Anjun Qin

South China University of Technology, Shengcheng, Guangdong, China

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Publications (186)890.38 Total impact

  • Ming CHEN · JingZhi SUN · AnJun QIN · BenZhong TANG

    No preview · Article · Jan 2016 · Chinese Journal
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    ABSTRACT: A series of thermoresponsive AIE polymers were synthesized through the free radical copolymerization of the thermosensitive N-isopropylacrylamide (NIPAM) monomer, the regulative oligo(ethylene glycol) methacrylate (OEGMA) monomer or methyl methacrylate (MMA) monomer, and the fluorescent tetraphenylethene monomer. By adjusting the loading ratio of NIPAM and OEGMA/MMA, the hydrophilicity of the copolymers can be fine-tuned, which enables further modulation of the lower critical solution temperature (LCST) as well as the detection temperature range. Below the LCST, hydrogen bonds are formed between the polymer chain and water molecules, which leads to good solubility and weak emission of the polymers. Above the LCST, interchain or intrachain hydrogen bonds within polymers are favored to form emissive polymer aggregates.
    Full-text · Article · Dec 2015 · Journal of Materials Chemistry C
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    ABSTRACT: 2,3,4,5-Tetraarylsiloles are efficient solid-state luminescent materials with good electron-transporting ability. Substitution at the 2,5-positions of silole rings produce various outstanding functional materials that can be used as active layers in organic light-emitting diodes (OLEDs). In this work, two 2,5-dicarbazole-substitued siloles, (2-Cz)2MTPS and (3-Cz)2MTPS, are facilely synthesized and fully characterized. Their thermal, photophysical, electrochemical, and electroluminescent properties are investigated systematically. The results show that these 2,5-dicarbazole-functined siloles are thermally stable and feature aggregation-enhanced emission characteristics with high solid-state photoluminescence efficiencies. Nondoped OLEDs [ITO/N,N′-di(1-naphthyl)-N,N′-diphenyl-benzidine (NPB) (60 nm)/emitter (20 nm)/TPBi (40 nm)/LiF (1 nm)/Al (100 nm)] fabricated by adopting (2-Cz)2MTPS and (3-Cz)2MTPS as light-emitting layers exhibit good performances, with high luminance of 28240 cd m-2 and electroluminescence efficiency of 4.5 cd A-1. © 2015 Society of Photo-Optical Instrumentation Engineers (SPIE).
    No preview · Article · Dec 2015 · Journal of Photonics for Energy
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    ABSTRACT: We report synthetic routes to functional poly(disubstituted acetylenes) (PDSAs) through the combination of the activated ester strategy and Cu(i) catalyzed azide-alkyne cycloaddition (CuAAC) reaction. Direct polymerization of a disubstituted acetylene monomer with an end-alkyne group under the catalysis of WCl6-Ph4Sn led to the poly(monosubstituted acetylene) by-product (P1) but not the expected PDSA bearing end-alkyne groups. Protection of the end-alkyne group could lead to the expected product but this route has low efficiency. Using the activated ester functionalized PDSA as a precursor (P0) and propargylamine as the modifier, the end-alkyne groups were easily attached onto the side chains of PDSA (P2). Based on the intermediate, the functional group could be efficiently modified onto the intermediate by reacting with azide containing reagents (using benzyl azide as a model) through the CuAAC click reaction, and finally the triazole functionalized PDSA (P3) was derived. The combination of the activated ester and the CuAAC click reaction strategy bestows the synthetic route with the advantages of high efficiency, mild reaction conditions and potentially plentiful functionalities (due to the versatile azide reagents).
    No preview · Article · Dec 2015 · Polymer Chemistry
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    ABSTRACT: Amines play vital roles in agricultural, pharmaceutical, and food industries, but volatile amine vapors are serious threats to human health. Previously reported fluorescent sensors for amine vapor detection usually suffer from aggregation-caused quenching (ACQ) effect and need to be dispersed in solution or matrix materials. Herein, based on the fluorogen of 2-(2-hydroxyphenyl)quinazolin-4(3H)-one (HPQ) with aggregation-induced emission (AIE) properties, we have developed a fluorescent sensor HPQ-Ac for light-up detection of amine vapors through aminolysis reaction. The portable HPQ-Ac sensor can be easily prepared by directly depositing on filter paper, and it can only light up via exposure to amine vapors among various volatile organic compounds. Taking advantage of its portability and high sensitivity for amine vapors, HPQ-Ac sensor can also be used for food spoilage detection and fluorescent invisible ink.
    No preview · Article · Dec 2015
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    ABSTRACT: A series of pure hydrocarbon fluorophores containing a pair of π-stacked oligo-p-phenylenes have been synthesized and analyzed by NMR and X-ray crystallography. They show good fluorescence in solutions and enhanced fluorescence in the aggregated state. Large Stokes shifts (up to 214 nm) have been achieved in these folded fluorophores in virtue of intramolecular energy transfer, and balanced structural rigidity and flexibility. These folded fluorophores provide perfect models for understanding the energy and charge transfer process in π-stacked systems.
    No preview · Article · Dec 2015 · Organic Letters
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    ABSTRACT: The aggregation-induced emission (AIE) phenomenon is important in organic light-emitting diodes (OLEDs), for it can potentially solve the aggregation-caused quenching problem. However, the performance of AIE fluorophor-based OLEDs (AIE OLEDs) is unsatisfactory, particularly for deep-blue devices (CIEy < 0.15). Here, by enhancing the device engineering, a deep-blue AIE OLED exhibits low voltage (i.e., 2.75 V at 1 cd m-2), high luminance (17 721 cd m-2), high efficiency (4.3 lm W-1), and low efficiency roll-off (3.6 lm W-1 at 1000 cd m-2), which is the best deep-blue AIE OLED. Then, blue AIE fluorophors, for the first time, have been demonstrated to achieve high-performance hybrid white OLEDs (WOLEDs). The two-color WOLEDs exhibit i) stable colors and the highest efficiency among pure-white hybrid WOLEDs (32.0 lm W-1); ii) stable colors, high efficiency, and very low efficiency roll-off; or iii) unprecedented efficiencies at high luminances (i.e., 70.2 cd A-1, 43.4 lm W-1 at 10 000 cd m-2). Moreover, a three-color WOLED exhibits wide correlated color temperatures (10 690-2328 K), which is the first hybrid WOLED showing sunlight-style emission. These findings will open a novel concept that blue AIE fluorophors are promising candidates to develop high-performance hybrid WOLEDs, which have a bright prospect for the future displays and lightings.
    Full-text · Article · Dec 2015 · Advanced Functional Materials
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    ABSTRACT: Aggregation-induced emission (AIE) is a unique photo-physical phenomenon and has become an emerging and hot research area. With the enthusiastic efforts paid by researchers, hundreds of AIE-active luminogens (AIEgens) have been generated but heterocyclic AIEgens are rarely reported. Recently, we enriched the family of AIEgens and reported a pyrazine-based AIEgen of tetraphenylpyrazine (TPP), which could be facilely functionalized by a post-synthetic strategy. In this work, we further expanded the TPP-based AIE system by covalently attaching one, two or four electron-donating triphenylamine moieties to the TPP core via Suzuki coupling, and TPP–TPA, TPP–2TPA and TPP–4TPA were produced, respectively. Thanks to their donor-π-acceptor structures, these luminogens exhibit multi-functional properties, such as excellent thermal stability (up to 504 °C), large molar absorptivity, bright emission in the solid state (quantum yields up to 35.2%), solvatochromism, and high two-photon absorption cross-sections (up to 480 GM). Furthermore, using TPP–TPA as the emitting layer, a triple-layer device was fabricated and a turn-on voltage, maximum luminance, current efficiency, power efficiency, and external quantum efficiency of 3.7 V, 17459 cd m−2, 5.49 cd A−1, 3.18 lm W−1 and 2.88% were realized, respectively. These results indicate a huge potential to develop high-tech applications based on these TPP-based AIEgens.
    No preview · Article · Nov 2015 · Journal of Materials Chemistry C
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    ABSTRACT: Organic light-emitting diodes (OLEDs) based on solution-processable small molecules are attracting intense attention, as such technology combines the merits of low-cost solution processability of polymers and finely defined structural uniformity of small molecules. Small-molecule tetraphenylethene (TPE) derivatives are excellent solid-state light emitters featuring aggregation-induced emission (AIE) characteristics, however those that can be used in solution-processable devices are very rare. To address this issue, herein, a series of novel star-shaped bipolar TPE derivatives are synthesized and characterized. Their thermal stabilities, photophysical properties, electronic structures, electrochemical behaviors, and application in solution-processed OLEDs are investigated systematically. These luminogens exhibit AIE characteristics and excellent fluorescence quantum yields up to 95% in the solid state. Nondoped OLEDs are successfully fabricated through a spin-coating method. The solution-processed OLEDs [ITO (130 nm)/PEDOT:PSS (40 nm)/emitter (70 nm)/TPBi (30 nm)/Ba (4 nm)/Al (120 nm)] adopting star-shaped TPE derivatives as light-emitting layers show peak luminance of 11665 cd m−2 and high electroluminescence (EL) efficiencies up to 8.3 cd A−1, 2.6% and 7.5 lm W−1. These results demonstrate a promising avenue towards efficient nondoped OLEDs based on solution-processable AIE-active small molecules.
    No preview · Article · Nov 2015 · Journal of Materials Chemistry C
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    ABSTRACT: Multifunctional hyperbranched polymers have found wide applications in diverse areas. However, the preparation of these polymers is generally under harsh polymerization conditions with limited reactions. In this work, we prepared multifunctional hyperbranched poly(vinylene sulfide)s (hb-PVSs) by our established efficient and spontaneous thiol-yne click polymerization for the first time. A series of hb-PVSs with high molecular weights (Mw up to 63100) were obtained in high yields (up to 86%) from the polymerizations of monomers 1 and 2 with equivalent molar ratio in THF at 20 °C for 2 h. All the hb-PVSs are regioregular, soluble, and thermally stable. Thanks to the unreacted ethynyl groups on their peripheries, the hb-PVSs could be facilely functionalized by consecutive thiol-yne click reactions. Moreover, the solid films of hb-PVSs exhibit higher refractive index (RI) values (n > 1.64) than those of traditional optical plastics. The TPE-containing hb-PVS shows unique aggregation-enhanced emission characteristic and its aggregates could be used to detect explosives with superamplification effect. Therefore, this work not only proves the universality of our developed spontaneous thiol-yne click polymerization but also provides a powerful and versatile platform for the preparation of multifunctional sulfur-containing polymers.
    No preview · Article · Oct 2015 · Macromolecules
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    ABSTRACT: Sulfur-containing polymers have been widely studied because of their high refractivity and low dispersion, but the efficient synthetic approach of them is quite limited. In this work, we use the abundantly existed elemental sulfur as monomer to prepare polythioamide directly and efficiently through a facile multicomponent polymerization (MCP) of aromatic diynes, sulfur, and aliphatic diamines. This MCP can proceed smoothly in a catalyst-free manner with high atom utilization to afford polythioamide with well-defined structure, high molecular weight, and high yield. It demonstrates a convenient approach to convert elemental sulfur into functional polythioamide. Fluorescence is observed from the polythioamide, despite the absence of typical fluorophores, owing to the "heterodox clusters" composed of a large number of lone-pair-containing electron-rich heteroatoms. The emission maxima and efficiencies of the polymers depend on the formation of molecular aggregates through intrachain and intermolecular interactions such as hydrogen bonding and n → π∗ interaction between thioamides. This polymerization is anticipated to accelerate the development of efficient and economic MCPs toward functional polymer materials.
    No preview · Article · Oct 2015 · Macromolecules
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    ABSTRACT: Aggregation-induced emission (AIE) is commonly observed for propeller-like luminogens with aromatic rotors and stators. Herein, we report that a coumarin derivative containing a seven-membered aliphatic ring (CD-7) but no rotors showed typical AIE characteristics, whereas its analogue with a five-membered aliphatic ring (CD-5) exhibited an opposite aggregation-caused quenching (ACQ) effect. Experimental and theoretical results revealed that a large aliphatic ring in CD-7 weakens structural rigidity and promotes out-of-plane twisting of the molecular backbone to drastically accelerate nonradiative excited-state decay, thus resulting in poor emission in solution. The restriction of twisting motion in aggregates blocks the nonradiative decay channels and enables CD-7 to fluoresce strongly. The results also show that AIE is a general phenomenon and not peculiar to propeller-like molecules. The AIE and ACQ effects can be switched readily by the modulation of molecular rigidity.
    No preview · Article · Oct 2015 · Angewandte Chemie International Edition
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    ABSTRACT: An air-stable supported Cu(I) catalyst, CuI@PS-Phen, was designed and synthesized. CuI@PS-Phen can efficiently catalyze the click polymerization of diynes a and diazides b to produce soluble and thermally stable polytriazoles with high molecular weights (M w up to 30800), and low copper residue content (down to 190 ppm) in high yields (up to 94.2%) under mild reaction conditions without the exclusion of oxygen. © 2015 Science China Press and Springer-Verlag Berlin Heidelberg.
    No preview · Article · Sep 2015 · Science China-Chemistry
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    ABSTRACT: Tetra(4-(diethylamino)phenyl)ethene (TPE-4N), a new derivative of tetraphenylethene (TPE), is facilely prepared by one step from bis(4-(diethylamino)phenyl)methanone in a good yield of 85%. TPE-4N shows aggregation-induced emission (AIE) feature with high solid-state fluorescence quantum yields up to 63.5%. It is of strong proton capture capability, allowing for reversible fluorescence switching in acid and basic solutions. A good linear relationship between the emission intensity and the pH value ranging from 4.4 to 6.0 is established. By exposing in hydrochloride vapor, the color of TPE-4N powder is changed from yellow-green to white, accompanied with fluorescence color tuning from green to sky-blue. The resulting protonated luminogen (p-TPE-4N) can be readily reverted to TPE-4N by fuming with hot triethylamine vapor. The protonation and deprotonation progresses are reversible and can be repeated for many times without fatigue in solid state. In addition, p-TPE-4N exhibits reversible thermochromism between 80-120 oC, and reverts to TPE-4N by heating up to 120 oC. The multiple stimuli-responsive and reversible fluorescence indicates TPE-4N is a promising candidate for chemical sensing and environmental monitoring.
    Full-text · Article · Aug 2015
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    ABSTRACT: The cover picture shows efficient organic light-emitting diodes (OLEDs) that are fabricated using a new silole-based luminescent material with aggregation-induced emission (AIE) and good electron-transporting ability. This kind of AIE-active solid-state luminescent materials is of great potential in color displays and white lightning. More details are discussed in the article by Tang et al. on page 842–846.
    No preview · Article · Aug 2015 · Chinese Journal of Chemistry
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    ABSTRACT: A new silole derivative, 2,5-bis(7-(dimesitylboranyl)-9,9-dimethylfluoren-2-yl)-1-methyl-1,3,4-triphenylsilole ((MesBF)2MTPS), is synthesized and characterized. (MesBF)2MTPS shows a good fluorescence efficiency of 15% in THF solution and a higher efficiency of 86% in solid film, presenting an aggregation-enhanced emission characteristic. It is thermally and morphologically stable, with high decomposition and glass-transition temperatures of 257 and 171°C, respectively. The LUMO energy level (−2.96 eV) of (MesBF)2MTPS is lower than that of TPBi, revealing its electron-transporting potential. Efficient organic light-emitting diodes (OLEDs) are fabricated using (MesBF)2MTPS as emitter, which radiates yellow light at 554 nm, and affords high maximum luminance, current efficiency, and external quantum efficiency of 48348 cd·m−2, 12.3 cd·A−1, and 4.1%, respectively.
    No preview · Article · Jun 2015 · Chinese Journal of Chemistry
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    ABSTRACT: N-type pyrazine-based 1,4- and 1,5-disubstituted 1,2,3-triazole derivatives, showing the unique aggregation-enhanced emission characteristics, were facilely prepared by the Cu- and Ru-catalysed azide-alkyne cycloadditions, respectively. Thanks to their electron-deficient property, they could readily form red-emissive charge transfer complexes with electron-donating triphenylamine in the aggregate and solid states.
    Full-text · Article · May 2015 · Chemical Communications
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    ABSTRACT: We present a preliminary study which explores the potential of aggregation-induced emission (AIE) luminogen as a new fluorescent probe for STED microscopy. Compared with Coumarin 102, which is a commonly used organic fluorophore in STED microscopy, HPS, a typical AIE luminogen, is more resistant to photobleaching. In addition, HPS-doped nanoparticles have higher emission depletion efficiency than Coumarin 102 in organic solution. These two advantages of AIE luminogen can facilitate the improvement of spatial resolution, as well as long-term imaging, in STED microscopy. AIE luminogen will be a promising candidate for STED microscopy in the future.
    Full-text · Article · May 2015 · Optics Letters
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    ABSTRACT: The deciphering of structure-property relationships is of high importance to rational design of functional molecules and to explore their potential applications. In this work, a series of silole derivatives substituted with benzo[b]thiophene (BT) at the 2,5-positions of the silole ring are synthesized and characterized. The experimental investigation reveals that the covalent bonding through the 2-position of BT (2-BT) with silole ring allows a better conjugation of the backbone than that achieved though the 5-position of BT (5-BT), and results in totally different emission behaviors. The silole derivatives with 5-BT groups are weakly fluorescent in solutions, but are induced to emit intensely in aggregates, presenting excellent aggregation-induced emission (AIE) characteristics. Those with 2-BT groups can fluoresce more strongly in solutions, but no obvious emission enhancements are found in aggregates, suggesting they are not AIE-active. Theoretical calculations disclose that the good conjugation lowers the rotational motions of BT groups, which enables the molecules to emit more efficiently in solutions. But the well-conjugated planar backbone is prone to form strong intermoelcular interactions in aggregates, which decreases the emission efficiency. Non-doped organic light-emitting diodes (OLEDs) are fabricated by using these siloles as emitters. AIE-active silole derivatives show much better elecroluminescence properties than those without the AIE characterisic, demonstrating the advantage of AIE-active emitters in OLED applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
    No preview · Article · Apr 2015 · Chemistry - A European Journal
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    ABSTRACT: Mechanochromism is a common property of organic solids with aggregation-induced emission (AIE) and aggregation-induced emission enhancement (AIEE) activities. The mechanochromic behaviour is usually reversible for the AIE/AIEE-active compounds, because in these solids the molecules are held together by weak van der Waals interaction. It is the weak van der Waals interaction that allows the switch to be unstable and the memory to be volatile. In principle, the amorphous solid is metastable and destined to enter the most stable crystal state in proper conditions. Therefore, it is a challenging task to delay the spontaneous transition from amorphous to crystal states. Considering that the static attraction between cationic and anionic species is stronger than van der Waals interaction between uncharged species, we introduce ionic pairs into AIEE molecule to enhance the intermolecular interaction and acquire robust mechanochromic effect. Experimental results indicate this molecular design idea is workable by using tetraphenylethene as AIE-luminogen, pyridinium as cation and hexafluorophosphorate as anion, respectively. And the primary success suggest that the rationally designed ionic and organic luminogens are hopeful to achieve the balance between the rigidity of ionic solid and the flexibility of covalent solid.
    Full-text · Article · Apr 2015 · Chemical Communications

Publication Stats

5k Citations
890.38 Total Impact Points

Institutions

  • 2013-2015
    • South China University of Technology
      Shengcheng, Guangdong, China
  • 2007-2015
    • Zhejiang University
      • Department of Polymer Science and Engineering
      Hang-hsien, Zhejiang Sheng, China
  • 2005-2012
    • The Hong Kong University of Science and Technology
      • Department of Chemistry
      Chiu-lung, Kowloon City, Hong Kong
  • 2003-2007
    • Chinese Academy of Sciences
      • Key Laboratory of Organic Solids
      Peping, Beijing, China
  • 2006
    • Northwestern University
      • Department of Chemistry
      Evanston, Illinois, United States
    • Shanxi University
      • School of Chemistry and Chemical Engineering
      Taiyuan, Shanxi Sheng, China
  • 2003-2005
    • Technical Institute of Physics and Chemistry
      Peping, Beijing, China