高效白色磷光有机电致发光器件

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indiumtin 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-hydroxy quinoline 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3 V启亮, 在16.5 V时, 器件的最高亮度达到15460 cd·m^-2; 在4 V时, 器件达到最大流明效率为7.5 lm·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8 V后Commission Internationale I’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.     

Instability Origin and Improvement Scheme of Facial Alq3 for Blue OLED Application

Degradation phenomenon and poor stability of tris(8-hydroxyquinoline) aluminum(III)(Alq₃)-based organic light-emitting diodes(OLEDs) have attracted much attention. In this paper, we discussed the origin of instability of the facial Alq₃-based blue luminescent OLEDs with the help of first-principles calculation. The results show that environmental humidity seriously affects the luminescence stability of Alq₃-based OLEDs. H₂O molecules in environment can be firmly bound to the oxygen atoms of the facial Alq₃, which then act as starting points for further degradation of Alq₃. Moreover, the interactions between facial Alq₃ and different cathode metal layers were investigated to explain the experiment phenomenon. A design guideline for diminishing the strong attraction from oxygen atoms can be proposed to protect Alq₃ and improve the stability of materials applied in OLEDs.     

波浪形一维链状镉配合物的合成、结构及分子识别性能

以四水合硝酸镉(Cd(NO_3)_2·4H_2O)与2-(邻溴)苯基-4,5-咪唑二羧酸(o-BrPhH_3IDC)和草酸铵通过水热反应,合成了一个波浪形一维链状配合物{[Cd(o-BrPhH_2IDC)_2(H_2O)]·H_2O}_n(1)。并通过元素分析、傅里叶变换红外光谱、热重分析和单晶X射线衍射等技术手段对配合物1进行了表征。结果表明,配合物1为正交晶系,Pbca空间群。配合物1在316 nm波长激发下,在356 nm处有最大的荧光发射峰。配合物1对小分子具有识别性能,乙腈使配合物荧光强度明显增强,甲醇、乙醇使配合物荧光强度明显减弱,而吡啶处理后的样品在356 nm附近的发射峰消失,显示对吡啶有识别作用。     

Syntheses, crystal structures and characterizations of new zinc (II) and lead (II) carboxylate-phosphonates

The syntheses, crystal structures and characterizations of two new divalent metal carboxylate-phosphonates, namely, Zn(H₃L)·2H₂O (1) and Pb(H₃L)(H₂O)₂ (2) (H₅L4-HO₂C–C₆H₄–CH₂N(CH₂PO₃H₂)₂₎ have been reported. Compound 1 features a 1D column structure in which the Zn(II) ions are tetrahedrally coordinated by four phosphonate oxygen atoms from four phosphonate ligands, and neighboring such 1D building blocks are further interconnected via hydrogen bonds into a 3D network. The carboxylate group of H₃L anion remains non-coordinated. Compound 2 has a 2D layer structure. Pb(II) ion is 7-coordinated by four phosphonate oxygen atoms from four phosphonate ligands and three aqua ligands. The interconnection of Pb(II) ions via bridging H₃L anions results in a 001 layer. The carboxylate group of the H₃L anion also remains non-coordinated and is oriented toward the interlayer space. Solid state luminescent spectrum of compound 1 exhibits a strong broad blue fluorescent emission band at 455 nm under excitation at 365 nm at room temperature.     

咪唑二羧酸构筑的铕配合物的合成、晶体结构及发光性能

2-(邻溴)苯基-4,5-咪唑二羧酸(o-BrPhH₃IDC)与六水合硝酸铕(Eu(NO₃)₃·6H₂O)在对苯二甲酸存在下,在乙睛和水的混合溶剂中,通过溶剂热反应,合成了一个三维超分子配合物(H₃O)[Eu(o-BrPhH₂IDC)₄](1)。 采用单晶X射线衍射对配合物1的晶体结构进行了测试,结果表明,配合物1为立方晶系,I-43d空间群;中心铕离子处于一个八配位的体系中。 对配合物1的固态荧光研究发现:在395 nm的激发波长下,标题配合物显示出特征的铕发射光谱。 这说明所采用的有机配体具有良好的天线效应,对铕离子有很好的敏化效应。     

双核锌配合物[Zn(dna)(phen)(H_2O)]的合成、结构及性质

以5,5'-二硫代双(2-硝基苯甲酸)(H2dna)和1,10-邻菲啰啉(phen)为配体在水热条件下合成了标题配合物,并利用元素分析、傅里叶变换红外光谱、X射线单晶衍射、X射线粉末衍射以及热重分析等技术手段对该配合物进行了结构和性质表征。晶体结构分析表明:配合物为单斜晶系,P2_1/n空间群,a=1.5312(3)nm,b=1.16054(18)nm,c=1.5609(3)nm,β=110.451(2)°,V=2.5990(7)nm~3,Z=4。该配合物为环状双核结构。基于氢键作用邻近的双核分子相连形成一维超分子链。而邻近超分子链又基于S幆O和CH幆π的弱相互作用扩展形成三维超分子网结构。该配合物失水后的产物保持相对稳定,直到245~450℃配体才开始分解,表现出良好的热稳定性。配合物在波长为280 nm的光源激发下,在440 nm有较强的荧光发射峰,且发射峰的形状与H2dna配体相似,但配合物的荧光强度相比H2dna配体有了明显的增强。     

不同掺杂浓度Tm3+：LiLuF4单晶的1800 nm荧光发射

采用坩埚下降法生长了Tm3+掺杂浓度为0.45%,0.90%,1.63%与3.25%(摩尔分数,x)的LiLuF4单晶.测试了样品的电感耦合等离子体原子发射光谱(ICP-AES)、X射线衍射(XRD)谱、吸收光谱(1400-2000 nm),并且分析比较了808 nm半导体激光器(LD)激发下荧光光谱.结果表明:当Tm3+的浓度从0.45%变化到3.25%时,1800 nm处的荧光强度呈现了先增后减的趋势,当掺杂浓度约为0.90%时达到最大值,而位于1470 nm处的荧光强度则呈现了相反的趋势.Tm3+:3F4能级的荧光衰减寿命随着掺杂浓度的增加不断减小.1800 nm处的这种荧光强度变化归结于Tm3+离子间的交叉驰豫效应(3H6,3H4→3F4,3F4)和自身的浓度猝灭效应.同时计算得到了浓度为0.90%的样品在1890 nm处的最大发射截面为0.392×10-20cm2.并且根据Judd-Ofelt理论所得寿命和测定的荧光寿命计算得到了3F4→3H6的最大量子效率约为120%.     

Gold and Silver Nanoparticles Supported on Metal-organic Frameworks: a Highly Active Catalyst for Three-component Coupling Reaction

Engineering metal-organic frameworks(MOF) for heterogeneous catalysts have been of extreme interest since they have large pore size within the crystalline framework and well defined pore architecture. Ni-containing MOF Ni₂(3,5-Pydc)₂(H₂O)₈·2H₂O(1·H₂O) was prepared by solvothermal method from 3,5-pyridinedicarboxylic acid, D-camphoric acid and Ni(NO₃)₂·6H₂O in dimethylformamide(DMF)/water(volume ratio 2:1). And two gold and silver functionalized 1·H₂O catalysts were prepared by impregnation method. Catalysts 2.53%Au/MOF and 4.23%Ag/MOF were in-depth characterized by single crystal X-ray diffraction, powder X-ray diffraction(PXRD), thermogravimetric analysis(TGA), transmission electron microscopy(TEM), and inductively coupled plasma-atomic emission spectroscopy(ICP-AES). Their catalytic performance was examined in one-pot synthesis of structurally divergent propargylamines via three component coupling of aldehyde, alkyne, and amine(A³) in 1,4-dioxane. The results show that the catalysts all displayed high reactivities, and a selectivity of 100% for propargylamines. Catalysts 2.53%Au/MOF and 4.23%Ag/MOF have proved to be applicable to a wide range of substrates. Catalysts 2.53%Au/MOF and 4.23%Ag/MOF can be easily recycled and used repetitively at least 3 times with a slight drop in activity. These features render the catalysts particularly attractive in the practice of propargylamines synthesis in an environmentally friendly manner.     

新型掺杂多孔芳香骨架材料的储氢性能模拟

基于PAF-301分子模型通过Li掺杂或B取代等模式设计了几种新型多孔芳香骨架(PAFs)材料,采用量子力学和分子力学方法对新材料的储氢性能进行研究.由量子力学计算得到了不同分子片段与H2之间的结合能,并结合DDEC方法计算了各分子片段的原子电荷分布.利用巨正则蒙特卡洛(GCMC)模拟方法计算了77和298 K下H2在不同PAFs材料中的吸附平衡性质.结果表明,H2直接与苯环的结合能较低,但掺杂Li原子能够提高H2与六元环的结合能,同时Li原子体现出较高的正电性质,B原子取代苯环中的两个C原子后,使得原有C原子电负性增强;77 K下PAF-301Li具有最高的储氢性能,而PAF-C4B2H4-Li2-Si和PAF-C4B2H4-Li2-Ge体现出较好的常温储氢性能,各种材料的常温储氢性能远低于其低温储氢性能.通过77 K下H2在PAFs材料中的等位能面分布和吸附平衡质心密度分布对H2在PAFs材料中的优先吸附位置进行分析,发现在PAF-301和PAF-301Li骨架中,由于中心能量较低的等位能区域范围较宽,H2在其中存在四个明显的吸附高密度分布区域,而其它三种PAFs晶胞中心能量较低的等位能区域范围较窄,使得H2在其中只存在两个明显的吸附高密度分布区域.     

Co(Ⅱ)-Zn(Ⅱ)掺杂配位聚合物的 合成及物理性能

采用均苯三甲酸配体、 硝酸锌与硝酸钴反应, 一步合成了钴掺杂的锌配位聚合物Zn_1-xCo_x(BTC)·(OH)(H₂O)₃(NMP)(DMF)(H₂O)_1.5(H₃BTC为1,3,5-均苯三酸, NMP为1-甲基-2-吡咯烷酮, DMF为N,N'-二甲基甲酰胺, x=0~0.8). 该化合物结构经X射线单晶衍射确定, 属于立方晶系, 空间群P2₁3, 晶胞参数a=1.43863(20) nm. 利用元素分析、 能量散色光谱(EDS)、 UV-Vis光谱、 X射线粉末衍射(XRD)、 热重分析(TGA)、 氮气吸附和磁性分析等表征手段对样品的物理性质进行了表征. 氮气吸附实验结果表明, 该配位聚合物具有良好的微孔吸附特性, Langmiur比面积为832 m ²/g, 孔径为0.84 nm; 元素分析结果表明, 钴/锌摩尔比为1∶1时, 在37~300 K温度范围内其磁性表现为反铁磁性, 并满足Curie-Weiss定律.     

Spectrophotometric determination of hydrogen peroxide in rainwater

Hydrogen peroxide in rainwater has been determined from the measurement of absorption at 432 nm after the formation of the stable oxo-peroxo-pyridine-2,6-dicarboxylatovanadate(V) complex (OPDV) in acid media. Determinations were in good agreement with those using a modified p-hydroxyphenylacetic acid (PHPA) emission method. The linear range for the OPDV method is from 0.05 to 50 ppm H₂O₂, and the limit of detection under the analytical conditions employed was 5.8 nmol H₂O₂ for a 20 cm³ rainwater sample. The volume weighted mean H₂O₂ concentration in rainwater collected at roof-top level in central Kowloon was 15.9 μM (N=10), and the ratio of non-sea salt sulphate and H₂O₂ concentrations was significantly correlated with pH. The OPDV absorption method was also employed for the determination of ambient gaseous H₂O₂, and liquid-nitrogen cold-trap collection gave results about 30% lower than impinger sampling, where artifact H₂O₂ formation occurred.     

Structure,Thermal Behavior and Characterization of a New Hybrid Iron Fluoride FeF4(2,2'-bipyridine)(H2O)2

New crystal of FeF₄(2,2'-bipyridine)(H₂O)₂ was prepared by hydrothermal synthesis. Crystalline structure determination is performed from single crystal X-ray diffraction data. The unit cell is monoclinic space group P2₁/n, with cell parameters a=0.9046(5) nm, b=0.7502(5) nm, c=1.9539(5) nm, β=93.307(5)°, V=1.3238(12) nm³ and Z=4. The structure of FeF₄(2,2'-bipyridine)(H₂O)₂ is built up from FeF₄N₂ octahedra coordinated by two nitrogen atoms of the 2,2'-bipyridine molecules, and four fluorine atoms as well as uncoordinated H₂O molecules. Thermal analysis of the title compound showed that the decomposition introduced four steps. IR spectra confirmed the presence of 2,2'-bipyridine molecules. The optical absorption was measured at the corresponding l_max using UV-Vis diffuse reflectance spectrum.     

Polycyclic aromatic hydrocarbon-bridged coumarin derivatives for organic light-emitting devices

Three biscoumarin dyes bridged by polycyclic aromatic bridges (anthracen, pyrene and dibenzo[g,p]chrysene) were prepared as the emissive materials for the application of organic light-emitting devices. The relationship between their structures, photophysical properties, electrochemical properties and performances of organic light-emitting devices are described. The multilayered doped devices with a configuration of ITO/NPB (20 nm)/TBADN: biscoumarin compound (x wt%, 30 nm)/TPBi (30 nm)/Liq (2 nm)/Al (100 nm) have been successfully fabricated by vacuum-deposition method. All the devices showed green emission with high electroluminescent efficiencies. Especially, the device based on the compound containing pyrene as a bridge group at 7% doping concentration showed the best performance with a maximum brightness of 10552 cd/m², maximum luminous efficiency of 5.39 cd/A and maximum external quantum efficiency (EQE) of 2.35%.     

新的四帽Keggin结构的金属-氧簇合物[NiMo12O40H10{Ni(H2O)3}4]的水热合成与结构表征

多金属氧酸盐 (也称金属 -氧簇 )由于在催化、材料及医药等领域的应用日益广泛而备受关注 .近年来 ,一些新颖的非经典结构的化合物不断被合成出来 .如带二帽的 Keggin结构化合物 [V15O4 2 ]9- [1] ,[PV14 O4 2 ]9- [2 ] ,[As V14 O4 2 ]9- [3 ] ,[{ Mo8V7O4 2 } 2 ]14 - [4 ] ,     

The luminescent properties of divalent europium complexes of crown ethers and cryptands

The luminescent properties of divalent europium complexes with crown ether, azacrown ether, N-pivot-azacrown ether, and cryptand in methanol or water have been systematically investigated under UV irradiation. These divalent europium complexes show greatly enhanced emission from 417 nm to 488 nm in the visible blue region in comparison with that of the methanol solution of EuCl₂. The aqueous solution of EuCl₂ is non-luminescent. This obvious distinction in luminescent properties between the macrocyclic ligand-coordinated divalent europium and uncoordinated divalent europium is attributed to the “insulation effect” of Eu²⁺ ion from the solvent molecules of CH₃OH and H₂O by the macrocyclic crown ether or cryptand encapsulation to divalent europium. Moreover, these macrocyclic ligands provide an additional restriction to the electronic charge expansion of the excited Eu²⁺. This also contributes to the enhancement of the Eu²⁺ luminescence. Among all the investigated macrocyclic ligands, 15-crown-5 (15C5) affords the largest enhancement to the Eu²⁺ emission. The intensity of the Eu²⁺–15C5 complex is 690 times that of the EuCl₂ methanol solution with the same Eu²⁺ concentration. This special emission enhancement effect is related to the particular complex composition of 1:3 (Eu²⁺:15C5) and corresponding configuration of Eu²⁺–15C5 complex in methanol. Concerning the mechanism, the luminescence enhancement of divalent europium by complexation with these macrocyclic crown ether or cryptand ligands is found to be initiated from the decrease in non-radiative rate constant rather than from the increase in radiative one.

The divalent europium complexes of methacrylate polymeric polyether derivatives such as 15C5-, 18-crown-6- (18C6), and cryptand [2.2.1]- or [2.2.2]-containing polymer and copolymer have also been prepared. Their luminescent properties in solid state have been studied to aim for practical application. As a similar situation to the simple polyether complexes, the divalent europium complex with 15C5-containing polymer or copolymer shows the largest luminescent enhancement effect. Its emission intensity reaches about 20% that of the commercial inorganic luminescence product CaWO₄:Pb (NBS 1026). In addition, the doping effect of several divalent ions, namely Mg, Sr, Ba and Zn in polymeric complexes, has also been investigated according to the luminescence concentration quenching mechanism in solid state luminescence materials. The emission intensity of 15C5-containing polymer europium(II) complex is raised to twice stronger by doping of Zn²⁺ ion.     

一种新型磷酸钛大单晶的溶剂热法合成与结构研究

用水热或溶剂热法合成具有一维链状、二维层状及三维微孔结构的新型磷酸盐ＭｅＰＯ4(Ｍｅ =Ａｌ,Ｆｅ,Ｚｎ ,Ｚｒ等 )晶体目前已成为国内外研究的热点[15 ],这主要是由于磷酸盐结构的多样性以及它们在吸附、分离、催化、光学等方面的良好应用[6 ,7].磷酸钛类化合物作为一类具有良好非线性光学特性及氧化催化性能的功能材料 ,正日益受到人们的重视 ,而获得磷酸钛优质大单晶也是研究热点之一 .这类化合物通常易于得到微晶粉末而难于获得大晶体 ,由于缺少单晶结构数据 ,对具有新型结构磷酸钛的研究目前受到一定限制[8,9],尤其是以有机物为模板…     

抗菌医药左氧氟沙星在有机电致发光二极管中的应用

左氧氟沙星(LOFX)是一种知名的抗菌药物, 它的价格非常便宜, 且有成熟的合成和纯化技术. 本文中首次将LOFX作为一种蓝光发光材料和电子传输材料应用于有机电致发光器件(OLED)中. 通过热重分析、UVVis吸收光谱、发射光谱以及循环伏安曲线详细地表征了LOFX的热学及光物理特性. LOFX有高的分解温度,为327 ℃; HOMO、LUMO能级分别为-6.2 和-3.2 eV, 光学带隙为3.0 eV. 以LOFX作为客体材料, 掺杂在主体材料4,4'-二(9-咔唑)联苯(CBP)中制备了蓝光OLED, 该器件的电致发光(EL)发射峰位于452 nm, 最大亮度为2315 cd·m^-2. 进一步, 选择8-羟基喹啉铝(Alq₃)作为参考材料, 分别以LOFX和Alq₃作为电子传输材料制备了结构相同的单载流子器件和绿色磷光OLED. 在相同的电压下, 以LOFX作为电子传输材料的单载流子器件的电流密度比以Alq₃作为电子传输材料的单载流子器件更高. 同时, 以LOFX作为电子传输材料的绿色磷光OLED获得更高的器件效率. 从这些EL性能可以看出, LOFX同时也是一很好的电子传输材料.     

Mn(II)配合物的晶体结构及表面光电性能

采用水热法合成3个新的Mn(II)配合物[Mn(SO₄)(H₂O)₃]_n (1), [Mn2.5(HPO₄)(PO₄)(H₂O)₂]_n (2), [Mn(phen)₂(H₂O)₂]·(C₄H₄O₄)·4H₂O (3) (phen=1,10-邻二氮杂菲). 用X射线单晶衍射、表面光电压光谱(SPS)、红外光谱(IR)、紫外-可见吸收光谱(UV-Vis)、电子顺磁共振谱(EPR)对配合物进行了表征. 结构解析表明: 配合物1是具有2D结构的配合物, 氢键将其连接成3D超分子; 配合物2是具有3D无限结构的配合物; 配合物3是单核配合物, 再由多种氢键连接, 形成3D超分子. SPS结果表明, 3个配合物在300-800 nm范围内都呈现明显的光伏响应, 表明它们均具有一定的光-电转换性能. 讨论了配合物结构, 空间维度和中心金属离子配位环境的不同对配合物表面光电性能的影响以及SPS与UV-Vis的关联: 配合物的结构维度越高、规则性越好, SPS响应强度越大; 中心金属离子的直接配位原子种类的不同、所处外晶场的强弱不同, SPS响应带的数目和位置明显不同.     

Spectrophotometric determination of H(2)O(2) in marine waters with leuco crystal violet

H₂O₂ in marine waters may be determined by measuring the absorbance of crystal violet (CV⁺), formed by the oxidation of leuco crystal violet (LCV) by H₂O₂ in the presence of the enzyme horseradish peroxidase, at 592 nm at pH 4. The detection limit and the precision of the method are about 0.02 μM and ± 1% (at a concentration of 0.03 μM), respectively. The results obtained by this method and by a widely used fluorimetric method agreed with each other well. After color development, samples together with the sub-samples for constructing the calibration curve may be stored for up to 5 days before their absorbances are measured without significantly changing the estimated concentration of H₂O₂.     

Nature of the red emission in the chemical oxygen iodine laser system

Intense red emission peaking at 703 nm is observed when a heated metal wire is placed downstream of an O₂(¹Δ_g) generator used in the chemical oxygen iodine laser (COIL) system. The O₂(¹Δ_g) is produced by bubbling Cl₂ through an alkaline solution of H₂O₂. Evidence is presented that strong red emission requires the presence of both O₂(¹Δ_g) and Cl₂ in contact with a heated metal surface. Several metals have been used. The red emission spectrum is independent of the metal and the intensity is strongest for copper.