基于蒽/芘分子封端的芴-芳胺衍生物的可溶液加工的蓝光材料的合成与光电性质（英文）

合成了两类分别基于芘和蒽封端的芴-芳胺衍生物(FAn,FPy)的新型可溶液加工蓝色发光分子,两种材料均溶于常规的有机溶剂,并且可以旋涂成膜.通过紫外-可见光谱和荧光光谱对其在溶液中和固态薄膜下的光学性能进行了表征,发现这两类分子在固态下发射峰分别位于449和465 nm,属于蓝色发光材料.并通过循环伏安法表征了其电化学性能,计算得出FAn和FPy的最高占据分子轨道(HOMO)能级分别为-5.37和-5.36eV.结果表明N-己基二苯胺的引入有效阻止了分子在固态下的平面堆积,抑制了长波发射,并且提高了分子HOMO能级,改善了空穴注入能力.差示扫描量热法(DSC)和热重分析(TGA)测试表明这两类化合物均显示出良好的热稳定性,其中FAn的玻璃化转变温度和热分解温度分别达到了207和439℃.良好的性能使得这两类材料成为一种潜在的可溶液加工的蓝光材料.     

一种电致发光有机化合物的合成及其发光性能的检验

制备了有机电致发光材料1，3-二[（4′-特丁基苯基）-（1″，3″-噁二唑-5）]-苯（以下简写作OXD-7），通过核磁共振光谱、红外光谱对其结构进行了表征。利用紫外可见吸收光谱、荧光光谱和循环伏安法等研究了其最高被占用分子轨道（HOMO）及最低空余分子轨道（LUMO）能级及发光性能。OXD-7的HOMO能级为5．24eV，LUMO能级为1．69eV。OXD-7在306nm波长处有一吸收峰。采用300nm的紫外光激发，荧光发射峰值波长为366．6nm。     

螺二芴基可溶性共聚物的合成及发光性能

以9,9'-螺二芴和不同链长的二烷氧基苯为单体, 以FeCl3为催化剂, 采用化学氧化法合成了一系列聚合物发光材料. 溶解度测试表明, 共聚物在二氯甲烷、四氢呋喃(THF)、氯仿等极性溶剂中具有良好的溶解性. 利用核磁共振氢谱(1H NMR)、傅里叶变换红外(FT-IR)光谱、紫外-可见(UV-Vis)光谱和荧光(PL)光谱研究了共聚物的化学结构和发光性能, 结果表明共聚物在二甲基亚砜(DMSO)中均发射蓝色荧光, 最大吸收和荧光发射峰分别为356和413 nm. 以硫酸奎宁溶液作为参比, 测得共聚物的荧光量子效率为0.69至0.77. 通过循环伏安法(CV)测得所合成的三种共聚物的最高占有分子轨道(HOMO)能级均位于-5.85至-5.69 eV之间.     

2-(2-苯并咪唑)-6-甲基吡啶锌配合物的合成及发光性质

合成了2-(2-苯并咪唑)-6-甲基吡啶及其锌配合物,通过元素分析、摩尔电导率、红外光谱和紫外光谱对产物进行了表征,并运用荧光光谱对配合物的发光性质进行了研究。结果表明,锌配合物在DMF溶液中的荧光最大发射波长为428nm,在固态下的荧光最大发射波长为448nm,均属于蓝光发射,具有作为蓝色发光材料的潜能。     

三嗪类双极性蓝色磷光主体材料的合成及性能

设计合成了一种基于三嗪类的新型双极性蓝色磷光主体材料9-[4-(4,6-二-α-萘氧基-1,3,5-三嗪-2-基)苯基]咔唑(NOTPC),并对其结构进行了表征。通过紫外-可见(UV-Vis)吸收、荧光、低温磷光、循环伏安法、热重分析(TGA)、差热分析(DSC)和密度泛函理论(DFT)对其性能及结构进行了研究。结果表明,NOTPC在CH2Cl2稀溶液中的吸收峰位于341和374nm;发射峰位于478nm;NOTPC的低温(77K)磷光光谱的第一发射峰位于442nm,其三线态能级为2.80eV,与蓝色磷光材料FIrpic(2.62eV)的能级相匹配;NOTPC的HOMO主要分布在苯基咔唑单元,而LUMO主要定域在三嗪环上。其HOMO能级为-5.40eV,与阳极ITO的功函(-4.5~-5.0eV)相匹配,LUMO能级为-2.32eV,接近于电子传输材料PBD(-2.82eV),NOTPC表现出双极传导性能,且热稳定性良好。     

新型可溶性酞菁的合成和光致发光及电致发光性质

以3(4)-硝基邻苯二腈和对甲氧基苯酚为原料, 经过两步反应合成了α(β)-四(4-甲氧基苯氧基)酞菁锌, 通过谱学方法和元素分析表征了其结构. 比较研究其溶液和旋涂膜的紫外可见光谱、光致发光光谱和固体薄片的光致发光光谱. 并以其旋涂膜为发光层制备了电致发光器件, 研究其电致发光性质. 结果表明, 固态酞菁材料与其溶液的荧光发射波长相比均向长波方向移动了145 nm以上, 而且都有不同程度的宽展. 在固态下β-位取代酞菁荧光发射波长红移的程度比α-位取代酞菁大. 电致发光光谱的发射波长和其旋涂膜的光致发光光谱的发射波长基本一致, 大约在856和862 nm左右. 在固态下酞菁分子排列紧密, 分子间相互作用增强导致了荧光发射波长的巨大红移.     

咔唑并噻唑类蓝色荧光材料的合成及电致发光性质

以钯为催化剂,通过C—C和C—N偶联反应分别合成了两种咔唑并噻唑类蓝色荧光材料:TCz-PCz和TCz-TPA,并采用质谱、~1H NMR、~(13)C NMR和元素分析等对其结构进行了鉴定.系统地研究了这些材料的热稳定性、光物理性质和电化学行为,结果表明这些化合物具有良好的热稳定性和形态稳定性,热分解温度高达400℃,玻璃化转变温度为119℃.在溶液中,这两种材料均发射出强的蓝光,荧光量子效率分别为71%和73%;这些分子的HOMO能级分别为-5.41和-5.21 eV,较高的HOMO能级有利于器件中空穴从空穴传输层向发光层的注入和传输.以TCz-PCz为发光材料,通过真空蒸镀技术制备了非掺杂型有机电致发光器件,研究了其电致发光性能.结果显示该器件具有稳定的蓝光发射,启亮电压仅为3.1 V,最大发光亮度和电流效率分别为2190 cd·m~(-2)和2.88 cd·A~(-1).     

一种苯并咪唑类双极性蓝色磷光主体材料的合成及性能

设计合成了一种基于苯并咪唑的新型双极性蓝色磷光主体材料1-苯基-2-[4-(N-咔唑基)苯基]苯并咪唑(PCPB),并对其结构进行了表征。通过紫外-可见、荧光、低温磷光光谱以及循环伏安法、热重分析、差热分析和密度泛函理论对其性能及结构进行了研究。结果表明,PCPB在CH2Cl2稀溶液中的吸收峰位于296和368 nm,发射峰位于401nm,属于深蓝色荧光;PCPB的低温(77K)磷光光谱的第一吸收峰位于452nm,其三线态能级为2.74e V,与蓝色磷光材料FIrpic(2.62e V)的能级相匹配;PCPB的HOMO主要分布在苯基咔唑单元,而LUMO主要定域在苯并咪唑环上。其HOMO能级为-5.54e V,与阳极ITO的功函(-4.5~-5.0 e V)相匹配,LUMO能级为-2.68e V,接近于电子传输材料PBD(-2.82e V)。PCPB表现出双极传导性能,且热稳定性良好。     

含咔唑衍生物的聚硅氧烷发光材料的合成及其性能

设计并合成了含咔唑衍生物的聚硅氧烷发光材料。通过核磁共振、元素分析、紫外-可见吸收光谱、荧光光谱、热失重分析、循环伏安法对其结构和性能进行了表征。结果表明:该化合物具有良好的荧光性能和热稳定性,其发射波长为408 nm,分解温度在242℃,最高占据分子轨道能级和分子最低空轨道能级分别为4.70 eV和1.16 eV。     

聚集诱导发光新材料9,10-双[2-(1-甲基-1H-吡咯-2-基)乙烯基]蒽的 合成及性能

合成并全面表征了一种新的蒽烯类化合物9,10-双[2-(1-甲基-1H-吡咯-2-基)乙烯基]蒽(MPVAn). 该化合物具有显著的聚集诱导发光特性. 它在溶液态时几乎不发光, 但在固态时的光致发光强度达到溶液态的数百倍. 为了确定标题化合物的聚集诱导发光机制, 研究了它在不同溶液粘度及温度下的光致发光行为, 结果表明聚集态发光增强是由于分子内转动受阻所致. 它的粉末在420 nm光的激发下发射纯的黄光, 峰值为562 nm, 半峰宽为66 nm. 采用紫外-可见吸收光谱及循环伏安法研究了化合物的电子性能, 其HOMO和LUMO能级分别为－4.78和－2.28 eV.     

基于蒽/芘分子封端的芴-芳胺衍生物的可溶液加工的蓝光材料的合成与光电性质

Two novel potential solution-processed blue fluorescent emitters composed of a core fluorenediphenylamine unit capped with either anthracene (FAn) or pyrene (FPy) were synthesized and characterized. They were both soluble in common organic solvents and solutions gave smooth films after spin coating. Their optical properties in solution and in the film were investigated by UV-visible and photoluminescence (PL) spectroscopy. The PL emission maximum of FAn and FPy in the film state were found to be 449 and 465 nm, respectively. The electrochemical properties of the as-prepared samples were studied by cyclic voltammetry. The estimated highest occupied molecular orbital (HOMO) energy levels were -5.37 and -5.36 eV for FAn and FPy, respectively. These results indicate that the introduction of diphenylamine effectively prevents plane stacking of the molecules in the solid state, which suppresses the formation of long-wavelength aggregates, and the high HOMO levels enhance the hole-injection ability of the compounds. The results of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) indicate that the two materials have excellent thermal stability with the glass transition temperature of FAn reaching 207 ℃ and the thermal decomposition temperature as high as 439 ℃. The good performance of the fluorescent emitters makes them promising candidates as solution-processed blue organic light-emitting diodes.     

Carbazole-Decorated Organoboron Emitters with Low-Lying HOMO Levels for Solution-Processed Narrowband Blue Hyperfluorescence OLED Devices

The hyperfluorescence has drawn great attention in achieving efficient narrowband emitting devices based on multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters. However, achieving efficient solution-processed pure blue hyperfluorescence devices is still a challenge, due to the unbalanced charge transport and serious exciton quenching caused by that the holes are easily trapped on the high-lying HOMO (the highest occupied molecular orbital) level of traditional diphenylamine-decorated emitters. Here, we developed two narrowband blue organoboron emitters with low-lying HOMO levels by decorating the MR-TADF core with weakly electron-donating carbazoles, which could suppress the hole trapping effect by reducing the hole traps between host and MR-TADF emitter from deep (0.40 eV) to shallow (0.14/0.20 eV) ones for facilitating hole transport and exciton formation, as well as avoiding exciton quenching. And the large dihedral angle between the carbazole and MR-TADF core makes the carbazole act as a steric hindrance to inhibit molecular aggregation. Accordingly, the optimized solution-processed pure blue hyperfluorescence devices simultaneously realize record external quantum efficiency of 29.2 %, narrowband emission with a full-width at half-maximum of 16.6 nm, and pure blue color with CIE coordinates of (0.139, 0.189), which is the best result for the solution-processed organic light-emitting diodes based on MR-TADF emitters.     

Carbogenic Nanodots: Photoluminescence and Room‐Temperature Ferromagnetism

Herein, blue fluorescent carbogenic nanodots (CNDs) with room‐temperature ferromagnetism were synthesized by thermal decomposition of organic precursors at different temperatures. Photoluminescence (PL) studies show excitation‐wavelength‐dependent emission properties and PL excitation (PLE) studies confirm the triplet ground state of carbene at the zigzag edge as the fluorescent center. Room‐temperature magnetic studies reveal the ferromagnetic nature of CNDs and temperature‐dependent studies show the presence of an antiferromagnetic phase along with a ferromagnetic phase below 50 K. EPR studies reveal the presence of conduction electrons and localized spins with different g factors. Localized spins at zigzag edges are the origin of the unconventional magnetic behavior, whereas exchange coupling between conduction and localized spins are responsible for long‐range magnetic ordering.     

Synthesis, characterization and applications of vinylsilafluorene copolymers: New host materials for electroluminescent devices

Vinylsilafluorene (VSiF) was successfully synthesized and copolymerized with vinylcarbazole and methyl methacrylate via free radical copolymerization for the first time. The synthesis, photophysical properties, computational modeling studies, and organic light-emitting devices of the VSiF copolymers were presented. The good coordinated photoluminescent (PL) spectra with the absorption of blue light-emitting materials and the high energy band-gap of the VSiF copolymers were observed. Higher triplet band gap (³ E _g) to host the blue phosphorescent emitters and better HOMO and LUMO than PVK for electron and hole injection and transportation of the VSiF model compounds were revealed by density functional theory (DFT) calculations. The preliminary device results in applications of these copolymers as host materials for green phosphorescent emitters demonstrate the copolymers of VSiF and vinylcarbazole have comparable device performance of polyvinylcarazole (PVK), suggesting a bright future of VSiF as building blocks for host materials.     

Molecular Designs and Properties of Highly Efficient Blue Emitters for OLEDs

Advances made in the molecular design of modern optoelectronic materials have made significant contributions toward the development of organic electronics. The organic light-emitting devices (OLEDs) employing monodisperse or polymeric conjugated materials possess the most promising prospects. However, materials suitable for long-term use as blue light emitters are still far from optimization in terms of stability.In the past few years, interesting materials based on 9,9-diaryl-substituted fluorene as a core structure have been developed in our laboratory. We developed a series of efficient and morphologically stable pyrimidine-containing 9,9'-spirobifluorene-cored oligoaryls as pure blue emitters. The steric hindrance inherent with the molecular structure renders the material with a record-high thin-film PL quantum yield of ～95% and a glass transition temperature (Tg) of ～200 ℃.Blue OLEDs employing this thermally stable compound as the emitting host exhibit unusual endurance for high currents. Injection current over 5,000 mA/cm2 and maximal brightness of～80,000 cd/m2 had been demonstrated, representing the highest values reported for blue OLEDs under dc driving. In addition, a series of oligofluorene homologues have been synthesized. These oligofluorenes exhibit interesting reversible bipolar redox properties and excellent morphological and thermal stability. Furthermore, nondispersive ambipolar high hole and electron mobilities over 10-3 cm2/V.s can be achieved with these oligo(9,9-diarylfluorene)s. In particular, the electron mobility observed represents the highest ever reported for amorphous molecular solids. These intriguing properties together with the high quantum yields in thin films make these oligo(9,9-diarylfluorene)s are promising for OLEDs applications as efficient blue emitters. In this meeting, the synthesis and properties of these materials and their highly efficient OLEDs device characteristics will be discussed.     

Temperature-dependent photoluminescence of organic light-emitting materials: Types and characteristics of excitons involved in the emitting process

Based on experimental measurement and theoretical analysis, the temperature dependence of the photoluminescence (PL) of amorphous thin films of tris-(8-hydroxyquinoline) aluminum (Alq) and 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) has been studied. It is proposed that three types of excitons with different charge separations are involved in the steady state PL process. It is found that all three types of excitons participate in the PL process of Alq, whereas, only the first two types of radiative excitons dominate the PL process of DCJTB in the temperature range covered by the present work. The blue shift of the DCJTB PL spectra with increasing temperature has been observed and analyzed. It is suggested that the temperature-dependence of PL could be used to evaluate the radiative and conductive characteristics of organic emitters and to distinguish whether a given material would tend to be of molecular or semiconductor properties.     

Single layer light‐emitting diodes from copolymers comprised of mesogen‐jacketed polymer containing oxadiazole units and PVK

A series of copolymers PCt‐co‐Poly(N‐vinylcarbazole) were synthesized through common radical polymerization, in which P‐Ct as a kind of mesogen‐jacketed liquid crystalline polymer was introduced, and the effects of copolymers composing variation on the optical properties of the polymers were studied. The structures and properties of the copolymers were characterized and evaluated by thermogravimetric (TGA), UV, photoluminescence (PL), cyclic voltammetry (CV), and electroluminescence (EL) analyses. All the polymers enjoy high thermal stability. PL peaks in the film show blue‐shift compared with in solutions and fluorescent quantum efficiency decreased with the N‐vinylcarbazole (nvk) content increasing, which supported the efficient energy transfer from nvk units to the oxadiazole units. CV revealed that, with the incorporation of nvk to the copolymer, these copolymers had high‐lying HOMO energy levels ranging from ?5.94 to ?6.09 eV. Single‐layer light‐emitting diodes (LEDs) with the configuration of ITO/PEDOT/PCt‐nvk/Mg:Ag/Ag were fabricated, which emit a blue light around 450 and 490 nm with a maximum luminance of 703 cd/m². The device performance varies with the content of nvk and device configuration, with device configuration ( b ) and PCt‐nvk8 giving the best value of external quantum efficiency of 0.27%. We show here that by proper design copolymer structure and modification of device configuration can exhibit strong blue EL in higher external quantum efficiency. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1843–1851, 2008     

芴2,7位取代的9,9’-二芳基螺芴类化合物的合成及性能

设计并合成了一系列以三苯胺为核,芴衍生物为外围基团的有机蓝光小分子,该合成通过Suzuki反应在9-芳基芴的2位和(或)7位引入相同或不同取代基作为模块,并利用Friedel-Crafts反应将4-甲基三苯胺与这一系列模块结合.用NMR,MS和元素分析进行结构表征.荧光测试结果表明该类化合物溶液的荧光发射波长范围在442～466 nm之间,属蓝光发射.电化学测试显示该类材料的HOMO能级位于-5.15～-5.19 eV之间.差示扫描量热仪与热重分析得出化合物的玻璃化转变温度在166℃以上,热分解温度高于398℃,表明该类材料具有良好的热稳定性.     

二咔唑四苯乙烯多功能发光化合物的合成与性能

合成了一种新型的具有压致荧光变色效应的聚集诱导增强发光(PAIE)化合物二咔唑四苯乙烯; 通过核磁共振、质谱和元素分析等手段对其进行了结构表征; 利用紫外吸收光谱、荧光发射光谱、热分析和X射线衍射等手段研究了化合物的基本性能. 实验结果表明, 随着水含量的增加, 该化合物溶液荧光强度增强了171倍, 荧光量子产率提高了100倍, 表现出明显的聚集诱导增强发光效应; 在外界因素作用下该化合物固体样品可实现结晶态与无定形态的相互转变. 结晶态的荧光发射波长为450 nm, 无定形态为480 nm, 相差30 nm, 说明该化合物具有明显的压致荧光变色效应; 将该化合物用于制备发光器件, 未经优化的器件亮度达2438 cd/m2, 电流效率为2.87 cd/A, 流明效率为1.81 lm/W. 该化合物是一种多功能材料.     

Organic host materials for phosphorescent organic light-emitting diodes

Phosphorescent organic light-emitting diodes (PhOLEDs) unfurl a bright future for the next generation of flat-panel displays and lighting sources due to their merit of high quantum efficiency compared with fluorescent OLEDs. This critical review focuses on small-molecular organic host materials as triplet guest emitters in PhOLEDs. At first, some typical hole and electron transport materials used in OLEDs are briefly introduced. Then the hole transport-type, electron transport-type, bipolar transport host materials and the pure-hydrocarbon compounds are comprehensively presented. The molecular design concept, molecular structures and physical properties such as triplet energy, HOMO/LUMO energy levels, thermal and morphological stabilities, and the applications of host materials in PhOLEDs are reviewed (152 references).