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
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 li...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.展开更多
The surface pressure-area (pi -A) isotherm of Schiff base aluminium (III), tris (2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium (III) (denoted as Al(TAl2)(3)), on pure water subphase was investigated. The m...The surface pressure-area (pi -A) isotherm of Schiff base aluminium (III), tris (2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium (III) (denoted as Al(TAl2)(3)), on pure water subphase was investigated. The molecular area, 0.48 nm(2), is one-third of expected value that indicated the aggregation took place. The Langmuir-Blodgett (LB) films of Al(TAl2), was transferred and characterized. The AFM image confirmed the formation of aggregates.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
An iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C2][6-(6'-(4''-( 5'''-phenyl- 1''',3''',4'''-oxadiazole- 2 '''-yl) phenoxy) hexyloxy picoli...An iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C2][6-(6'-(4''-( 5'''-phenyl- 1''',3''',4'''-oxadiazole- 2 '''-yl) phenoxy) hexyloxy picolinate) was synthesized and characterized by 1H 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, C2](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.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
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
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 c...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.展开更多
Recent years,many novel complexes have been prepared by using hetero-bidentate ligands.However,complexes with such ligands as 4-vinylpyridine which has two different coordinating sites have not been reported,and only ...Recent years,many novel complexes have been prepared by using hetero-bidentate ligands.However,complexes with such ligands as 4-vinylpyridine which has two different coordinating sites have not been reported,and only a few complexes of Cu(I)have been published^(1-3).The title complex Cu_2(C_5H_4N·CH=CH_2)_3Cl was prepared and characterized by elemental analyses,ICP,IR,and electronic spectra.Its conductivity,oxidation potential and reduction potential were measured.展开更多
The synthesis is and crystal structure are reported for the sheet-like compourd [CU2(oxpn)Fe(CN )5(NO)]. there oxpn is the dianion of M, M'-bis(3-aminopropyl)oxamide. This compound crustallizes in the orthogonal s...The synthesis is and crystal structure are reported for the sheet-like compourd [CU2(oxpn)Fe(CN )5(NO)]. there oxpn is the dianion of M, M'-bis(3-aminopropyl)oxamide. This compound crustallizes in the orthogonal space group Puma. with a=11 .413(4), b=22.242(5), c=7.736(2) A, and Z=4.The structure was refined to conventionat discrepancy factors R=0.047 and Pw=0.054. The Cu(II ) and Fe(III)centers are bridged by oxpn and cyanide, the formal behaves as a his-terdentate tigand bound to cooper(II)ion to form (II) dimers. whereas the latter bridges Cu(II) and Fe(III) centers in both symmetric and asymetric end- to-end bis-monodentate fashions, spreading out along be plane to form a 20 network. The Structure is made up of CuFe unit with Cu(II) and Fe(III) ions locating in a distorted square-based pyramid and a compressed octahedron, respectively.展开更多
Vibrational and H-NMR spectroscopic studies on di-μ-chlorobis(1,5-cyclooctadiene) of iridium(I) and rhodium (I) complexes have been carried out. In addition, the two D2h and D2 structures for both complexes have been...Vibrational and H-NMR spectroscopic studies on di-μ-chlorobis(1,5-cyclooctadiene) of iridium(I) and rhodium (I) complexes have been carried out. In addition, the two D2h and D2 structures for both complexes have been fully optimized. It was expected from the single-molecule vapor-phase density functional theory (DFT) calculation that the D2 structure is more stable by 5 - 6 kcal/mol. While spectroscopic analysis study confirms that in the solid phase, the two complexes retain the higher D2h symmetry. The vibrational wavenumbers of certain modes associated to free 1,5-cyc- looctadiene were observed to be shifted to lower values upon coordination with rhodium or iridium metals. It was also found theoretically that the metal-olefin interaction is slightly more pronounced for iridium metal.展开更多
It has previously been demonstrated that phenanthroline-based ligands used to make gold metallotherapuetics have the ability to exhibit cytotoxicity when not coordinated to the metal center. In an effort to help asses...It has previously been demonstrated that phenanthroline-based ligands used to make gold metallotherapuetics have the ability to exhibit cytotoxicity when not coordinated to the metal center. In an effort to help assess the mechanism by which these ligands may cause tumor cell death, iron binding and removal experiments have been considered. The close linkage between cell proliferation and intracellular iron concentrations suggest that iron deprivation strategies may be a mechanism involved in inhibiting tumor cell growth. With the creation of iron (III) phen complexes, the iron binding abilities of three polypyridal ligands [1,10-phenanthroline (phen), 2,9-dimethyl-1, 10-phenanthroline (methylphen), and 2,9-di-sec-butyl-1, 10-phenanthroline (sec-butylphen)] can be tested via a competition reaction with a known iron chelator. Therefore, iron (III) complexes possessing all three ligands were synthesized. Initial mass spectrometric and infrared absorption data indicate that iron (III) tetrachloride complex ions with protonated phen ligands (RphenH+) were formed: [phenH][FeCl4], [methylphenH][FeCl4], [sec-butylphenH][FeCl4]. UV-vis spectroscopy was used to monitor the stability of the complex ions, and it was found that the sec-butylpheniron complex was more stable than the phen and methylphen analogues. This was based on the observation that free ligand was observed immediately upon the addition of EDTA to the [phenH][FeCl4] and [methylphenH] [FeCl4] complex ions.展开更多
The kinetics of the periodate oxidation of chromium(III)-complex, [CrIII(NTA)(Ala)(H2O)]-(NTA = Nitrilotriacetate and Ala = ß-alanine) to Cr(VI) have been carried out for the temperature range 15°C - 35&...The kinetics of the periodate oxidation of chromium(III)-complex, [CrIII(NTA)(Ala)(H2O)]-(NTA = Nitrilotriacetate and Ala = ß-alanine) to Cr(VI) have been carried out for the temperature range 15°C - 35°C under pseudo-first order conditions, >>?[complex]. Reaction obeyed first order dependence with respect to and [Cr(III)], and the rate of reaction increases with increasing of pH for the range 3.40 - 4.45. Experimentally, the mechanism of this reaction is found to be consistent with the rate law in which the hydroxo species, [CrIII(NTA)(Ala)(OH)]2- is considerably much more reactive than their conjugate acid. ΔH* and ΔS* have been calculated. It is proposed that electron transfer occurs through an inner-sphere mechanism via coordination of to chromium(III).展开更多
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 op...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.展开更多
Three new heterotrinuclear complexes have been synthesized and characterized, namely {[Gd(L)(2)](2)[Cu(pbaOH)]}(ClO4)(4), where pbaOH denotes 2-hydroxy-1,3-propylenebis(oxamato), L stands for 1,10-phenanthroline (phen...Three new heterotrinuclear complexes have been synthesized and characterized, namely {[Gd(L)(2)](2)[Cu(pbaOH)]}(ClO4)(4), where pbaOH denotes 2-hydroxy-1,3-propylenebis(oxamato), L stands for 1,10-phenanthroline (phen), 5-nitro-1,10-phenanthroline (NO2-phen) or 2,2'-bipyridyl (bpy). The temperature dependence of the magnetic susceptibility of ([Gd(phen)(2)(ClO4)](2)[Cu(pbaOH)])(ClO4)(2) has been studied in the 4-300K range, giving the exchange integral J = 6.69 cm(-1). This indicates a weak ferromagnetic interaction between the copper(II) and gadolinium(III) ions.展开更多
A new functionalized heteroleptic iridium complex coordinated with 1-phenylisoquinoline(1-piq) and a functionalized β-diketone(G1),Ir(1-piq)2G1,was synthesized and characterized by 1H-NMR,mass spectrometry and elemen...A new functionalized heteroleptic iridium complex coordinated with 1-phenylisoquinoline(1-piq) and a functionalized β-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 functionalized β-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
A comparative thermal decomposition kinetic investigation on Fe(III) complexes of a antipyrine Schiff base ligand, 1,2-Bis(imino-4’-antipyrinyl)ethane (GA)), with varying counter anions viz. CIO4-, NO3-, SCN-, Cl-, a...A comparative thermal decomposition kinetic investigation on Fe(III) complexes of a antipyrine Schiff base ligand, 1,2-Bis(imino-4’-antipyrinyl)ethane (GA)), with varying counter anions viz. CIO4-, NO3-, SCN-, Cl-, and Br-, has been done by thermogravimetric analysis by using Coats-Redfern equation. The kinetic parameters like activation energy (E), pre-exponential factor (A) and entropy of activation (ΔS) were quantified. On comparing the various kinetic parameters, lower activation energy was observed in second stage as compared to first thermal decomposition stage. The same trend has been observed for pre-exponential factor (A) and entropy of activation (ΔS). The present results show that the starting materials having higher activation energy (E), are more stable than the intermediate products, however;the intermediate products possess well-ordered chemical structure due to their highly negative entropy of activation (ΔS) values. The present investigation proves that the counter anions play an important role on the thermal decomposition kinetics of the complexes.展开更多
Spectrophotometric method was used to evaluate the kinetic of the complex formation from the reaction between H[Ru(III)Cl2(H2EDTA)] and the modifier agent [3-(2-aminoethyl)aminopropyl] trimethoxysilane (AEATS) (μ = 0...Spectrophotometric method was used to evaluate the kinetic of the complex formation from the reaction between H[Ru(III)Cl2(H2EDTA)] and the modifier agent [3-(2-aminoethyl)aminopropyl] trimethoxysilane (AEATS) (μ = 0.50 mol.dm-3 with NaCF3COO, 298.15 K), in pseudo-first order conditions. These studies showed that the reactions are successives producing several species influenced by the concentrations ratio. The electronics spectrum of all solutions showed a band in 457 nm with variable molar absorptivity (ε).展开更多
Objective We previously reported that mutations in inner mitochondrial membrane peptidase 2-like(Immp2l)increase infarct volume,enhance superoxide production,and suppress mitochondrial respiration after transient cere...Objective We previously reported that mutations in inner mitochondrial membrane peptidase 2-like(Immp2l)increase infarct volume,enhance superoxide production,and suppress mitochondrial respiration after transient cerebral focal ischemia and reperfusion injury.The present study investigated the impact of heterozygous Immp2l mutation on mitochondria function after ischemia and reperfusion injury in mice.Methods Mice were subjected to middle cerebral artery occlusion for 1 h followed by 0,1,5,and 24 h of reperfusion.The effects of Immp2l^(+/−)on mitochondrial membrane potential,mitochondrial respiratory complex III activity,caspase-3,and apoptosis-inducing factor(AIF)translocation were examined.Results Immp2l^(+/−)increased ischemic brain damage and the number of TUNEL-positive cells compared with wild-type mice.Immp2l^(+/−)led to mitochondrial damage,mitochondrial membrane potential depolarization,mitochondrial respiratory complex III activity suppression,caspase-3 activation,and AIF nuclear translocation.Conclusion The adverse impact of Immp2l^(+/−)on the brain after ischemia and reperfusion might be related to mitochondrial damage that involves depolarization of the mitochondrial membrane potential,inhibition of the mitochondrial respiratory complex III,and activation of mitochondria-mediated cell death pathways.These results suggest that patients with stroke carrying Immp2l^(+/−)might have worse and more severe infarcts,followed by a worse prognosis than those without Immp2l mutations.展开更多
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.
基金supported by the National Natural Science Foundation of China (No.20571033).
文摘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.
基金This work was supported by the National Natural Science Foundation of China(No.20272014)the Project of National Education Ministry(Project No.204097)National 973 Project of China(Project No.2002CB613400-5).
基金the NSFC (29973026, 29773017) and Beijing Natural Science Foundation (2992007) for the provision of financial support.
文摘The surface pressure-area (pi -A) isotherm of Schiff base aluminium (III), tris (2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium (III) (denoted as Al(TAl2)(3)), on pure water subphase was investigated. The molecular area, 0.48 nm(2), is one-third of expected value that indicated the aggregation took place. The Langmuir-Blodgett (LB) films of Al(TAl2), was transferred and characterized. The AFM image confirmed the formation of aggregates.
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Projects(20772101,50473046) supported by the National Natural Science Foundation of ChinaProject(2007FJ3017) supported by the Hunan Provincial Science Foundation, ChinaProject(07C764) supported by the Science Foundation of the Education Department of Hunan Province,China
文摘An iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C2][6-(6'-(4''-( 5'''-phenyl- 1''',3''',4'''-oxadiazole- 2 '''-yl) phenoxy) hexyloxy picolinate) was synthesized and characterized by 1H 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, C2](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.
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.
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.
基金Supported by the Natural Science Foundation of Guangdong Province,China(No.10152404801000017)
文摘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.
文摘Recent years,many novel complexes have been prepared by using hetero-bidentate ligands.However,complexes with such ligands as 4-vinylpyridine which has two different coordinating sites have not been reported,and only a few complexes of Cu(I)have been published^(1-3).The title complex Cu_2(C_5H_4N·CH=CH_2)_3Cl was prepared and characterized by elemental analyses,ICP,IR,and electronic spectra.Its conductivity,oxidation potential and reduction potential were measured.
文摘The synthesis is and crystal structure are reported for the sheet-like compourd [CU2(oxpn)Fe(CN )5(NO)]. there oxpn is the dianion of M, M'-bis(3-aminopropyl)oxamide. This compound crustallizes in the orthogonal space group Puma. with a=11 .413(4), b=22.242(5), c=7.736(2) A, and Z=4.The structure was refined to conventionat discrepancy factors R=0.047 and Pw=0.054. The Cu(II ) and Fe(III)centers are bridged by oxpn and cyanide, the formal behaves as a his-terdentate tigand bound to cooper(II)ion to form (II) dimers. whereas the latter bridges Cu(II) and Fe(III) centers in both symmetric and asymetric end- to-end bis-monodentate fashions, spreading out along be plane to form a 20 network. The Structure is made up of CuFe unit with Cu(II) and Fe(III) ions locating in a distorted square-based pyramid and a compressed octahedron, respectively.
文摘Vibrational and H-NMR spectroscopic studies on di-μ-chlorobis(1,5-cyclooctadiene) of iridium(I) and rhodium (I) complexes have been carried out. In addition, the two D2h and D2 structures for both complexes have been fully optimized. It was expected from the single-molecule vapor-phase density functional theory (DFT) calculation that the D2 structure is more stable by 5 - 6 kcal/mol. While spectroscopic analysis study confirms that in the solid phase, the two complexes retain the higher D2h symmetry. The vibrational wavenumbers of certain modes associated to free 1,5-cyc- looctadiene were observed to be shifted to lower values upon coordination with rhodium or iridium metals. It was also found theoretically that the metal-olefin interaction is slightly more pronounced for iridium metal.
文摘It has previously been demonstrated that phenanthroline-based ligands used to make gold metallotherapuetics have the ability to exhibit cytotoxicity when not coordinated to the metal center. In an effort to help assess the mechanism by which these ligands may cause tumor cell death, iron binding and removal experiments have been considered. The close linkage between cell proliferation and intracellular iron concentrations suggest that iron deprivation strategies may be a mechanism involved in inhibiting tumor cell growth. With the creation of iron (III) phen complexes, the iron binding abilities of three polypyridal ligands [1,10-phenanthroline (phen), 2,9-dimethyl-1, 10-phenanthroline (methylphen), and 2,9-di-sec-butyl-1, 10-phenanthroline (sec-butylphen)] can be tested via a competition reaction with a known iron chelator. Therefore, iron (III) complexes possessing all three ligands were synthesized. Initial mass spectrometric and infrared absorption data indicate that iron (III) tetrachloride complex ions with protonated phen ligands (RphenH+) were formed: [phenH][FeCl4], [methylphenH][FeCl4], [sec-butylphenH][FeCl4]. UV-vis spectroscopy was used to monitor the stability of the complex ions, and it was found that the sec-butylpheniron complex was more stable than the phen and methylphen analogues. This was based on the observation that free ligand was observed immediately upon the addition of EDTA to the [phenH][FeCl4] and [methylphenH] [FeCl4] complex ions.
文摘The kinetics of the periodate oxidation of chromium(III)-complex, [CrIII(NTA)(Ala)(H2O)]-(NTA = Nitrilotriacetate and Ala = ß-alanine) to Cr(VI) have been carried out for the temperature range 15°C - 35°C under pseudo-first order conditions, >>?[complex]. Reaction obeyed first order dependence with respect to and [Cr(III)], and the rate of reaction increases with increasing of pH for the range 3.40 - 4.45. Experimentally, the mechanism of this reaction is found to be consistent with the rate law in which the hydroxo species, [CrIII(NTA)(Ala)(OH)]2- is considerably much more reactive than their conjugate acid. ΔH* and ΔS* have been calculated. It is proposed that electron transfer occurs through an inner-sphere mechanism via coordination of to chromium(III).
文摘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.
文摘Three new heterotrinuclear complexes have been synthesized and characterized, namely {[Gd(L)(2)](2)[Cu(pbaOH)]}(ClO4)(4), where pbaOH denotes 2-hydroxy-1,3-propylenebis(oxamato), L stands for 1,10-phenanthroline (phen), 5-nitro-1,10-phenanthroline (NO2-phen) or 2,2'-bipyridyl (bpy). The temperature dependence of the magnetic susceptibility of ([Gd(phen)(2)(ClO4)](2)[Cu(pbaOH)])(ClO4)(2) has been studied in the 4-300K range, giving the exchange integral J = 6.69 cm(-1). This indicates a weak ferromagnetic interaction between the copper(II) and gadolinium(III) ions.
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 β-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 functionalized β-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A comparative thermal decomposition kinetic investigation on Fe(III) complexes of a antipyrine Schiff base ligand, 1,2-Bis(imino-4’-antipyrinyl)ethane (GA)), with varying counter anions viz. CIO4-, NO3-, SCN-, Cl-, and Br-, has been done by thermogravimetric analysis by using Coats-Redfern equation. The kinetic parameters like activation energy (E), pre-exponential factor (A) and entropy of activation (ΔS) were quantified. On comparing the various kinetic parameters, lower activation energy was observed in second stage as compared to first thermal decomposition stage. The same trend has been observed for pre-exponential factor (A) and entropy of activation (ΔS). The present results show that the starting materials having higher activation energy (E), are more stable than the intermediate products, however;the intermediate products possess well-ordered chemical structure due to their highly negative entropy of activation (ΔS) values. The present investigation proves that the counter anions play an important role on the thermal decomposition kinetics of the complexes.
文摘Spectrophotometric method was used to evaluate the kinetic of the complex formation from the reaction between H[Ru(III)Cl2(H2EDTA)] and the modifier agent [3-(2-aminoethyl)aminopropyl] trimethoxysilane (AEATS) (μ = 0.50 mol.dm-3 with NaCF3COO, 298.15 K), in pseudo-first order conditions. These studies showed that the reactions are successives producing several species influenced by the concentrations ratio. The electronics spectrum of all solutions showed a band in 457 nm with variable molar absorptivity (ε).
基金This study was supported by the National Natural Science Foundation of China(Nos.81360196,81760240the Natural Science Foundation of Ningxia(No.2022AAC03159)the Ningxia Innovation Team of the Foundation and Clinical Research of Diabetes and Its Complications(No.NXKJT2019010).
文摘Objective We previously reported that mutations in inner mitochondrial membrane peptidase 2-like(Immp2l)increase infarct volume,enhance superoxide production,and suppress mitochondrial respiration after transient cerebral focal ischemia and reperfusion injury.The present study investigated the impact of heterozygous Immp2l mutation on mitochondria function after ischemia and reperfusion injury in mice.Methods Mice were subjected to middle cerebral artery occlusion for 1 h followed by 0,1,5,and 24 h of reperfusion.The effects of Immp2l^(+/−)on mitochondrial membrane potential,mitochondrial respiratory complex III activity,caspase-3,and apoptosis-inducing factor(AIF)translocation were examined.Results Immp2l^(+/−)increased ischemic brain damage and the number of TUNEL-positive cells compared with wild-type mice.Immp2l^(+/−)led to mitochondrial damage,mitochondrial membrane potential depolarization,mitochondrial respiratory complex III activity suppression,caspase-3 activation,and AIF nuclear translocation.Conclusion The adverse impact of Immp2l^(+/−)on the brain after ischemia and reperfusion might be related to mitochondrial damage that involves depolarization of the mitochondrial membrane potential,inhibition of the mitochondrial respiratory complex III,and activation of mitochondria-mediated cell death pathways.These results suggest that patients with stroke carrying Immp2l^(+/−)might have worse and more severe infarcts,followed by a worse prognosis than those without Immp2l mutations.