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1.
White‐Light Emission Strategy of a Single Organic Compound with Aggregation‐Induced Emission and Delayed Fluorescence Properties 下载免费PDF全文
Dr. Zongliang Xie Dr. Chengjian Chen Shidang Xu Jun Li Prof. Yi Zhang Prof. Siwei Liu Prof. Jiarui Xu Prof. Zhenguo Chi 《Angewandte Chemie (International ed. in English)》2015,54(24):7181-7184
A novel white‐light‐emitting organic molecule, which consists of carbazolyl‐ and phenothiazinyl‐substituted benzophenone (OPC) and exhibits aggregation‐induced emission‐delayed fluorescence (AIE‐DF) and mechanofluorochromic properties was synthesized. The CIE color coordinates of OPC were directly measured with a non‐doped powder, which presented white‐emission coordinates (0.33, 0.33) at 244 K to 252 K and (0.35, 0.35) at 298 K. The asymmetric donor–acceptor–donor′ (D‐A‐D′) type of OPC exhibits an accurate inherited relationship from dicarbazolyl‐substituted benzophenone (O2C, D‐A‐D) and diphenothiazinyl‐substituted benzophenone (O2P, D′‐A‐D′). By purposefully selecting the two parent molecules, that is, O2C (blue) and O2P (yellow), the white‐light emission of OPC can be achieved in a single molecule. This finding provides a feasible molecular strategy to design new AIE‐DF white‐light‐emitting organic molecules. 相似文献
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Yahui Zhang Lingwei Kong Jianbing Shi Bin Tong Junge Zhi Xiao Feng Yuping Dong 《中国化学》2015,33(7):701-704
A new type of AIE molecules based on hexaphenyl‐1,3‐butadienes was reported with respect to the synthesis and characterization. This material exhibited different maximum emission wavelength and enhanced emission intensity at different aggregate state (amorphous and crystalline state). 相似文献
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Boron Diiminate with Aggregation‐Induced Emission and Crystallization‐Induced Emission‐Enhancement Characteristics 下载免费PDF全文
Ryousuke Yoshii Amane Hirose Kazuo Tanaka Prof. Yoshiki Chujo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(27):8320-8324
Organoboron complexes having aggregation‐ and crystalization‐induced emission properties are presented. The series of boron diiminates were synthesized and the emission behaviors of the synthesized compounds were investigated. Finally, it was found that significant enhancement of the emission depended on the crystallinity in the solid states. 相似文献
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Aggregation‐Induced Emission and Aggregation‐Promoted Photo‐oxidation in Thiophene‐Substituted Tetraphenylethylene Derivative 下载免费PDF全文
Dr. Linna Zhu Rui Wang Dr. Luxi Tan Xianfeng Liang Dr. Cheng Zhong Dr. Fei Wu 《化学:亚洲杂志》2016,11(20):2932-2937
Aggregation‐induced emission combined with aggregation‐promoted photo‐oxidation has been reported only in two works quite recently. In fact, this phenomenon is not commonly observed for AIE‐active molecules. In this work, a new tetraphenylethylene derivative (TPE‐4T) with aggregation‐induced emission (AIE) and aggregation‐promoted photo‐oxidation was synthesized and investigated. The pristine TPE‐4T film exhibits strong bluish‐green emission, which turns to quite weak yellow emission after UV irradiation. Interestingly, after solvent treatment, the weakly fluorescent intermediate will become bright‐yellow emitting. Moreover, the morphology of the TPE‐4T film could be regulated by UV irradiation. The wettability of the TPE‐4T microcrystalline surface is drastically changed from hydrophobic to hydrophilic. This work contributes a new member to the aggregation induced photo‐oxidation family and enriches the photo‐oxidation study of tetraphenylethylene derivatives. 相似文献
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A new type of fluorescent polymeric micelles is developed by self‐assembly from a series of amphiphilic block copolymers, poly(ethylene glycol)‐b‐poly[styrene‐co‐(2‐(1,2,3,4,5‐pentaphenyl‐1H‐silol‐1‐yloxy)ethyl methacrylate)] [PEG‐b‐P(S‐co‐PPSEMA)]. Their capability of loading doxorubicin (DOX) is investigated by monitoring the loading content, encapsulation efficiency, and photophysical properties of micelles. Förster resonance energy transfer from PPSEMA to DOX is observed in DOX‐loaded micelles, which can serve as an indication of successful encapsulation of DOX in these micelles. The application of this new type of fluorescent polymeric micelles as a fluorescent probe and an anticancer drug carrier simultaneously is explored by studying the intracellular uptake of DOX‐loaded micelles.
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Photoactivatable Aggregation‐Induced Emission Fluorophores with Multiple‐Color Fluorescence and Wavelength‐Selective Activation 下载免费PDF全文
Lu Peng Yue Zheng Xiaoyan Wang Prof. Aijun Tong Prof. Yu Xiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4326-4332
Photoactivatable (caged) fluorophores are widely used in chemistry, materials, and biology. However, the development of such molecules exhibiting photoactivable solid‐state fluorescence is still challenging due to the aggregation‐caused quenching (ACQ) effect of most fluorophores in their aggregate or solid states. In this work, we developed caged salicylaldehyde hydrazone derivatives, which are of aggregation‐induced emission (AIE) characteristics upon light irradiation, as efficient photoactivatable solid‐state fluorophores. These compounds displayed multiple‐color emissions and ratiometric (photochromic) fluorescence switches upon wavelength‐selective photoactivation, and were successfully applied for photopatterning and photoactivatable cell imaging in a multiple‐color and stepwise manner. 相似文献
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Jan Freudenberg Dr. Frank Rominger Prof. Uwe H. F. Bunz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(47):16749-16753
The synthesis of five novel distyrylbenzene (DSB) derivatives, featuring a central tetraphenylbenzene core, is reported. The targets show aggregation‐induced emission (AIE), which, however, is substituent‐dependent. For the pure hydrocarbon and derivatives that do not carry (+M) or (?M) substituents, classic AIE behavior is observed, that is, the DSBs are non‐fluorescent in solution, but are highly fluorescent in cold matrices, upon aggregate formation in poor solvents and in the solid, crystalline state. If aldehyde or dibutylamino groups are attached in the para‐position of the DSB unit, non‐classic AIE‐phores result. These are fluorescent both in dilute solution as well as in the solid state. Prolonged irradiation of the targets leads to benzotetraphene derivatives by a double cyclization. 相似文献
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Dr. Jie Li Dr. Yang Zhang Dr. Ju Mei Dr. Jacky W. Y. Lam Prof. Jianhua Hao Prof. Ben Zhong Tang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(2):907-914
A novel molecular design strategy is provided to rationally tune the stimuli response of luminescent materials with aggregation‐induced emission (AIE) characteristics. A series of new AIE‐active molecules (AIE rotors) are prepared by covalently linking different numbers of tetraphenylethene moieties together. Upon gradually increasing the number of rotatable phenyl rings, the sensitivity of the response of the AIE rotors to viscosity and temperature is significantly enhanced. Although the molecular size is further enlarged, the performance is only slightly improved due to slightly increased effective rotors, but with largely increased rotational barriers. Such molecular engineering and experimental results offer more in‐depth insight into the AIE mechanism, namely, restriction of intramolecular rotations. Notably, through this rational design, the AIE rotor with the largest molecular size turns out to be the most viscosensitive luminogen with a viscosity factor of up to 0.98. 相似文献
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Coordination‐Driven Self‐Assembly of Carbazole‐Based Metallodendrimers with Generation‐Dependent Aggregation‐Induced Emission Behavior 下载免费PDF全文
Wen‐Jia Fan Bin Sun Jianqiu Ma Prof. Dr. Xiaopeng Li Prof. Dr. Hongwei Tan Prof. Dr. Lin Xu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(37):12947-12959
A new family of 120° carbazole‐based dendritic donors D1 – D3 have been successfully designed and synthesized, from which a series of novel supramolecular carbazole‐based metallodendrimers with well‐defined shapes and sizes were successfully prepared by [2+2] and [3+3] coordination‐driven self‐assembly. The structures of newly designed rhomboidal and hexagonal metallodendrimers were characterized by multinuclear NMR (1H and 31P) spectroscopy, ESI‐TOF mass spectrometry, FTIR spectroscopy, and the PM6 semiempirical molecular orbital method. The fluorescence emission behavior of ligands D1 – D3 , rhomboidal metallodendrimers R1 – R3 , and hexagonal metallodendrimers H1 – H3 in mixtures of dichloromethane and n‐hexane with different n‐hexane fractions were investigated. The results indicated that D1 – D3 featured typical aggregation‐induced emission (AIE) properties. However, different from ligands D1 – D3 , metallodendrimers R1 – R3 and H1 – H3 presented interesting generation‐dependent AIE properties. Furthermore, evidence for the aggregation of these metallodendrimers was confirmed by a detailed investigation of dynamic light‐scattering, Tyndall effect, and SEM. This research not only provides a highly efficient strategy for constructing carbazole‐based dendrimers with well‐defined shapes and sizes, but also presents a new family of carbazole‐based dendritic ligands and rhomboidal and hexagonal metallodendrimers with interesting AIE properties. 相似文献
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《Macromolecular rapid communications》2017,38(10)
Aggregation‐induced emission (AIE) is an abnormal phenomenon that has sparked great attention for diverse applications in different fields. In particular, the fabrication and biological imaging applications of AIE‐active fluorescent organic nanoparticles (FONs) have become a focus in the emerging and promising fields. A large number of AIE‐active polymeric nanoprobes have recently been fabricated through different strategies. The advances and progress in this direction have also recently been summarized by some groups. However, the fabrication and biomedical applications of AIE‐active FONs based on carbohydrate polymers and AIE‐active dyes are quite rare and limited. In this feature article, the recently reported AIE‐active FONs with different structures and applications based on AIE‐active dyes and carbohydrate polymers are highlighted, and the major current limitations and development tendencies are also discussed.
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Restriction of Intramolecular Motions: The General Mechanism behind Aggregation‐Induced Emission 下载免费PDF全文
Nelson L. C. Leung Dr. Ni Xie Dr. Wangzhang Yuan Dr. Yang Liu Dr. Qunyan Wu Prof. Qian Peng Prof. Qian Miao Dr. Jacky W. Y. Lam Prof. Ben Zhong Tang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(47):15349-15353
Aggregation‐induced emission (AIE) has been harnessed in many systems through the principle of restriction of intramolecular rotations (RIR) based on mechanistic understanding from archetypal AIE molecules such as tetraphenylethene (TPE). However, as the family of AIE‐active molecules grows, the RIR model cannot fully explain some AIE phenomena. Here, we report a broadening of the AIE mechanism through analysis of 10,10′,11,11′‐tetrahydro‐5,5′‐bidibenzo[a,d][7]annulenylidene (THBDBA), and 5,5′‐bidibenzo[a,d][7]annulenylidene (BDBA). Analyses of the computational QM/MM model reveal that the novel mechanism behind the AIE of THBDBA and BDBA is the restriction of intramolecular vibration (RIV). A more generalized mechanistic understanding of AIE results by combining RIR and RIV into the principle of restriction of intramolecular motions (RIM). 相似文献
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An Organic Molecule with Asymmetric Structure Exhibiting Aggregation‐Induced Emission,Delayed Fluorescence,and Mechanoluminescence 下载免费PDF全文
Shidang Xu Dr. Tingting Liu Dr. Yingxiao Mu Dr. Yi‐Fan Wang Prof. Zhenguo Chi Dr. Chang‐Cheng Lo Prof. Siwei Liu Prof. Yi Zhang Dr. Alan Lien Prof. Jiarui Xu 《Angewandte Chemie (International ed. in English)》2015,54(3):874-878
Compounds displaying delayed fluorescence (DF), from severe concentration quenching, have limited applications as nondoped organic light‐emitting diodes and material sciences. As a nondoped fluorescent emitter, aggregation‐induced emission (AIE) materials show high emission efficiency in their aggregated states. Reported herein is an AIE‐active, DF compound in which the molecular interaction is modulated, thereby promoting triplet harvesting in the solid state with a high photoluminescence quantum yield of 93.3 %, which is the highest quantum yield, to the best of our knowledge, for long‐lifetime emitters. Simultaneously, the compound with asymmetric molecular structure exhibited strong mechanoluminescence (ML) without pretreatment in the solid state, thus exploiting a design and synthetic strategy to integrate the features of DF, AIE, and ML into one compound. 相似文献
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Tianxiang Wang Yunbo Cai Zhipeng Wang Erjia Guan Dahai Yu Anjun Qin Jingzhi Sun Ben Zhong Tang Changyou Gao 《Macromolecular rapid communications》2012,33(18):1584-1589
Tetraphenylethylene (TPE)‐substituted poly(allylamine hydrochloride) (PAH‐g‐TPE) is synthesized by a Schiff base reaction between PAH and TPE‐CHO. The PAH‐g‐TPE forms micelles in water at pH 6, which are further transformed into pure TPE‐CHO nanoparticles (NPs) with a diameter of ≈300 nm after incubation in a solution of low pH value. In contrast, only amorphous precipitates are obtained when TPE‐CHO methanol solution is incubated in water. The aggregation‐induced emission feature of the TPE molecule is completely retained in the TPE NPs, which can be internalized into cells and show blue fluorescence. Formation mechanism of the TPE NPs is proposed by taking into account the guidance effect of linear and charged PAH molecules, and the propeller‐stacking manner between the TPE‐CHO molecules. 相似文献
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《Macromolecular rapid communications》2017,38(6)
An extrinsic self‐healing coating system containing tetraphenylethylene (TPE) in microcapsules was monitored by measuring aggregation‐induced emission (AIE). The core healing agent comprised of methacryloxypropyl‐terminated polydimethylsiloxane, styrene, benzoin isobutyl ether, and TPE was encapsulated in a urea‐formaldehyde shell. The photoluminescence of the healing agent in the microcapsules was measured that the blue emission intensity dramatically increased and the storage modulus also increased up to 105 Pa after the photocuring. These results suggested that this formulation might be useful as a self‐healing material and as an indicator of the self‐healing process due to the dramatic change in fluorescence during photocuring. To examine the ability of the healing agent to repair damage to a coating, a self‐healing coating containing embedded microcapsules was scribed with a razor. As the healing process proceeded, blue light fluorescence emission was observed at the scribed regions. This observation suggested that self‐healing could be monitored using the AIE fluorescence.
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A Fluorogenic Probe with Aggregation‐Induced Emission Characteristics for Carboxylesterase Assay through Formation of Supramolecular Microfibers 下载免费PDF全文
Xiaojing Wang Huan Liu Jingwen Li Kaiguo Ding Zhonglin Lv Prof. Yonggang Yang Prof. Hong Chen Prof. Xinming Li 《化学:亚洲杂志》2014,9(3):784-789
Herein, we report a novel fluorescent “light‐up” probe useful for carboxylesterase assay that is based on a tetraphenylethylene derivative containing carboxylic ester groups. The specific cleavage of the carboxylic ester bonds by carboxylesterase results in the generation of a relatively hydrophobic moiety that self‐assembles into supramolecular microfibers, thus giving rise to “turn‐on” fluorescent signals. A high sensitivity towards carboxylesterase was achieved with a detection limit as low as 29 pM , which is much lower than the corresponding assays based on other fluorescent approaches. 相似文献
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Synthesis and Design of Aggregation‐Induced Emission Surfactants: Direct Observation of Micelle Transitions and Microemulsion Droplets 下载免费PDF全文
Dr. Weijiang Guan Dr. Wenjuan Zhou Prof. Dr. Chao Lu Prof. Dr. Ben Zhong Tang 《Angewandte Chemie (International ed. in English)》2015,54(50):15160-15164
The direct visualization of micelle transitions is a long‐standing challenge owing to the intractable aggregation‐caused quenching of light emission in the micelle solution. Herein, we report the synthesis of a surfactant with a tetraphenylethene (TPE) core and aggregation‐induced emission (AIE) characteristics. The transition processes of surfactant micelles and the microemulsion droplets (MEDs) formed by the surfactant with a TPE core were clearly visualized by a high‐contrast fluorescence imaging method. The fluorescence intensity of the MEDs decreased as the size of MEDs increased as a result of weakening of the restriction of intramolecular rotation (RIR). The results of this study deepen our understanding of micelle‐transition processes and provide solid evidence in favor of the hypothesis that the AIE phenomenon has its origin in the RIR of fluorophores in the aggregate state. 相似文献