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1.
《Tetrahedron》2019,75(36):130489
An aggregation-induced emission (AIE)-active fluorescent chemosensor based on a tetraphenylethene (TPE) unit has been successfully designed and synthesized. Interestingly, the luminogen could detect Zn2+ selectively in a THF solution with the detection limit of 1.24 × 10−6 mol L−1. Meanwhile, the luminogen could also detect Hg2+ selectively in a THF-water mixture with the water content of 90%, and the detection limit was 2.55 × 10−9 mol L−1. Furthermore, the solid-state mechanochromic fluorescence behavior of the luminogen was investigated systematically. Indeed, the AIE-active luminogen also exhibited reversible mechanofluorochromic phenomenon involving fluorescent color change from blue to green, and powder X-ray diffraction results indicated that the switchable morphology conversion between crystalline and amorphous states was responsible for this mechanochromism phenomenon. 相似文献
2.
A novel tetraphenylethene derivative with a rhodamine unit was successfully synthesized via high-efficiency Suzuki coupling reaction. The highly solid-state emissive target fluorescent molecule exhibited significative aggregation-induced emission enhancement (AIEE) feature. Furthermore, the luminogen showed reversible mechanochromic luminescence behavior involving color change from orange to red. In addition, the powder X-ray diffraction (XRD) test results verified that the mechanofluorochromic phenomenon of luminogen 1 was attributed to a morphological transformation between the crystalline and amorphous states. 相似文献
3.
Diao Y Whaley KE Helgeson ME Woldeyes MA Doyle PS Myerson AS Hatton TA Trout BL 《Journal of the American Chemical Society》2012,134(1):673-684
Although nanoporous materials have been explored for controlling crystallization of polymorphs in recent years, polymorphism in confined environments is still poorly understood, particularly from a kinetic perspective, and the role of the local structure of the substrate has largely been neglected. Herein, we report the use of a novel material, polymer microgels with tunable microstructure, for controlling polymorph crystallization from solution and for investigating systematically the effects of nanoconfinement and interfacial interactions on polymorphic outcomes. We show that the polymer microgels can improve polymorph selectivity significantly. The polymorphic outcomes correlate strongly with the gel-induced nucleation kinetics and are very sensitive to both the polymer microstructure and the chemical composition. Further mechanistic investigations suggest that the nucleation-templating effect and the spatial confinement imposed by the polymer network may be central to achieving polymorph selectivity. We demonstrate polymer microgels as promising materials for controlling crystal polymorphism. Moreover, our results help advance the fundamental understanding of polymorph crystallization at complex interfaces, particularly in confined environments. 相似文献
4.
Benzothiazolium-functionalized tetraphenylethene: an AIE luminogen with tunable solid-state emission
N Zhao Z Yang JW Lam HH Sung N Xie S Chen H Su M Gao ID Williams KS Wong BZ Tang 《Chemical communications (Cambridge, England)》2012,48(69):8637-8639
Melding a benzothiazolium unit with tetraphenylethene generates a new hemicyanine luminogen with aggregation-induced emission characteristics; the luminogen exhibits crystochromism and its solid-state emission can be repeatedly tuned from yellow or orange to red by grinding-fuming or grinding-heating processes due to the transformation from the crystalline to the amorphous state and vice versa. 相似文献
5.
Crystallization of organic molecules is quite complicated because the crystallization process is governed by weak intermolecular interactions. By exploiting aggregation‐induced emission (AIE), we attempted to realize the selective detection of phase transformation during the evaporative crystallization of hexaphenylsilole (HPS), which shows different fluorescent colors in the amorphous and crystalline phases. No fluorescence emission was observed in the HPS solution immediately after dropping on the glass substrate due to the non‐radiative deactivation induced by intramolecular rotational or vibrational motion, suggesting that HPS exists as a monomer in solution. As time elapsed after dropping, green emission first appeared, which changed to blue after solvent evaporation, because of phase transformation from the amorphous state to the crystalline state. This phenomenon supports not only the two‐step nucleation model involving an intermediate such as a liquid‐like cluster prior to nucleation but also the real‐time detection of Ostwald's rule of stages during evaporative crystallization. 相似文献
6.
Fluorescent imaging techniques have attracted much attention as a powerful tool to realize the visualization of structural and morphological evolution of various materials. However, the traditional fluorescent dyes usually suffered from aggregation‐caused quenching, which severely limits the visualization results. In contrast, aggregation‐induced emission (AIE) molecules with high quantum yields in the condensed state showed great opportunities for imaging techniques. In this feature article, recent progresses in visualization with AIE molecules are discussed. Assembly processes including crystallization, gelation process, and dissipative assembly have been observed. To better study information obtained regarding the processes, visualization during reactions, phase transitions, and molecular motions are successfully presented. Based on these successes, AIE molecules were further applied for phase recognition, macro‐dispersion evaluation, and damage detection. Finally, we also present the outlook and perspectives, in our opinion, for the development of visualization by AIE molecules. 相似文献
7.
Color-tunable, aggregation-induced emission of a butterfly-shaped molecule comprising a pyran skeleton and two cholesteryl wings 总被引:1,自引:0,他引:1
Tong H Hong Y Dong Y Ren Y Häussler M Lam JW Wong KS Tang BZ 《The journal of physical chemistry. B》2007,111(8):2000-2007
A chiral pyran derivative containing two cholesteryl groups (1) is synthesized, and its optical properties are investigated. Whereas the isolated molecule of 1 is virtually nonluminescent in dilute solutions, it becomes highly emissive with a 2 orders of magnitude increase in fluorescence quantum yield upon aggregation in poor solvents or in solid state, showing a novel phenomenon of aggregation-induced emission (AIE). The color and efficiency of the AIE of 1 can be tuned by varying the morphology of its aggregates: photoluminescence of its aggregates formed in a tetrahydrofuran/water mixture progressively red-shifts (green --> yellow --> red) with increasing water content of the mixture, with the crystalline aggregates emitting bluer lights in higher efficiencies than their amorphous counterparts. 相似文献
8.
Kenta Kokado Kazuki Sada 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(26):8724-8731
Aggregation‐induced emission (AIE) is a photoluminescence phenomenon in which an AIE luminogen (AIEgen) exhibits intense emission in the aggregated or solid state but only weak or no emission in the solution state. Understanding the mechanism of AIE requires consideration of excited state molecular geometry (for example, a π twist). This Minireview examines the history of AIEgens with a focus on the representative AIEgen, tetraphenylethylene (TPE). The mechanisms of solution‐state quenching are reviewed and the crucial role of excited‐state molecular transformations for AIE is discussed. Finally, recent progress in understanding the relationship between excited state molecular transformations and AIE is overviewed for a range of different AIEgens. 相似文献
9.
Nickel(II) bisimidazolate is polymorphic. Depending on the synthetic strategy adopted, two crystalline phases (alpha- and beta-Ni(im)(2)) or an amorphous material of the same composition can be prepared. The thermodynamically stable alpha-Ni(im)(2) phase, which can be prepared in water at elevated temperatures, contains a two-dimensional polymer (of nearly square meshes) with square-planar NiN(4) chromophores and exo-bidentate imidazolate ligands bridging nickel atoms that are ca. 5.73 A apart. The beta-Ni(im)(2) phase can be kinetically stabilized at lower temperatures, but the structural complexity and the lack of single crystals prevented its full structural characterization, even in the presence of an indexed powder diffraction pattern. The spectroscopic features of these crystalline phases are compared with those of the amorphous material. 相似文献
10.
Dr. Jian-Gang Yu Dr. Li-Ying Sun Chong Wang Yang Li Prof. Ying-Feng Han 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(5):1556-1575
Thanks to the potential of aggregation-induced emission (AIE) phenomena, improved stabilities, and the good selectivity and sensitivity of the chemical responses exhibited by the products, coordination-driven self-assembly with tetraphenylethylene (TPE) units has recently received much attention and has been widely investigated for application in chemical sensors, cell imaging agents, light-harvesting systems, and others. Several reviews have emerged on the topics of AIE chemistry and aggregation-induced emission luminogen (AIEgen)-based supramolecular assembles, however, there is still a distinct lack of full overviews of emission enhancement from the viewpoint of metal-coordination effects. Thus, this minireview offers recent advances that have been made in the design and application of TPE-based metallacycles, metallacages, metal-organic frameworks (MOFs) and coordination polymers (CPs). 相似文献
11.
Three tetraphenylethene-based compounds with different substituents were successfully synthesized. All these fluorescent molecules exhibited typical aggregation-induced emission (AIE) effect. In addition, these luminogens showed various mechanochromic luminescence phenomena. Moreover, the mechanofluorochromic behavior of luminogen 1 was self-reversible. 相似文献
12.
W. P. Weglarz H. Peemoeller A. Rudin 《Journal of Polymer Science.Polymer Physics》2000,38(19):2487-2506
Two‐dimensional time‐domain 1H NMR was used to investigate annealed isotactic polypropylene in the solid phase. The spin–lattice relaxation in the laboratory frame and in the rotating frame were correlated with the shape of the free induction decay to identify and characterize relaxation components over the temperature range −120 to 120 °C. Several phase transitions were observed, and three distinct solid phases, with different chain mobilities, were detected. Two of these phases were identified as regions with different mobilities within the crystalline phase. The third phase was characterized by a high degree of isotropy in molecular motion. This phase, identified as the amorphous phase, appeared as the polymer was heated above a low‐temperature (−45 °C) phase transition. All transitions observed at higher temperatures occurred exclusively in this phase. About one‐third of the polymer chains reside between crystalline lamellae, whereas the majority form amorphous regions outside fibrils of multilamellar structure. Furthermore, the glass‐to‐rubber transition, occurring above −15 °C, consists of three stages. During the first stage, between −15 °C and 15 °C, regions with an increased segment mobility (labeled intermediate phase) appear gradually within the amorphous phase. At 15 °C, the intermediate phase consists of ∼10% of the polymer units, or one‐third of the polymer units constituting the amorphous phase. Between 15 °C and 25 °C, the intermediate phase increases rapidly to 18%. This is associated with the appearance of semiliquid and liquid regions, likely within the intermediate phase. Polymer chain segments (and possibly entire chains) involved in the liquidlike phases exhibit heterogeneous molecular motion with a correlation frequency higher than 106 Hz. These two stages of glass‐to‐rubber transition occur within amorphous regions outside multilamellar structures. The third stage of the glass transition, appearing above 70 °C, is associated with the upper glass transition and occurs within the interlamellar amorphous phase. Finally, on a timescale of 100 ms or less, spin diffusion does not couple the amorphous regions outside fibrils with crystalline and amorphous regions within multilamellar fibrils. However, on a timescale of hundreds of milliseconds to seconds, all different regions within isotactic polypropylene are partially coupled. It is proposed that the relative magnitude of the crystalline magnetization, as observed in the T1ρ experiment, is a good measure of polymer crystallinity. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2487–2506, 2000 相似文献
13.
Yun Lv Prof. Dr. Yang Liu Dan Guo Xin Ye Guangfeng Liu Prof. Dr. Xutang Tao 《化学:亚洲杂志》2014,9(10):2885-2890
It has been reported several times that some organic luminogens with aggregation‐induced emission (AIE) characteristics exhibit the abnormal phenomenon of crystallization‐induced blueshift fluorescence, which makes them suitable for utilization as luminescence color‐switching materials. Because of the attractive application potential and the numerous underlying structure–property relationships in such materials, we investigated a series of fluorenyl‐containing tetrasubstituted ethylenes for their novel optical properties and structural features. The dyes show morphology‐dependent luminescence. Their emission color can be switched between green and blue by means of mechanical grinding and solvent fuming. The transformation between crystalline and amorphous accounts for the luminescence changing. Through single‐crystal and X‐ray diffraction (XRD) analysis, the twisted molecular geometries and loose packing motifs in the crystalline samples are believed to be the intrinsic origin of the external‐stimuli‐induced structural transformation. 相似文献
14.
Mechanofluorochromic Materials Based on Aggregation‐Induced Emission‐Active Boron Ketoiminates: Regulation of the Direction of the Emission Color Changes
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Dr. Ryousuke Yoshii Kazumasa Suenaga Dr. Kazuo Tanaka Prof. Yoshiki Chujo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(19):7231-7237
We report a series of mechanofluorochromic (MFC) compounds based on organoboron complexes with aggregation‐induced emission (AIE) characteristics. We synthesized a variety of boron ketoiminates and investigated the effect of the substituents on the optical properties by altering the end groups in the compounds. The synthesized boron ketoiminates showed AIE properties and MFC behavior. Interestingly, the hypsochromic and bathochromic shifts of the emission bands individually observed for boron ketoiminates depended on the chemical structures of the end groups. From the X‐ray diffraction and differential scanning calorimetry analyses, it was confirmed that the MFC property of boron ketoiminates should be derived from a phase transition between crystalline and amorphous states. In addition, the direction of the peak shifts of the emission bands was controlled by the degree of steric hindrance of the end group. 相似文献
15.
Hojeong Park Guangle Niu Chao Wu Chungwon Park Haixiang Liu Hyokeun Park Ryan T. K. Kwok Jing Zhang Benzhao He Ben Zhong Tang 《Chemical science》2022,13(10):2965
Tracking mitochondrial movement in neurons is an attractive but challenging research field as dysregulation of mitochondrial motion is associated with multiple neurological diseases. To realize accurate and long-term tracking of mitochondria in neurons, we elaborately designed a novel aggregation-induced emission (AIE)-active luminogen, TPAP-C5-yne, where we selected a cationic pyridinium moiety to target mitochondria and employed an activated alkyne terminus to achieve long-term tracking through bioconjugation with amines on mitochondria. For the first time, we successfully achieved the accurate analysis of the motion of a single mitochondrion in live primary hippocampal neurons and the long-term tracking of mitochondria for up to a week in live neurons. Therefore, this new AIEgen can be used as a potential tool to study the transport of mitochondria in live neurons.A novel bioconjugatable and photostable AIE luminogen has been rationally synthesized for precise and long-term tracking of neuron mitochondria. 相似文献
16.
Bo-Wen Wang Kai Jiang Dr. Jian-Xiao Li Dr. Shi-He Luo Prof. Dr. Zhao-Yang Wang Prof. Dr. Huan-Feng Jiang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(6):2358-2363
An efficient and readily scalable thioetherification between 1,1-diphenylethene (DPE) and sodium arylsulfinate was developed for the synthesis of 1,1-diphenylvinylsulfide (DPVS) with the yield up to 99 %. The photophysical properties of DPVS show that the introduction of arylsulfenyl groups onto the parent molecule DPE makes DPVS a novel type of aggregation-induced emission (AIE) luminogen (AIEgen) with large Stoke's shift (up to 188 nm). These DPVS possess AIE properties due to restriction of intramolecular motions (RIM), as demonstrated by crystal structure analysis. Importantly, the AIE performance of DPVS can be applied to sense the nitroaromatic explosive picric acid in aqueous systems through a “turn-off” response. 相似文献
17.
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
18.
Bo‐Wen Wang Kai Jiang Jian‐Xiao Li Shi‐He Luo Zhao‐Yang Wang Huan‐Feng Jiang 《Angewandte Chemie (International ed. in English)》2020,59(6):2338-2343
An efficient and readily scalable thioetherification between 1,1‐diphenylethene (DPE) and sodium arylsulfinate was developed for the synthesis of 1,1‐diphenylvinylsulfide (DPVS) with the yield up to 99 %. The photophysical properties of DPVS show that the introduction of arylsulfenyl groups onto the parent molecule DPE makes DPVS a novel type of aggregation‐induced emission (AIE) luminogen (AIEgen) with large Stoke's shift (up to 188 nm). These DPVS possess AIE properties due to restriction of intramolecular motions (RIM), as demonstrated by crystal structure analysis. Importantly, the AIE performance of DPVS can be applied to sense the nitroaromatic explosive picric acid in aqueous systems through a “turn‐off” response. 相似文献
19.
Qiyao Li Junyi Gong Ying Li Ruoyao Zhang Haoran Wang Jianquan Zhang He Yan Jacky W. Y. Lam Herman H. Y. Sung Ian D. Williams Ryan T. K. Kwok Min-Hui Li Jianguo Wang Ben Zhong Tang 《Chemical science》2021,12(2):709
Developing versatile synthetic methodologies with merits of simplicity, efficiency, and environment friendliness for five-membered heterocycles is of incredible importance to pharmaceutical and material science, as well as a huge challenge to synthetic chemistry. Herein, an unexpected regioselective photoreaction to construct a fused five-membered azaheterocycle with an aggregation-induced emission (AIE) characteristic is developed under mild conditions. The formation of the five-membered ring is both thermodynamically and kinetically favored, as justified by theoretical calculation and experimental evidence. Markedly, a light-driven amplification strategy is proposed and applied in selective mitochondria-targeted cancer cell recognition and fluorescent photopattern fabrication with improved resolution. The work not only delivers the first report on efficiently generating a fused five-membered azaheterocyclic AIE luminogen under mild conditions via photoreaction, but also offers deep insight into the essence of the photosynthesis of fused five-membered azaheterocyclic compounds.A multifunctional, AIE-based, fused five-membered azaheterocycle is photogenerated with light-driven amplification to combat the photobleaching issue and fabricate display materials. 相似文献
20.
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