and photoluminescent（PL） spectra of（BPPBI） 2 Ir（2-TFDBC） in dichloromethane were investigated.The Ir-complex exhibited a long wavelength excitation of 470 nm,i.e.,low-energy excitation.So,it is a promising candidate for phosphorescent probe and PL material.（BPPBI） 2 Ir（2-TFDBC）-based electroluminescent devices,ITO/MoO 3（10 nm）/NPB（80 nm）/CBP：x（BPPBI） 2 Ir（2-TFDBC）（20 nm）/TPBi（45 nm）/LiF/Al,were fabricated,where x（%） was of 4% or 8% doping concentration（mass fraction）;ITO=indium tin oxides;NBP=N,N＇-bis-（1-naphthalenyl）-N,N＇-bis-phenyl-（1,1＇-biphenyl）4,4＇-diamine,CBP=4,4＇-bis（N-carbazolyl）-1,1＇-biphenyl,TPBi=1,3,5-tris（1-phenyl-1H-benzimidazol-2-yl）benzene.The devices showed a red emission of 620 nm.The maximum current efficiency and brightness were 1.7 cd/A and 4063 cd/m 2 for a device of 8%（mass fraction） doping level,respectively.The moderate luminous efficiency was due to the inadequate energy transfer from the host material to the guest material.

Bone analysis using an aggregation-induced emission-active iridium complex

Fluorescent analysis of bone provides valuable insights into bone structures.However,conventional dyes suffer from low specificity on bone tissue,small stokes shift,short fluorescent lifetime,and aggregation-caused quenching effect,which result in low efficacy and artifacts.In this work,we design an aggregation-induced emission(AIE)-active iridium(III)complex(Ir-BP2)as a highly selective,convenient,nondestructiveness,and dual-mode staining agent for bone analysis.Ir-BP2 containing phosphonate groups selectively binds to hydroxyapatites,the main component of bone matrix,and exhibits turn-on AIE phosphorescence with prolonged lifetime.Ir-BP2 exhibits promising biosafety and offers higher accuracy in staining calcium deposits than conventional Alizarin Red S staining assay when it is employed in real-time monitoring of osteogenesis differentiation process.A ready-to-use staining spray of Ir-BP2 is fabricated.By using fluorescent imaging and lifetime imaging,Ir-BP2 staining provides valuable insights into bone microstructure analysis,microdamage diagnosis,and bone growth state identification.Further,Ir-BP2 is successfully applied on a human spine vertebra for diagnosing bone invasiveness of eosinophilic granuloma,validating its clinical practice.This work presents a powerful tool in bone analysis and will lead to new approaches for the diagnosis and treatment of bone-related diseases.

Metal-ligand cooperative iridium complex catalyzed C-alkylation of oxindole and 1,3-dimethylbarbituric acid using alcohols

A general and high-efficiency C-alkylation of oxindoles and barbituric acids has been developed by a Cp*Ir complex[Cp*Ir(2,20-bpyO)(OH)]Na with a bipyridine-based functional ligand.In particular,H_(2)O was selected as the solvent instead of the organic solvent in this catalytic system.Through mild reaction conditions gave a variety of corresponding alkylated heterocyclic compounds with good to excellent yields.More importantly,the gramscale C-alkylation reaction was successfully carried out with good yield using a common route with only a single purification by column chromatography.

A simple strategy to simultaneously improve the lifetime and activity of classical iridium complex for photocatalytic water-splitting

Herein,we design and synthesize a series of oligomers[Ir(ppy)2(dabpy)-ODPA]n(D1-n)by copolymerization of[Ir(ppy)2(dabpy)][PF6](D2)with 4,4′-Oxydiphthalic anhydride(ODPA),to resolve the problem of simultaneous improvement of sta-bility and activity of classical iridium complex for photocatalytic water-splitting.Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,solid-state nuclear magnetic resonance,and gel permeation chromatography results indicate that the degree of polymerization(n)of D1-n could be tuned by the syn-thesis method.The best photocatalytic performance is reached by D1-n with n at of 2 and/or 3(D1-2/3),which exhibits a photocatalytic lifetime up to 676 h and a photocatalytic hydrogen evolution of 162055.1 Compared with classicalμmol⋅g-1.iridium complex D2,the photocatalytic lifetime of D1-2/3 is about 38 times longer and the photocatalytic activity is 1.3 times higher.Further increase of n leads to a decrease in both photocatalytic lifetime and activity.According to the spectro-scopic characterizations,photoelectrochemical experiments,and density functional theory calculation,the significantly enhanced photocatalytic performance of D1-2/3 originates from the oligomeric structure.The oligomer chain of D1-2/3 with suit-able length acts as a large steric hindrance to reduce the undesired photoinduced decomposition and prolong its lifetime.The possible coupling of adjacent Ir com-plexes in D1-2/3 lowers the energy gap and increases the utilization of visible light,which overcomes the adverse effect of large steric hindrance andfinally improve the activity.This workfirst provides a simple strategy for constructing oligomeric Ir photosensitizers to simultaneously achieve long lifetime and high activity,it will lay the foundation for the design of highly efficient photosensitizers in the future.

Synthesis,crystal structure and photo-physical properties of tris(4-methyl-2,5-diphenylpyridine)iridium for OLED

Organic light-emitting diodes(OLEDs)have important applications in the field of next-generation displays and lighting,and phosphorescent iridium complexes are an important class of electroluminescent phosphorescent materials.In this paper,Ir(bmppy)_(3),tris(4-methyl-2,5-diphenylpyridine)iridium,was synthesized and elvaluted for photo-physical characteristics.Single crystals suitale for X-ray diffraction(XRD)were grown from a mixture solvent of dichloromethane and absolute ethanol.The composition and structur of Ir(bmppy)_(3)were determined by element analysis,NMR spectra and XRD.The complex crystallizes in the monoclinic symmetry with the space group P21/c with a slightly distorted octahedral configuration.As measured by UV-Visible and photoluminescence spectra,Ir(bmppy)_(3) displays a maximum emission at at 527 nm at ambient temperature,a typical green-emitting profile.The complex has potential for application in the OLED industry.

Phosphorescent Cationic Iridium（Ⅲ） Complexes with 1,3,4-Oxadiazole Cyclometalating Ligands： Solvent-Dependent Excited-State Dynamics

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.

Microwave Assisted Synthesis of a New Triplet Iridium（Ⅲ） Pyrazine Complex

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.

Synthesis and optophysical properties of blue-emitting iridium (Ⅲ) complex bearing oxadiazole-based picolinic acid derivative

An iridium （Ⅲ） bis[（4,6-difluorophenyl）pyridinato-N, C^2][6-（6＇-（4＂-（ 5＂-phenyl- 1＂, 3＂, 4＂-oxadiazole-2＂-yl） phenoxy） hexyloxy picolinate） was synthesized and characterized by IH NMR and elementary analysis in order to study the effect of ancillary ligand of the oxadiazole-based picolinic acid derivative on optophysical properties of its iridium complex, and further to obtain an iridium complex with highly-efficient blue emission. The thermal stability, UV absorption and photoluminescent properties of this iridium complex were investigated. Compared with iridium （Ⅲ） bis[（4,6-difluorophenyl）pyridinato-N, C^2]（picolinate） reported as a highly-efficient blue electroluminescent material, this iridium complex bearing an oxadiazole-based picolinic acid derivative presents higher thermal stability, more intense UV absorption at 291 nm and similar photoluminescent spectrum peaked at 469 nm. This indicates that tuning ancillary ligand of picolinic acid with an oxadiazole unit can improve the optophysical properties of its iridium complex.

Synthesis and Characterization of Novel Orange-emitting Iridium(III) Complexes with Diphenylquinoline Ligands Containing Fluorinated Substituent

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.

Synthesis and Photoluminescence of a New Red PhosphorescentIridium(III) Quinoxaline Complex

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.

Synthesis and Luminescent Properties of Iridium Complexes with Reduced Concentration Quenching Effect

Three novel cyclometalated ligands 1-benzyl-2-phenyl-lH-benzoimidazole（BPBM）, 1-（4-methoxy- benzyl）-2-（4-methoxy-phenyl）-lH-benzoimidazole（MBMPB） and 4-[2-（4-dimethylamino-phenyl）-benzoinidazol-1- ylmethyl]-phenyl-dimethyl-amine（DBPA） were designed and synthesized, and the corresponding highly efficiency green-emitting phosphorescent iridium complexes Ir（BPBM）2（acac）（1）, Ir（MBMPB）2（acac）（2） and Ir（DPBA）2（acac） （3） with acetylacetone（acac） as auxiliary ligand were also synthesized. The ligands are functionalized by bulky non-planarity substituents, thus the phosphorescent concentration quenching is substantially suppressed, and all the complexes exhibit bright photoluminescence（PL） in solid state. The photo-physical properties of the three iridium complexes were researched in detail. The results indicate that they have potential application in fabricating non-doped electrophosphorescence device.

Influences of fluorination on homoleptic iridium complexes with C^N=N type ligand to material properties, ligand orientation and OLED performances

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.

Efficient and Low-voltage Phosphorescent Organic Light-emitting Devices Based on Blue Iridium Complex Host

By adopting a phosphorescent host/guest system consisting of blue iridium complex as host and a series of phosphorescent dyes as guest, efficient and low-voltage monochromic organic light-emitting devices（OLEDs） were fabricated. The devices with blue iridium host have higher power efficiency than the device with the conventional host 4,4＇-N,N＇-dicarbazole-biphenyl. The enhancement of the maximum power efficiency in green phosphorescent device can reach 37.2%. Dichromatic white OLED could be achieved by simply adjusting the concentration of the orange dyes. At a brightness of 1000 cd/m2, the power efficiency of the white device is 8.4 lm/W with a color ren- dering index of 76.

Iridium complex of porphycene:a new member of metalloporphycene

Iridium(Ⅲ)porphycene complex was synthesized and structurally characterized for the first time.The introduction of the posttransition iridium(Ⅲ)ion not only significantly enhances the absorption intensity at the end of visible region,but also displays efficient singlet oxygen quantum yield(76%),which is applicable for photodynamic therapy in living cells.

Review on the study of Nonlinear Optics of Iridium Metal Organic Complex

Nonlinear optical materials are one of the key research objects in the field of optics, which mainly research the nonlinear effects of the interaction between luminesce and matter. Compared with inorganic nonlinear optical materials, organic nonlinear materials have outstanding advantages: strong adaptability, high flexibility, low cost, easy modification and damage resistance. In this review, the electric field induced second harmonic generation (EFISH) experimental technology is used to measure and research the nonlinearity of iridium metal complexes. And because of its structural diversity, people can design molecules according to their needs to get the best nonlinear optical response. Organic molecules with large nonlinear coefficients should have the following characteristics: asymmetric charge distribution, the delocalized nature of π electrons, and easy polarization by external electric fields, and a large π conjugated system. In recent years, metal organic compounds have become a leader in the field of optics, mainly because of their very good nonlinear optical properties. In the future, people will do more investigation on the nonlinearity of metal organic complexes. Researchers have shown great interest in iridium metal organic complexes due in particular to their attractive stability and nonlinear activity. This review mainly studies the nonlinear principle, performance test and Measurement of nonlinearity of iridium metal complexes. The nonlinear properties of other metal-metal organic complexes will not be discussed.

Solid-state electrochemiluminescence of a novel iridium(Ⅲ) complex

The solid-state ECL behavior of a water-insoluble bis-cyclometalated （pq）2Ir（N-phMA） complex is presented, in which pq is a 2-phenylquinoline anion and N-phMA is N-phenyl methacrylamide, a monoanionic bidentate ligand. The MWNTs/（pq）2Ir（N-phMA） film, MWNTs/Ru（bpy）3^2＋ film and （pq）2Ir（N-phMA） directly modified glassy carbon electrode were fabricated; only the MWNTs/（pq）2Ir（N-phMA） film can produce steady ECL in the presence of tri-n-propylamine as a coreactant.

取代基位置对2,4-二苯基吡啶类铱磷光配合物光物理性能的影响

铱磷光配合物具有高的发光效率、良好的热稳定性和发光颜色容易调节等优势,在有机发光二极管(OLED)、电化学发光池(LEC)、光催化、肿瘤诊断和传感器等领域有着重要的应用前景,是综合性能最优的电致磷光配合物。其颜色调控主要通过改变主配体和辅助配体的化学结构来实现,如通过改变配体的共轭程度、在配体上引入具有不同供/吸电子能力的取代基、在不同位置引入相同的取代基等方式可以实现发光颜色的调节,其中取代基的位置对铱磷光配合物光物理性能影响的研究较少。研究甲基处于不同取代位置对铱磷光配合物光物理性能的影响,以甲基处于2位和4位或3位和5位的2,4-二苯基吡啶为主配体、2,2,6,6-四甲基庚二酮为辅助配体,合成出2个新的铱磷光配合物(2,4-2Me-dppy)_(2)Ir(tmd)和(3,5-2Me-dppy)_(2)Ir(tmd)。通过元素分析、核磁共振谱和单晶X射线衍射等测试了配合物的组成和空间结构,两个配合物均呈稍微扭曲的八面体构型,空间群分别为C 12/c 1和P-1,晶系分别为单斜和三斜;通过热重分析研究了配合物的热稳定性,两个配合物均具有较好的热稳定性,热分解温度分别为307和318℃;通过紫外可见光谱和光致发光光谱研究了配合物的光物理性能,两个配合物在溶液中发射波长分别为545和572 nm,溶液中量子产率分别为70%和92%。进一步探讨了取代基位置对铱磷光配合物光物理性能的影响,研究发现:甲基所处的位置对2,4-二苯基吡啶类铱磷光配合物的发光颜色和发射波长有着显著的影响。与甲基处于2位和4位得到的铱磷光配合物相比,甲基处于3位和5位时得到的铱配合物的发射波长产生了明显的红移,为纯正的黄光发射,是一种潜在的黄光材料,并有望在OLED照明中得到应用。