聚集诱导发光体系:化合物种类、发光机制及其应用

聚集诱导发光(AIE)体系是近年来备受关注的一个研究领域,目前该领域已经积累了较为丰富的AIE化合物的分子设计理念和相应的对AIE机制的理解。AIE体系的研究为固态强发光材料特别是备受聚集发光猝灭难题困扰的有机电致发光材料提供了全新的分子设计思路。本文纵观该领域的研究进展,对AIE化合物种类、发光机制及其相关应用做出了较为详尽的综述报道。具有AIE性质的化合物主要包括多芳基取代的杂环化合物、多芳基乙烯类化合物、分子内电荷转移化合物、含有氢键的化合物、聚合物等。这些化合物的AIE发光机制也各有不同,包括分子内旋转受限、非辐射失活衰减受限、分子构象扭曲以避免形成激基缔合物以及利用特殊的分子堆积方式如J-聚集、交叉分子堆积、由分子间的C—H…π作用或特殊的氢键作用形成相应的发光聚集体等。基于其特殊的AIE性能,AIE化合物可广泛应用于化学传感、生物传感、生物标记、电致发光以及逻辑门器件等领域。     

聚集诱导发光：研究高分子科学的一种新方法

高分子科学在人类生活和现代社会中发挥了越来越重要的作用,深入理解高分子材料的构效关系及性能尤为重要.现代仪器表征手段受制于非原位、样品制备过程冗杂等因素,很难直接"看到"测试过程.荧光成像技术可以清楚地"看到"材料的结构及形态变化,受到广泛关注.但是,传统荧光分子易发生聚集导致发光淬灭现象,限制其应用.相反,聚集诱导发光(AIE)分子基于分子运动受限的发光机理,在聚集态具有强的发光信号,加之荧光量子效率高、对外界刺激灵敏等优点,现已成为化学和材料等领域的前沿.本专论从AIE的工作原理出发,较系统地总结了基于AIE独特的分子可视化技术如何成为原位研究高分子科学的新方法:监测聚合物的溶液性质,如聚合过程、溶度参数及构效关系等;监测聚合物的聚集体性质,如链段固态分子运动、玻璃化转变、相分离及结晶度等.最后对AIE技术在高分子科学领域的未来发展进行了展望.     

二苯乙烯基蒽衍生物:聚集诱导发光性质、机理及应用

与传统的发光分子相比,具有聚集诱导发光(AIE)性质的分子,在聚集态或固态条件下,由于独特的分子结构和聚集态结构,表现出显著增强的荧光发射,因而在光电器件、生物化学检测等领域展现出广阔的应用前景。本文总结了二苯乙烯基蒽(DSA)及其衍生物的AIE性质,分析了DSA类分子AIE现象的机理,如分子内转动受限、扭曲的分子结构及分子间聚集结构等,同时介绍了此类分子在固态发光、刺激-响应材料,以及生物检测和生物成像等方面的应用。     

聚集诱导发光分子的光电功能与器件应用

光电功能分子通常以薄膜和聚集体的形式显示功能, 聚集诱导发光（AIE）分子体系的发现为解决固态下聚集诱导荧光猝灭（ACQ）难题提供了新的思路. 本文总结了近年来本课题组发展的一系列AIE 分子, 侧重介绍这些AIE 分子的光电功能与器件应用, 特别是在有机电致发光器件和有机激光方面的应用. AIE 材料显示非常高的电致发光效率, 在显示与白光器件方面潜力巨大. 在发展电泵有机激光方面, AIE 材料特点突出, 是最有前景的一类材料.     

聚集诱导发光机理研究

与传统荧光生色团聚集后导致荧光猝灭相反,有一类化合物在单分子状态下荧光微弱甚至观察不到荧光,而在聚集状态下荧光显著增强,这就是聚集诱导发光(AIE)现象。AIE现象独特的优越性使得众多研究组开发出越来越多的新AIE体系,其机理也被广泛而深入地研究。本文总结了目前为止已经提出的AIE机理,包括分子内旋转受限、分子内共平面、抑制光物理过程或光化学反应、非紧密堆积、形成J-聚集体以及形成特殊激基缔合物等;着重评述了目前研究最为全面、适用范围最广的分子内旋转受限机理。同时介绍了一些基于这些机理设计的新AIE体系。     

聚集诱导发光材料在聚合物制备及性能检测中的应用进展

聚集诱导发光(AIE)材料因其独特的发光性能,已在荧光检测、生物成像及有机发光器件等领域展现出较为广阔的应用前景。本文综述了AIE材料在监测聚合物制备过程(本体聚合、溶液聚合、乳液聚合及悬浮聚合过程等)中的应用,介绍了利用AIE分子的荧光信号响应检测聚合物玻璃化转变温度、粘度、相分离程度、分子量等物理性能的研究,为AIE材料在聚合过程可视化监测及聚合物荧光功能化领域的应用提供了参考。最后对AIE材料在高分子科学研究中的应用前景进行了展望。     

聚集诱导发光分子寡聚体研究进展

分子聚集行为与细胞内多种代谢过程息息相关,如细胞衰老过程中色斑形成,Aβ肽在阿尔茨海默病病人的脑中聚集行为等.定量化的研究分子聚集效应对于研究分子间的弱相互作用,分子聚集成核过程至关重要.目前,针对聚集效应初期分子寡聚体形成过程的研究仍然处于初期阶段.聚集诱导发光(aggregation-induced emission,AIE)为研究分子聚集行为提供了一种直观、便捷的策略.但是,由于聚集过程的难以精细控制,定量化描述聚集分子数目与发光行为的关系仍然是巨大的挑战.本综述对近期制备聚集诱导发光分子寡聚体的工作进行汇总.根据形成分子寡聚体的作用力的不同,将目前构建荧光分子寡聚体方法分为以下4类:化学成键作用、主客体相互作用、DNA限域作用和微纳空间限域作用.进一步地,还讨论了分子聚集体的发光行为.通过本综述,有望推动AIE分子寡聚体发光性质的量化研究并为研究分子聚集成核过程带来一定的启示.     

TPE核的螺旋手性

正2001年,唐本忠等基于多苯环取代的噻咯衍生物在良溶剂中不发光或发光微弱,而在聚集状态下荧光大大增强的现象,率先提出了"聚集诱导发光(aggregation-induced emission,AIE)"的概念~1,经过大量实验验证和理论模拟,他们提出了分子内运动受限是导致化合物产生AIE现象的主     

聚集诱导发光应用研究进展

传统的荧光化合物在聚集态时,会导致荧光猝灭;而聚集诱导发光(AIE)化合物在溶液中单分子状态时呈现弱的荧光,但当形成聚集态时发出强的荧光,这是由于分子内旋转受阻(RIR)和聚集形态的改变所致.综述了2008年以来聚集诱导发光最新应用研究进展,如用以检测离子、气体、有机小分子、爆炸物、蛋白、酶等化学/生物传感器;向传统的聚集引起猝灭化合物引入AIE单元,制备高效固态发光器件等;通过压力、热、溶剂蒸汽等调控聚集态,构建可逆的刺激性多重响应材料;发展与生物体具有良好兼容性的聚集体杂化纳米颗粒(如荧光硅纳米颗粒、聚合物胶束、电解质等),以用于生物体内成像、结构解析及检测等.     

具有聚集诱导发光性质的近红外荧光染料

聚集诱导发光(AIE)现象的发现为解决传统有机荧光分子在高浓度和聚集形态下存在的荧光猝灭问题提供了最佳方案,并实现了在光电器件、化学传感、生物成像和靶向治疗等众多领域的广泛应用。随着对AIE发光机理研究的不断深入,AIE分子体系得到了极大的扩展。其中,一类具有给体-受体结构的AIE分子能够显著降低分子能隙,使发光分子波长从可见光区(400~700 nm)延伸到近红外(NIR)区(700~1700 nm)。由于NIR发光分子在生物医学领域中的独特优势,其已成为目前AIE研究的热点。随着对NIR分子设计及应用的不断探索,附加不同功能且发光波长更长的AIE分子也被开发出来了,并实现了对生物体特定组织的NIR荧光成像、光声成像、光动力治疗和光热治疗等。本文总结了近年来具有AIE性能的NIR荧光分子的结构及其在生物医学领域的相关应用。     

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.