圆偏振热活化延迟荧光材料及其器件的研究进展

圆偏振热活化延迟荧光材料具有分子结构易修饰、激子利用率高及圆偏振发光等特点,在光学信息存储、3D显示、发光器件和数据加密等领域具有广阔应用前景.利用此类材料作为发光层制备的圆偏振有机发光二极管,能够同时实现高发光不对称因子和理论上达100%的激子利用率,对发展低功耗和高性能有机发光二极管至关重要.近年来,通过不断的分子结构设计与优化,该类材料在有机发光二极管中的电致发光效率不断提高,但是仍然存在不对称因子低及效率滚降严重等问题.基于此,整理了目前已报道的圆偏振热活化延迟荧光化合物,重点讨论了其分子结构设计与光物理性质、圆偏振特性以及电致发光性能的关系规律,并对高性能圆偏振热活化延迟荧光材料的制备及其在有机发光二极管中的应用进行了展望.     

高分子发光材料研究进展

高分子发光材料具有可溶液加工的特点,适于制备低成本、大面积发光器件,在平板显示和固体照明领域具有潜在的应用前景.近年来,高分子发光材料在发光机制、材料体系和器件性能等方面均取得了重要进展,各项性能得到了大幅度提升.本文从材料和器件角度,围绕高分子荧光材料、高分子磷光材料和高分子热活化延迟荧光材料的分子设计策略,总结和评述了高分子荧光材料的颜色调控和效率提升途径,高分子磷光材料的磷光掺杂剂、高分子主体、拓扑结构等因素对发光性能的影响规律,以及高分子热活化延迟荧光材料的设计原理和典型材料体系.同时,分析了高分子发光材料未来发展面临的机遇和挑战.     

高分子热活化延迟荧光材料研究进展

高分子热活化延迟荧光材料能够利用热活化的反向系间窜越过程将三线态激子转变为单线态激子而发出荧光,理论上可以实现100%的内量子效率,突破了传统高分子荧光材料内量子效率不超过25%的极限,因而代表了未来低成本高效率高分子发光材料的发展方向。 近年来,高分子热活化延迟荧光材料在分子设计方面取得了重要进展,形成了主链型、侧链型和树枝状高分子热活化延迟荧光材料等材料体系,同时其器件性能得到了大幅提升,部分材料的器件效率达到了高分子磷光材料的水平。 本文从材料和器件两个方面,围绕高分子热活化延迟荧光材料的分子结构、光物理特性和器件性能,总结和评述了国内外研究者在该领域方向的研究进展,并分析了未来发展面临的机遇和挑战。     

聚集诱导延迟荧光材料及器件研究进展

热活化延迟荧光(TADF)材料无需贵金属参与即可实现单线态和三线态激子的全利用,成为了有机电致发光的研究热点.但是目前大部分TADF材料都表现出严重聚积诱导发光猝灭现象,这对其应用和发展不利.聚集诱导延迟荧光材料作为一种新型TADF材料,具有独特的聚集诱导荧光增强现象引起科研工作者极大兴趣.基于聚集诱导延迟荧光材料分子设计及其光物理性能和器件研究具有重要意义.将依据不同电子受体单元,对聚集诱导延迟荧光材料的发光原理、设计策略及其有机发光器件的最新进展进行简要综述,并对其发展做出展望.     

热活化延迟荧光聚合物及其电致发光器件

热活化延迟荧光(TADF)聚合物,不仅具有小分子TADF材料高的激子利用效率特性,而且还具备分子多样性好、可溶液加工、低成本、以及易实现大面积柔性器件等诸多优势,在近几年受到广泛的关注并展现了良好的应用前景。本文从TADF聚合物分子设计原理、器件结构及发光机理出发,依据TADF聚合物的构筑方法不同,概括了其结构设计策略,详述了各种类型TADF聚合物的分子结构和光电性能及其在有机电致发光器件领域应用的研究进展,最后探讨了TADF聚合物存在的问题,并展望了其发展前景。     

电子给体-受体型热活化延迟荧光蓝光材料研究进展

热活化延迟荧光材料由于其最低激发单重态和最低激发三重态之间的能级差较小,三重态激子可以通过反向系间窜越过程上转换到单重态,实现无贵金属添加的三重态激子参与的荧光发射,大大提高了发光效率,解决了传统荧光有机发光二极管(OLED)内/外量子效率(≤25%/≤5%)低下的问题;与磷光OLED相比,避免了使用贵金属,在造价方面具有更大优势.在类型众多的热活化延迟荧光(TADF)材料中,由于电子给体-受体型分子合成简单,性能出众而成为近年来的研究热点.另一方面,高效蓝光材料的稳定性及色纯度问题一直是该领域研究亟待解决的难题.本文将依据不同电子给受体单元,对电子给体-受体型热活化延迟荧光蓝光材料及其OLED器件的最新进展、发光原理和设计原则进行了简要综述,并对其发展作出展望.     

基于八氢联萘酚的大位阻手性发光材料构建及光电性质研究

以手性发光材料为发光中心制备能够直接发射出圆偏振电致发光(circularly polarized electroluminescence, CPEL)的器件, 即CP-organic light-emitting diode (CP-OLED), 在3D显示领域有极大的应用前景. 本工作设计了基于八氢联萘酚的手性热激活延迟荧光材料(S/R)-OBN-tBuCz, 八氢联萘酚作为有效的手性源, 而叔丁基咔唑取代的氰基苯作为高效发光部分. 八氢联萘酚外围较多的氢原子以及较大的叔丁基可以有效增加手性发光分子的空间位阻, 降低堆积效应, 抑制浓度淬灭, 有效提升器件的发光效率. 所合成的手性发光材料展现出明亮的绿光发射(523 nm)、高的荧光量子产率(85.2%)、较小的单线态-三线态能级差ΔE_ST (0.05 eV)和优秀的热稳定性. 圆二色(CD)与圆偏振发光(CPL)光谱显示出明显的对称圆偏振发光信号, 且溶液中的g_PL为+8.6×10^-4和–6.5×10^-4. 基于(S/R)-OBN-tBuCz的电致发光器件表现出优异性能: 起亮电压为3.9 V, 最大亮度为27709 cd•m^-2, 最大电流效率为43.8 cd•A^-1, 最大功率效率为33.5 lm•W^-1, 最大外量子效率为12.4%, 效率滚降很低, 并显示出明显的圆偏振电致发光信号, g_EL分别为+1.57×10^-3和–0.90×10^-3. 大位阻手性发光材料的设计有助于实现高效的CP-OLED, 该研究能促进手性发光材料及圆偏振电致发光器件等相关研究领域的发展.     

有机电致发光器件中的双极性蓝光荧光材料

双极性蓝光荧光材料因其双极传输特性和发光特性,为有机电致发光器件性能提升及结构简化提供了新途径。大多数双极性蓝光荧光材料在结构上符合电子给体-π桥-电子受体(D-π-A),根据电子受体单元,本文将其分为二苯磷/磺酰类、二米基硼类、五元杂环类、六元氮杂环类等,讨论了各类材料结构特点及在器件中的应用性能,对非D-π-A型材料也进行了总结。同时,介绍了热活化延迟荧光特性的双极性蓝光荧光材料的进展情况。最后,对双极性蓝光荧光材料中存在的问题进行了提炼,并展望了其发展前景。     

分子筛限域碳点实现超长寿命热活化延迟荧光

正热活化延迟荧光(TADF)材料由于其较小的单重态-三重态能级差(ΔEST),三重态可通过反系间窜跃转向单重态而发出延迟荧光,从而获得潜在的高荧光量子效率。这类材料独特的发光性能使其在光电器件、生物成像、传感等应用方面展现出优势~(1,2)。但目前报道的TADF材料主要集中于纯有机材料和有机金属络合物,其延迟荧光寿命     

聚苯乙烯类发光材料研究进展

高分子发光材料具有良好的溶液加工特性,是发展低成本、大面积平板显示和固体照明器件的重要基础材料。聚苯乙烯类发光材料在合成方法上具有聚合方法简单、无需使用催化剂、无卤素原子残留等优势,在化学结构上具有非共轭主链结构和易于引入功能化侧链等特点,在发光特性上具有宽带隙特征,近年来发展成为一类重要的高分子发光材料。本文从材料和器件角度,围绕聚苯乙烯类荧光材料、聚苯乙烯类磷光材料和聚苯乙烯类热活化延迟荧光材料的分子设计和电致发光性能,综述了聚苯乙烯类发光材料的研究进展,分析总结了其未来发展所面临的机遇和挑战。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.