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
A cyclometalated greenish-yellow emitter 2,3-diphenylimidazo[1,2-a]pyridine iridium(Ill) complex is successfully synthesized and used to fabricate phosphorescent organic light-emitting diodes. The optimized device e...A cyclometalated greenish-yellow emitter 2,3-diphenylimidazo[1,2-a]pyridine iridium(Ill) complex is successfully synthesized and used to fabricate phosphorescent organic light-emitting diodes. The optimized device exhibits a greenish-yellow emission with the peak at 523nm and a strong shoulder at 557nm, corresponding to Commission Internationale de l'Eclairage coordinates of (0.38, 0.68). The full width at half maximum of the device is 93 nm, which is broader than the fac-tris(2-phenylpyridine)iridium [Ir(ppy)3] based reference device of 78 nm. Meanwhile, a maximum current efficiency of 62.6 cd/A (47.51m/W) is obtained. This result is higher than a maximum current efficiency of 54.8 cd/A (431m/W) of the Ir(ppy)a based device. The results indicate that this new iridium complex may have potential applications in fabricating high color rendering index white organic light emitting diodes.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
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
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.Th...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.展开更多
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...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.展开更多
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 ma...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.展开更多
In this work, a near-infrared (NIR) phosphorescent probe for F- based on a cationic Ir(III) complex [Ir(Bpq)2(quqo)]PF6 (1) with dimesitylboryl (Mes2B) groups on the cyclometalated CAN ligands (Bpq) and 2-(quinolin-2-...In this work, a near-infrared (NIR) phosphorescent probe for F- based on a cationic Ir(III) complex [Ir(Bpq)2(quqo)]PF6 (1) with dimesitylboryl (Mes2B) groups on the cyclometalated CAN ligands (Bpq) and 2-(quinolin-2-yl)quinoxaline (quqo) as NAN ligand was designed and synthesized. The excited state properties of 1 were investigated in detail using molecular orbital calculations and experimental methods. Upon excitation, complex 1 shows NIR phosphorescent emission around 680 nm. Interestingly, the complex can be excited with long wavelength around 610 nm. Such long-wavelength excitation can reduce the background emission interference and improve the signal-to-noise ratio. Furthermore, the selective binding between boron atom and F- can give rise to the quenching of emission and realize the near-infrared phosphorescent sensing for F-. We wish that the results reported herein will be helpful for the further design of excellent near-infrared phosphorescent probes based on heavy-metal complexes.展开更多
A new cyclometalated iridium(Ⅲ) complex [Ir(2-pq)2(HPIP)]C1 (lrl, 2-pq=3-phenylisoquinoline, HPIP= 2-(2-hydroxyphenyl)imidazo[4,5-f] 1,10-phenanthroline) was synthesized and applied to image mitochondria in...A new cyclometalated iridium(Ⅲ) complex [Ir(2-pq)2(HPIP)]C1 (lrl, 2-pq=3-phenylisoquinoline, HPIP= 2-(2-hydroxyphenyl)imidazo[4,5-f] 1,10-phenanthroline) was synthesized and applied to image mitochondria in living cells. Irl displayed excellent ability to selectively accumulate in mitochondria of live cells with no requirement of replacement of the culture medium. Due to Irl exhibiting better photostability than the commercially available mitochondrial trackers, this complex could be applicable for the imaging and tracking of the mitochondrial mor- phological changes over long periods of time. In addition, in vitro cytotoxicity investigation revealed that it! showed negligible cytotoxicity at the concentrations employed. Based on these, Irl is suitable for organelle-selective imaging in living cells.展开更多
采用真空热蒸镀方法以4,4′-bis(carbazol-9-yl)biphenyl(CBP)为主体材料、以bis[2-(4-tert-butylphenyl)benzothiazolato-N,C2′]iridium(acetylacetonate)[(t-bt)2Ir(acac)]磷光染料为掺杂剂构成黄色发光层,制备了高效白光的有机电致...采用真空热蒸镀方法以4,4′-bis(carbazol-9-yl)biphenyl(CBP)为主体材料、以bis[2-(4-tert-butylphenyl)benzothiazolato-N,C2′]iridium(acetylacetonate)[(t-bt)2Ir(acac)]磷光染料为掺杂剂构成黄色发光层,制备了高效白光的有机电致发光器件(OLEDs).OLEDs的器件结构为indium tin oxide(ITO)/N,N′-bis-(1-naphthyl)-N,N′-biphenyl-1,1′-biphenyl-4,4′-diamine(NPB)/CBP:(t-bt)2Ir(acac)/NPB/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline(BCP)/8-hydroxyquinoline aluminum(Alq3)/Mg∶Ag,从ITO阳极开始的第一层NPB为空穴传输层,第二层超薄的NPB为蓝色发光层,BCP为空穴阻挡层和激子阻挡层,Alq3为电子传输层.结果表明,器件电压在3V启亮,在16.5V时,器件的最高亮度达到15460cd·m-2;在4V时,器件达到最大流明效率为7.5lm·W-1,器件启亮后所发出的白光光谱在低电压时随电压变化有稍微的移动,但是都在白光范围内变化.在电压达到8V后Commission Internationale de l′Eclairage(国际照明委员会)(CIE)色坐标为(0.33,0.32),并且光谱及色坐标稳定,不随电压变化而改变,与最佳的白光坐标(0.33,0.33)几乎重合.同时,从机理上解释了光谱移动和效率衰减的原因,并探讨了载流子陷阱和能量传递的关系.展开更多
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.
文摘A cyclometalated greenish-yellow emitter 2,3-diphenylimidazo[1,2-a]pyridine iridium(Ill) complex is successfully synthesized and used to fabricate phosphorescent organic light-emitting diodes. The optimized device exhibits a greenish-yellow emission with the peak at 523nm and a strong shoulder at 557nm, corresponding to Commission Internationale de l'Eclairage coordinates of (0.38, 0.68). The full width at half maximum of the device is 93 nm, which is broader than the fac-tris(2-phenylpyridine)iridium [Ir(ppy)3] based reference device of 78 nm. Meanwhile, a maximum current efficiency of 62.6 cd/A (47.51m/W) is obtained. This result is higher than a maximum current efficiency of 54.8 cd/A (431m/W) of the Ir(ppy)a based device. The results indicate that this new iridium complex may have potential applications in fabricating high color rendering index white organic light emitting diodes.
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.
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.
基金Supported by the National Natural Science Foundation of China(21572001)the Natural Science Foundation from Bureau of Education of Anhui Province(KJ2013A063)the Anhui Province Undergraduate Innovation and Entrepreneurship Training Program(201510360119)
文摘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.
基金Project(50803008) supported by the National Natural Science Foundation of ChinaProject(2002CB613403) supported by the Ministry of Science and Technology (MOST) of China+1 种基金Project(09JJ6085) supported by the Natural Science Foundation of Hunan Province,ChinaProject(08hjyh02) supported by the Open Project Program of Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education,China
文摘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.
文摘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.
基金financially supported by the National Basic Research Program of China (973 Program, 2009CB930601)National Natural Science Foundation of China (50803028, 20804019 and 61006007)+3 种基金Natural Science Foundation of Jiangsu Province of China (BK2009427)Natural Science Fund for Universities in Jiangsu (10KJB430010)Scien-tific and Technological Activities for Returned Scholars in Nanjing City (NJ209001)Nanjing University of Posts and Telecommunications (NY208045)
文摘In this work, a near-infrared (NIR) phosphorescent probe for F- based on a cationic Ir(III) complex [Ir(Bpq)2(quqo)]PF6 (1) with dimesitylboryl (Mes2B) groups on the cyclometalated CAN ligands (Bpq) and 2-(quinolin-2-yl)quinoxaline (quqo) as NAN ligand was designed and synthesized. The excited state properties of 1 were investigated in detail using molecular orbital calculations and experimental methods. Upon excitation, complex 1 shows NIR phosphorescent emission around 680 nm. Interestingly, the complex can be excited with long wavelength around 610 nm. Such long-wavelength excitation can reduce the background emission interference and improve the signal-to-noise ratio. Furthermore, the selective binding between boron atom and F- can give rise to the quenching of emission and realize the near-infrared phosphorescent sensing for F-. We wish that the results reported herein will be helpful for the further design of excellent near-infrared phosphorescent probes based on heavy-metal complexes.
文摘A new cyclometalated iridium(Ⅲ) complex [Ir(2-pq)2(HPIP)]C1 (lrl, 2-pq=3-phenylisoquinoline, HPIP= 2-(2-hydroxyphenyl)imidazo[4,5-f] 1,10-phenanthroline) was synthesized and applied to image mitochondria in living cells. Irl displayed excellent ability to selectively accumulate in mitochondria of live cells with no requirement of replacement of the culture medium. Due to Irl exhibiting better photostability than the commercially available mitochondrial trackers, this complex could be applicable for the imaging and tracking of the mitochondrial mor- phological changes over long periods of time. In addition, in vitro cytotoxicity investigation revealed that it! showed negligible cytotoxicity at the concentrations employed. Based on these, Irl is suitable for organelle-selective imaging in living cells.
文摘采用真空热蒸镀方法以4,4′-bis(carbazol-9-yl)biphenyl(CBP)为主体材料、以bis[2-(4-tert-butylphenyl)benzothiazolato-N,C2′]iridium(acetylacetonate)[(t-bt)2Ir(acac)]磷光染料为掺杂剂构成黄色发光层,制备了高效白光的有机电致发光器件(OLEDs).OLEDs的器件结构为indium tin oxide(ITO)/N,N′-bis-(1-naphthyl)-N,N′-biphenyl-1,1′-biphenyl-4,4′-diamine(NPB)/CBP:(t-bt)2Ir(acac)/NPB/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline(BCP)/8-hydroxyquinoline aluminum(Alq3)/Mg∶Ag,从ITO阳极开始的第一层NPB为空穴传输层,第二层超薄的NPB为蓝色发光层,BCP为空穴阻挡层和激子阻挡层,Alq3为电子传输层.结果表明,器件电压在3V启亮,在16.5V时,器件的最高亮度达到15460cd·m-2;在4V时,器件达到最大流明效率为7.5lm·W-1,器件启亮后所发出的白光光谱在低电压时随电压变化有稍微的移动,但是都在白光范围内变化.在电压达到8V后Commission Internationale de l′Eclairage(国际照明委员会)(CIE)色坐标为(0.33,0.32),并且光谱及色坐标稳定,不随电压变化而改变,与最佳的白光坐标(0.33,0.33)几乎重合.同时,从机理上解释了光谱移动和效率衰减的原因,并探讨了载流子陷阱和能量传递的关系.