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.     

联萘基手性发光材料的圆偏振发光

本文综述了近年来基于联萘基结构的圆偏振发光材料的研究工作.从光致发光和电致发光两方面总结了不同体系下联萘基材料的圆偏振发光,为相关领域的研究者提供了设计思路,并对圆偏振发光材料的研究发展方向进行了展望.     

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.     

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.     

圆偏振发光高分子的研究

综合评述了近年来有关圆偏振发光高分子的研究，包括圆偏振发光高分子的潜在应用及其在发光高分子理论研究上的意义，圆偏振发光高分子的类型与性能表征等。并提出了三条获得高度圆偏振发光高分子的可能途径。     

无机分子纳米材料的研究进展

无机分子纳米材料是至少在一个维度上为纳米尺寸的分子及以其为单元组成的材料。由于其特殊的结构和性质，这种材料可以作为未来纳米分子电子器件、小分子吸附及储存材料。本文将从合成、结构、性质、应用等方面, 结合最新进展对这一充满活力并有着应用前景的领域作一简要概述。     

无机纳米材料的光化学合成

无机纳米材料的合成是纳米科学发展的前提和基础之一。区别于传统的高温湿化学合成法,光化学方法在无机纳米材料的合成中表现出许多优点,并在近年来受到了广泛关注。本文分三个部分综述了近年来光化学方法在无机纳米材料合成中的应用,具体包括贵金属纳米材料的光化学合成与负载,半导体纳米材料的光化学合成以及表面等离子体共振诱导的各向异性金属纳米晶合成。最后,在总结光化学方法在无机纳米材料合成中体现出的优势及目前研究仍存在不足的基础上,我们对其未来可能的发展方向进行了展望。     

气相法合成一维无机纳米材料的研究进展

一维无机纳米材料是研究电子传输行为、光学特性和力学机械性能等物性的尺寸和维度效应的理想系统，将在构筑纳米电子和光电子器件等集成线路和功能性元件的进程中充当非常重要的角色，已成为当前纳米材料科学领域的前沿和热点。本文将从一维无机纳米材料的合成、表征和物性研究等方面，结合近年来国内外的最新进展对这一新兴领域作一概述。     

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。     

Circularly Polarized Light Triggers Biosensing Based on Chiral Assemblies

Chiral assemblies have attracted great interest because of their many potential applications, such as in chiral sensing, asymmetric catalysis, and optical devices. Here, by using specific DNAzymes, a chiral core–satellite assembly consisting of a DNAzyme-driven spiny nanorod dimer core and upconversion nanoparticle (UCNP) satellite was constructed. The chirality of this assembly originates from the geometry chirality. This chiral assembly can be used as a photothermally activated probe for the simultaneous detection of multiple analytes in living cells. Under illumination with 980 nm left circularly polarized (LCP) light, this probe was used to quantify and visualize intracellular metal ions.     

Molecular Design,Circularly Polarized Luminescence,and Helical Self‐Assembly of Chiral Aggregation‐Induced Emission Molecules

Aggregation‐induced emission luminogens (AIEgens) are a new class of luminophors, which are non‐emissive in solution, but emit intensively upon aggregation. By properly designing the chemical structures of the AIEgens, their aggregation process can be tuned towards a desired direction to give diverse novel luminescent architectures of micelles, rods, and helical fibers. AIEgens represent a kind of promising building block for the fabrication of luminescent micro/nanostructures with controllable morphologies. In this review, we describe our recent work in this research area, focusing on the molecular design, circularly polarized luminescence properties, and helical self‐assembly behavior of AIEgens.     

Chiral Oligothiophenes with Remarkable Circularly Polarized Luminescence and Electroluminescence in Thin Films

This work reports the first observation of circularly polarized electroluminescence (CPEL) in thin films of self-organized oligothiophenes. Four new 1,4-phenylene and 9H-carbazole-based oligothiophenes were ad hoc designed to ensure efficient spontaneous formation of chiral supramolecular order. They were easily synthesized and their chiroptical properties in thin films were measured. Circularly polarized luminescence (CPL) spectra revealed g_lum in the order of 10⁻² on a wide wavelengths range, originating from their self-organized chiral supramolecular organization. These molecules have reasonable properties as organic semiconductors and for this reason they can constitute the active layer of circularly-polarized organic light-emitting diodes (CP-OLEDs). Thus, we could investigate directly their electroluminescence (EL) and CPEL, without resorting to blends, but rather in a simple multilayer device with basic architecture. This is the first example of a CP-OLED with active layer made only of a small organic compound.     

Circularly Polarized Luminescence from Helically Chiral N,N,O,O‐Boron‐Chelated Dipyrromethenes

Helically chiral N,N,O,O‐boron chelated dipyrromethenes showed solution‐phase circularly polarized luminescence (CPL) in the red region of the visible spectrum (λ_em(max) from 621 to 663 nm). The parent dipyrromethene is desymmetrised through O chelation of boron by the 3,5‐ortho‐phenolic substituents, inducing a helical chirality in the fluorophore. The combination of high luminescence dissymmetry factors (|g_lum| up to 4.7 ×10^?3) and fluorescence quantum yields (Φ_F up to 0.73) gave exceptionally efficient circularly polarized red emission from these simple small organic fluorophores, enabling future application in CPL‐based bioimaging.     

Quantifying the Overall Efficiency of Circularly Polarized Emitters

An increasing number of circularly polarized luminescence (CPL) molecular emitters has been developed in recent years and many of them are intended for applications in which high overall CPL efficiencies are required. In order to have a complete picture of the efficiency of a CPL emitter, dissymmetry factor (g_lum) is not enough. In the following we propose a new quantity, named CPL brightness (B_CPL), which takes into account absorption extinction coefficient and quantum yield along with the g_lum factor. We calculated B_CPL value for more than 180 compounds reported in the literature and we analyse data distribution for the main classes of CPL molecular emitters. This tool can be employed to put into context new CPL active compounds and to direct the choice of molecular systems for specific CPL applications.     

Ruthenium Complexes Bearing Axially Chiral Bipyridyls: The Mismatched Diastereomer Showed Red Circularly Polarized Phosphorescence

Ruthenium^II complexes bearing three axially chiral bipyridyl ligands were synthesized as a new family of chiral complex dyes, and Δ-(S)- and Λ-(S)-diastereomers were obtained. The X-ray crystal structure analyses, spectroscopy, and DFT calculations suggested that all the bipyridyls maintained chirality in both the ground and excited states, and the Δ-(S)- and Λ-(S)-isomers are the matched (more relaxed) and mismatched (more constrained) pairs, respectively. The mismatched Λ-(S)-isomer exhibited red circularly polarized phosphorescence (CPP) both in solution and in the solid state. The solution state CPP is the most intense of ruthenium complexes, while the solid state CPP is the first example of them. It is supposed that, for the Λ-(S)-isomer, the six cumulative CH/π interactions suppress further distortion in the T₁ state.     

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.     

Planar Chiral Organoboranes with Thermoresponsive Emission and Circularly Polarized Luminescence: Integration of Pillar[5]arenes with Boron Chemistry

Enantiopure molecules based on macrocyclic architecture are unique for applications in enantioselective host‐guest recognition, chiral sensing and asymmetric catalysis. Taking advantage of the chiral transfer from the intrinsically planar chirality of pillar[5]arenes, we herein present an efficient and straightforward approach to achieve early examples of highly luminescent chiral systems ( P5NN and P5BN ). The optical resolution of their enantiomers has been carried out via preparative chiral HPLC, which was ascribed to the molecular functionalization of pillar[5]arenes with π‐conjugated, sterically bulky triarylamine (Ar₃N) as an electron donor and triarylborane (Ar₃B) as an acceptor. This crucial design enabled investigations of the chiroptical properties, including circular dichroism (CD) and circularly polarized luminescence (CPL) in the solid state. The intramolecular charge transfer (ICT) nature in P5BN afforded an interesting thermochromic shift of the emission over a wide temperature range.