点手性调控的三股铕螺旋体的非对映选择性自组装及圆偏振发光

具有超分子手性的稀土螺旋体为合成高性能稀土圆偏振发光(CPL)材料提供了结构基础.然而,稀土Ln(Ⅲ)离子较大的半径和不稳定的配位几何构型为合成高光学纯度的稀土螺旋体带来了困难和挑战.本工作通过在双三齿配体端基引入点手性的方式成功构筑了一对儿对映体纯的手性双核三股铕螺旋体,[Eu2(LRR)3](OTf)6和[Eu2(...     

不同取代位置的萘衍生两亲分子在气/液界面组装膜中的螺旋结构与圆偏振发光

Langmuir-Blodgett(LB)技术可在二维气/液界面上精确地控制分子之间的排列及堆积方式, 构建有序超薄膜及纳米组装体. 同时, 界面这一不对称环境也可有效放大组装体的手性信息, 实现超分子体系中的手性传递和手性放大. 本文研究了萘环取代位置不同的两种手性两亲分子——N,N′-双十八烷基-α-萘-L-氨基-谷氨酸二酰胺(1NLG)和N,N′-双十八烷基-β-萘-L-氨基-谷氨酸二酰胺(2NLG)在气/液界面的铺展及组装行为, 发现同分异构效应影响了两亲分子在界面的排列, 1NLG组装形成了均一的纳米带状结构, 而2NLG则形成了左手螺旋结构, 并且2NLG薄膜表现出圆偏振发光(CPL)性质, 其不对称因子(g_lum)比三维体相组装体(超分子凝胶)大23倍, 表明界面促进了超分子手性的放大.     

圆偏振发光性质的热活化延迟荧光材料及电致发光器件

具有圆偏振发光性质的热活化延迟荧光(circularly polarized thermally activated delayed fluorescence,CP-TADF)材料,因其在数据存储、生物成像以及3D显示等领域的应用前景,受到学者们的广泛关注。基于此类材料所制备的圆偏振热活化延迟荧光器件展现出优异的器件性能。本文从圆偏振热活化延迟荧光材料的发光机理及分子设计策略出发,依据CP-TADF材料构筑方法的不同,概括了其结构设计策略,系统地综述了各种类型CP-TADF材料的分子结构和光电性能的关系及其在电致发光器件领域的应用,最后探讨了目前CP-TADF材料存在的问题,并展望了其未来发展前景及挑战。     

超分子手性组装体的构建与应用

超分子手性组装体通常由多种非共价相互作用协同驱动形成,是一类具有独特手性限域微环境的软物质,对材料工程、生命科学、光学器件、催化合成等领域的发展具有重要作用.其主要构建方法分为三种;手性基元组装、手性因素诱导非手性基元组装、非手性基元对称性破缺组装.通过分析近年来的研究成果,归纳了利用这三种方法构建超分子手性组装体的一...     

超分子组装体激发态手性的响应性

圆偏振发光主要是指手性发光体系激发态的性质。由于其在信息加密、高分辨3D显示和智能传感器等领域的潜在应用而备受关注。圆偏振光除了可以通过物理方法获得,即使用线偏振片和四分之一波片的组合,还可以直接从具有光致发光或电致发光性质的手性材料中获得。目前研究者们已经开发了多种圆偏振发光材料,主要包括手性有机分子、手性金属配合物等小分子发光体系以及手性超分子组装体等复合体系。通过将手性组分与响应性功能基团结合而构筑的响应性自组装发光体系对实现智能圆偏振发光材料的发展起着重要作用。在这篇文章里,我们对手性超分子自组装发光体系对各种外界刺激的响应性能进行了总结和归纳,如光照、pH值、溶剂、温度、金属离子等。本综述通过对各种外部刺激对手性组装体激发态性能影响的总结和讨论,旨在进一步推动智能圆偏振发光材料在多学科领域的应用。     

TiO2/Eu-MCM纳米超分子材料的组装和光催化性能

利用有机相-水相界面共沉淀溶胶支持自组装方法制备粒径为15nm、孔径为8nm的分子筛Eu—MCM,它拥有734m^2／g的比表面积和1．49cm^3／g的比孔容．把TiO2组装到Eu—MCM的孔道中,组装成TiO2／Eu—MCM纳米复合材料．XRD,RAMAN和选区电子衍射花样分析表明纳米复合材料中的TiO2为锐钛型．TiO2／Eu—MCM的发光表现为Eu^3 离子的特征光谱,激发峰分别为342(^5L10),358(^5L9),378(^5L7),390(^5L6),411(^5D3),462(^5D2)和524(^5D1)nm;发射峰为579,592,613,653和701nm,归属于^5D0→^7FJ(J=0,1,2,3,4)组态间的跃迁．纳米复合材料的发光强度都要比Eu—MCM的发光强,其中43％TiO2／Eu—MCM的发光最强．荧光和紫外漫反射结果表明客体TiO2对主体分子筛存在能量传递效应．在微弱的紫外灯光照射下,TiO2／Eu—MCM纳米复合材料对苯酚的光催化氧化性能和其发光强度具有一定的相关性．29％TiO2／Eu—MCM的纳米复合材料拥有的比表面积、孔容和孔径分别为204m^2／g．0．24cm^3／g和4．7nm．29％TiO2／Eu—MCM对苯酚具有68％的最高光催化氧化产率和85％催化氧化选择性．     

基于芳香分子-糖类手性超分子组装体及功能

手性超分子组装体广泛存在于自然界中,因其在材料、化学和生物学等领域广阔的应用前景,引起了科学家们极大的兴趣。其中以糖类分子作为手性源,经分子自组装构筑手性超分子组装体的研究已成为超分子化学领域的研究热点之一。本文综述了基于糖类修饰的苝酰亚胺分子、偶氮苯分子、联苯类分子和卟啉类分子等芳香分子化合物经自组装构筑的手性超分子组装体,介绍了其在有机溶剂和水的混合溶剂、水中的凝胶性质,超分子手性特征和功能,糖分子类型与超分子组装体手性间的关系等,并对基于糖类的手性超分子组装体的前景进行了展望。     

基于手性环己二胺稀土Eu(Ⅲ)高分子在能量传递和圆偏振荧光调控方面的研究

手性(R,R)-1,2-环己二胺分别与具有偶数亚甲基烷烃链的S-M-1(4,4'-(butane-1,4-diylbis(oxy))-dibenzaldehyde),S-M-2(4,4'-(octane-1,8-diylbis(oxy))dibenzaldehyde)和S-M-3(4,4'-(dodecane-1,12-diylbis(oxy))-dibenzaldehyde)单元,通过亲核取代-消除反应合成相应的新颖柔性高分子P-1,P-2和P-3.Eu(TTA)3·2H2O分别与P-1,P-2和P-3反应制备相应的柔性稀土Eu(Ⅲ)高分子P-4,P-5和P-6.通过对烷烃主链数目的有效调控,能够有效调控稀土Eu(Ⅲ)的发光效率和圆偏振荧光的不对称因子(glum).实验证明,在一定的激发状态下,稀土高分子仅仅显示Eu(Ⅲ)的红色特征荧光,归于高分子将激发态能量基本传递给配位中心的Eu(Ⅲ)离子.通过对稀土Eu(Ⅲ)高分子的荧光寿命和量子效率表征,P-4,P-5和P-6的发光效率依次降低.P-4与P-5圆偏振荧光(CPL)的最大不对称因子(glum)分别为+0.0873和+0.0115,归属为电偶极跃迁(5D0→7F2);P-6最大不对称因子(glum)为+0.0539,归属为磁偶极跃迁(5D0→7F1).通过烷烃主链数目的差异实现对其CPL的有效调控,调控机理归于高分子折叠所引起稀土Eu(Ⅲ)不对称配位环境的变化.     

TiO2/Eu-MCM纳米超分子材料的组装和光催化性能

利用有机相-水相界面共沉淀溶胶支持自组装方法制备粒径为15 nm、孔径为8 nm的分子筛Eu-MCM, 它拥有734 m²/g的比表面积和1.49 cm³/g的比孔容. 把TiO₂组装到Eu-MCM的孔道中, 组装成TiO₂/Eu-MCM纳米复合材料. XRD, RAMAN和选区电子衍射花样分析表明纳米复合材料中的TiO₂为锐钛型. TiO₂/Eu-MCM的发光表现为Eu^3＋离子的特征光谱, 激发峰分别为342 (⁵L₁₀), 358 (⁵L₉), 378 (⁵L₇), 390 (⁵L₆), 411 (⁵D₃), 462 (⁵D₂)和524 (⁵D₁) nm; 发射峰为579, 592, 613, 653和701 nm, 归属于⁵D₀→⁷F_J (J＝0, 1, 2, 3, 4)组态间的跃迁. 纳米复合材料的发光强度都要比Eu-MCM的发光强, 其中43%TiO₂/Eu-MCM的发光最强. 荧光和紫外漫反射结果表明客体TiO₂对主体分子筛存在能量传递效应. 在微弱的紫外灯光照射下, TiO₂/Eu-MCM纳米复合材料对苯酚的光催化氧化性能和其发光强度具有一定的相关性. 29%TiO₂/Eu-MCM的纳米复合材料拥有的比表面积、孔容和孔径分别为204 m²/g, 0.24 cm³/g和4.7 nm. 29%TiO₂/Eu- MCM对苯酚具有68%的最高光催化氧化产率和85%催化氧化选择性.     

Discriminating Chiral Supramolecular Motions by Circularly Polarized Luminescence

Molecular motions are closely associated with the behaviors and properties of organic materials. However, monitoring molecular motions is challenging. Herein, a chiral supramolecular system consisting of L-/D-phenylalanine (LPF/DPF) as a chiral inducer and an achiral tetraphenylethene derivative (TPEF) as a molecular rotor has been proposed and explored for real-time discriminating the supramolecular motions by the visualization of circularly polarized luminescence (CPL) signal variations. Derived from the ordered molecular motions of TPEF induced by LPF/DPF, highly organized aggregates have been progressively assembled in a controlled manner with differentiated morphologies, including spherical particles, one-dimensional fibers, and floor-shaped supercrystals. Notably, increasing level of ordered aggregates, in turn, led to quenching emissions, while the CPL signals have been dramatically amplified accompanying by a sharp enhancement of luminescence dissymmetry factors (g_lum) from nearly 0 to −0.1. The significant amplification of CPL is attributed to the ordered aggregates of supramolecules, leading to the decrease of electric transition dipole moments in supramolecular system. As a result of the chiral supramolecular motions powered by supramolecular crystallization, the supramolecular motions are conveniently discriminated by visual CPL signal variation with an enhancement of g_lum value from 0 to −0.1 in real time.     

Multiply Twisted Chiral Macrocycles Clamped by Tethered Binaphthyls Exhibiting High Circularly Polarized Luminescence Brightness

Chiral macrocyclic dimers, trimers, and tetramers composed of paraphenylene and tethered binaphthyl were synthesized, and their molecular structures and chiroptical properties were investigated. X-ray analysis and theoretical calculations revealed that multiple twisted molecular structures – dimers, trimers, and tetramers – adopt figure-of-eight, Möbius triangle, and concave rectangle structures, respectively. These homologues have large ϵ values in their UV-vis absorption spectra because of the π-conjugation of the naphthalene-phenylene-naphthalene frameworks. Owing to the shape-persistent ring structure and tethering with −OCH₂CH₂O−, high fluorescence quantum yields and a relatively high dissymmetry factor g_CPL in circularly polarized luminescence (CPL) spectra were achieved. This results in CPL brightness (B_CPL) of over 100, which is greater than that of the conventional organic CPL dye.     

手性有机光电功能材料及其圆偏振光发射与探测

手性有机半导体由于其新颖的性质引起了有机光电领域极大的研究兴趣. 将手性引入有机半导体材料不仅可以调控聚集态结构影响载流子输运进而影响光电器件的性能, 而且催生了圆偏振光直接发射与探测材料与器件的产生与发展. 手性材料与圆偏振光之间的相互作用使得其在3D显示、量子通讯、信息存储与处理等领域展示出广泛的应用前景. 本综述总结近年来手性有机光电材料及器件的研究进展, 主要围绕手性对有机半导体材料性质与器件性能的影响展开, 聚焦于手性有机半导体的圆偏振光直接发射与探测等研究, 旨在进一步为手性有机光电子领域的发展提供系统的认识.     

Circularly Polarized Luminescence from Simple Organic Molecules

This article aims to show the identity of “circularly polarized luminescent active simple organic molecules” as a new concept in organic chemistry due to the potential interest of these molecules, as availed by the exponentially growing number of research articles related to them. In particular, it describes and highlights the interest and difficulty in developing chiral simple (small and non‐aggregated) organic molecules able to emit left‐ or right‐circularly polarized light efficiently, the efforts realized up to now to reach this challenging objective, and the most significant milestones achieved to date. General guidelines for the preparation of these interesting molecules are also presented.     

Circularly Polarized Luminescence Switching in Small Organic Molecules

The circularly polarized luminescence (CPL) switching is of significant interest for applications in security technologies and sensing devices. Small organic molecules (SOMs) show several advantages over metal complexes, supramolecular assemblies, and polymers. Therefore, the recent progress on the CPL switching in SOMs is here reviewed. The results are summarized based on the strategies used to tune factors that influence the emission properties, and thus, to realize CPL switching. The strategies that have been adopted include promoting the excimer formation of fluorescent units, changing the conformation of fluorophores, tuning the electronic structure of the π-skeleton/substituent, and modulating the intramolecular charge-transfer dynamics.     

手性有机小分子圆偏振发光的研究进展

圆偏振发光不仅能直观地反映手性发光体系的激发态结构信息,而且在3D显示、自旋信息通讯、信息存储与处理、CPL激光、生物探针等领域具有广泛的应用前景.因此,近年来圆偏振发光材料引起了人们越来越多的兴趣与关注,成为有机发光功能材料领域一个新的研究热点.本综述总结近年来关于手性有机小分子圆偏振发光的研究进展,主要围绕具有中心手性、轴手性、面手性和螺旋手性的圆偏振发光有机小分子展开介绍.     

Magnetic Circularly Polarized Luminescence from PtIIOEP and F2-ppyPtII(acac) under North-up and South-up Faraday Geometries

The magnetic circularly polarized luminescence (MCPL) and photoluminescence (PL) spectra of achiral (2,3,7,8,12,13,17,18-octaethylporphyrinato)platinum(II), PtOEP , and [2-(4′,6′-difluorophenyl)pyridinato-N,C^2′]platinum(II) acetylacetonate-O,O, F₂-ppyPt(acac) , in toluene and dichloromethane solutions were recorded under an external magnetic field of 1.6 T with N-up and S-up Faraday geometries. The MCPL signs of PtOEP and F₂-ppyPt(acac) were controlled solely by changing the N-up and S-up geometries. The MCPL/PL wavelengths of F₂-ppyPt(acac) in solutions were varied by the ratio of the monomeric and excimeric species.     

Ring-Opened Hemiporphyrazines: Helical Molecules Exhibiting Circularly Polarized Luminescence

We designed and synthesized a new type of small helical molecule exhibiting intense circularly polarized luminescence (CPL) ( 1_2H ) by modifying a 20π-electron hemiporphyrazine with a large transition magnetic dipole moment. The hemiporphyrazine ring was opened and one additional pyridine unit was introduced, resulting in an overlap of two pyridine rings. X-ray structure analysis confirmed that 1_2H and its zinc complex ( 1_Zn ) adopt a helical geometry. A racemic mixture of 1_Zn was resolved into two enantiomers ((P)- and (M)- 1_Zn ), which exhibited CPL with a high luminescence dissymmetry factor (g_lum) value of ±2.1×10⁻². The origin of the large g_lum value was rationalized by means of DFT calculations. Helical structures could be formed in a diastereoselective manner by covalently attaching chiral units to the skeleton ( 1’_2H and 1’_Zn ). 1_Zn was found to possess chiral recognition ability for amines.     

Dual Upconverted and Downconverted Circularly Polarized Luminescence in Donor–Acceptor Assemblies

Through mimicking both the chiral and energy transfer in an artificial self‐assembled system, not only was chiral transfer realized but also a dual upconverted and downconverted energy transfer system was created that emit circularly polarized luminescence. The individual chiral π‐gelator can self‐assemble into a nanofiber exhibiting supramolecular chirality and circularly polarized luminescence (CPL). In the presence of an achiral sensitizer Pd^II octaethylporphyrin derivative, both chirality transfer from chiral gelator to achiral sensitizer and triplet‐triplet energy transfer from excited sensitizer to chiral gelator could be realized. Upconverted CPL could be observed through a triplet–triplet annihilation photon upconversion (TTA‐UC), while downconverted CPL could be obtained from chirality‐transfer‐induced emission of the achiral sensitizer. The interplay between chiral energy acceptor and achiral sensitizer promoted the communication of chiral and excited energy information.