Anjun Qin

Zhejiang University, Hang-hsien, Zhejiang Sheng, China

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Publications (142)451.28 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Aggregation-induced emission (AIE) has attracted considerable attention in the research areas of chemo-/biosensors and photo-electronic materials. It is of great significance to develop new AIE materials and to extend their applications. Herein, we report a novel AIE system. It’s AIE activity is triggered by the host-guest recognition interaction between dibenzo[24]crown-8 and protonated secondary amine, in which the recognition units are chemically linked to tetraphenylethene (TPE, a luminogen possessing AIE property, AIE-gen). The host-guest interaction initiated the “polymerization” of the TPE-containing building blocks and turned on the emission of the AIE-gens. The breaking of the non-covalent bonds eliminated the restriction and turned the emission off. The assembling/disassembling processes accompanied by FL turn-on/off have been found to be dynamic, reversible and tunable by treating the system with acid/base.
    Chemical Communications 11/2014; · 6.38 Impact Factor
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    ABSTRACT: An in-depth understanding of dynamic interfacial self-assembly processes is essential for a wide range of topics in theoretical physics, materials design, and biomedical research. However, direct monitoring of such processes is hampered by the poor imaging contrast of a thin interfacial layer. We report in situ imaging technology capable of selectively highlighting self-assembly at the phase boundary in real time by employing the unique photophysical properties of aggregation-induced emission. Its application to the study of breath-figure formation, an immensely useful yet poorly understood phenomenon, provided a mechanistic model supported by direct visualization of all main steps and fully corroborated by simulation and theoretical analysis. This platform is expected to advance the understanding of the dynamic phase-transition phenomena, offer insights into interfacial biological processes, and guide development of novel self-assembly technologies.
    Angewandte Chemie International Edition 10/2014; · 11.34 Impact Factor
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    ABSTRACT: An in-depth understanding of dynamic interfacial self-assembly processes is essential for a wide range of topics in theoretical physics, materials design, and biomedical research. However, direct monitoring of such processes is hampered by the poor imaging contrast of a thin interfacial layer. We report in situ imaging technology capable of selectively highlighting self-assembly at the phase boundary in real time by employing the unique photophysical properties of aggregation-induced emission. Its application to the study of breath-figure formation, an immensely useful yet poorly understood phenomenon, provided a mechanistic model supported by direct visualization of all main steps and fully corroborated by simulation and theoretical analysis. This platform is expected to advance the understanding of the dynamic phase-transition phenomena, offer insights into interfacial biological processes, and guide development of novel self-assembly technologies.
    Angewandte Chemie 10/2014;
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    ABSTRACT: In this work, two tailored luminogens (TPE-NB and TPE-PNPB) consisting of tetraphenylethene (TPE), diphenylamino, and dimesitylboryl as a π-conjugated linkage, electron donor, and electron acceptor, respectively, are synthesized and characterized. Their thermal stabilities, photophysical properties, solvachromism, fluorescence decays, electronic structures, electrochemical behaviors, and electroluminescence (EL) properties are investigated systematically, and the impacts of electron donor-acceptor (D-A) interaction on optoelectronic properties are discussed. Due to the presence of a TPE unit, both luminogens show aggregation-induced emission, but strong D-A interaction causes a decrease in emission efficiency and red-shifts in photoluminescence and EL emissions. The luminogen, TPE-PNPB, with a weak D-A interaction fluoresces strongly in solid film with a high fluorescence quantum yield of 94%. The trilayer OLED [ITO/NPB (60 nm)/TPE-PNPB (20 nm)/TPBi (40 nm)/LiF (1 nm)/Al (100 nm)] utilizing TPE-PNPB as a light emitter shows a peak luminance of 49 993 cd m(-2) and high EL efficiencies up to 15.7 cd A(-1), 12.9 lm W(-1), and 5.12%. The bilayer OLED [ITO/TPE-PNPB (80 nm)/TPBi (40 nm)/LiF (1 nm)/Al (100 nm)] adopting TPE-PNPB as a light emitter and hole transporter simultaneously affords even better EL efficiencies of 16.2 cd A(-1), 14.4 lm W(-1), and 5.35% in ambient air, revealing that TPE-PNPB is an eximious p-type light emitter.
    ACS Applied Materials & Interfaces 09/2014; · 5.90 Impact Factor
  • Anjun Qin, Ben Zhong Tang
    Nature materials. 09/2014; 13(10):917-8.
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    ABSTRACT: The first example of InCl3-catalyzed polycyclotrimerization of diynes to generate regioregular hyperbranched polymers was developed. The InCl3/2-iodophenol-catalyzed polycyclotrimerization of aromatic/aliphatic diynes in chlorobenzene readily furnished soluble 1,3,5-trisubstituted benzene-cored hyperbranched polyarylenes with high weight-averaged molecular weights (up to 37200) in high yields (up to 87.8%). Thanks to its low cost and moisture-tolerance, this catalytic system is anticipated to be widely applied in preparation of regioregular functional hyperbranched polymers with unique properties.
    Polym. Chem. 07/2014;
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    ABSTRACT: Monosaccharide-functionalized poly(phenylacetylenes) (PPAs) are synthesized with high yield and molecular weight, but it shows no solvating power to multiwalled carbon nanotubes (MWCNTs) by simply blending them together. Polymerization of monosaccharide-functionalized monomers in the presence of MWCNTs (in situ polymerization) leads to the hybrids of monosaccharide-functionalized PPAs/MWCNTs and the content of MWCNTs is over 2% by weight. The characterization data indicates that the π–π interaction between the styrene-like moieties in the polymer backbone and the MWCNTs plays crucial role in the dispersing capacity. Based on the in situ precipitation method, CS rods containing monosaccharide-functionalized PPAs/MWCNTs hybrids are fabricated. The bending strength and modulus of the hybrid-reinforced CS rods showed substantial improvement in comparison with the CS rods made from pristine and hydroxyapatite-reinforced CS.
    Polym. Chem. 07/2014;
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    ABSTRACT: A novel tetraphenylethene-based fluorescent H2S probe was designed and synthesized, which exhibited high selectivity and tuneable sensitivity, making direct indication of H2S concentration in blood and unknown samples possible.
    Chemical Communications 06/2014; · 6.38 Impact Factor
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    ABSTRACT: Diketopyrrolopyrrole (ACQ-gen) and tetraphenylethenes (AIE-gen) are linked together with phenyl bridges. The derivatives show substantially enhanced and red-shifted emission in the solid state.
    Chemical Communications 06/2014; · 6.38 Impact Factor
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    ABSTRACT: “United we stand, divided we fall.”–Aesop.Aggregation-induced emission (AIE) refers to a photophysical phenomenon shown by a group of luminogenic materials that are non-emissive when they are dissolved in good solvents as molecules but become highly luminescent when they are clustered in poor solvents or solid state as aggregates. In this Review we summarize the recent progresses made in the area of AIE research. We conduct mechanistic analyses of the AIE processes, unify the restriction of intramolecular motions (RIM) as the main cause for the AIE effects, and derive RIM-based molecular engineering strategies for the design of new AIE luminogens (AIEgens). Typical examples of the newly developed AIEgens and their high-tech applications as optoelectronic materials, chemical sensors and biomedical probes are presented and discussed.
    Advanced Materials 06/2014; · 14.83 Impact Factor
  • Macromolecular Chemistry and Physics 04/2014; · 2.39 Impact Factor
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    ABSTRACT: Incorporation of polycyclic aromatic hydrocarbons into siloles enhances their light emission in solutions but lowers emission efficiency in the aggregated state. The competitive interaction between conjugation and rotation is thus studied.
    Chemical Communications 03/2014; · 6.38 Impact Factor
  • The Analyst 03/2014; · 4.23 Impact Factor
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    ABSTRACT: A tetraphenylethene (TPE) derivative substituted with the electron-acceptor 1,3-indandione (IND) group was designed and prepared. The targeted IND-TPE reserves the intrinsic aggregation-induced emission (AIE) property of the TPE moiety. Meanwhile, owing to the decorated IND moiety, IND-TPE demonstrates intramolecular charge-transfer process and pronounced solvatochromic behavior. When the solvent is changed from apolar toluene to highly polar acetonitrile, the emission peak redshifts from 543 to 597 nm. IND-TPE solid samples show an evident mechanochromic process. Grinding of the as-prepared powder sample induces a redshift of emission from green (peak at 515 nm) to orange (peak at 570 nm). The mechanochromic process is reversible in multiple grinding–thermal annealing and grinding–solvent-fuming cycles, and the emission of the solid sample switches between orange (ground) and yellow (thermal/solvent-fuming-treated) colors. The mechanochromism is ascribed to the phase transition between amorphous and crystalline states. IND-TPE undergoes a hydrolysis reaction in basic aqueous solution, thus the red-orange emission can be quenched by OH− or other species that can induce the generation of sufficient OH−. Accordingly, IND-TPE has been used to discriminatively detect arginine and lysine from other amino acids, due to their basic nature. The experimental data are satisfactory. Moreover, the hydrolyzation product of IND-TPE is weakly emissive in the resultant mixture but becomes highly blue-emissive after the illumination for a period by UV light. Thus IND-TPE can be used as a dual-responsive fluorescent probe, which may extend the application of TPE-based molecular probes in chemical and biological categories.
    Chemistry 03/2014; · 5.93 Impact Factor
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    ABSTRACT: Aggregation-induced emission (AIE) and aggregation-enhanced emission (AEE) have recently been a hot research topic. Currently, efforts have been mostly made on low mass molecules. Their structure–property relationship has been well-established but no work on polymers has been reported, probably due to the harsh reaction conditions for most of the polymerization processes. We used the powerful and facile Cu(I)-catalysed click polymerization in this paper to synthesize four polytriazoles with small variation in either the backbones or the linking manner of the triazole. The results show that changing the hydrogen groups of the stilbene units of P3b and P6b to the phenyl rings of the tetraphenylethene moieties of P3a and P6a readily leads to distinctive differences in their photophysical properties. P3a and P6a are AEE-active, while P3b and P6b display a typical aggregation-caused quenching effect. Meanwhile, investigation on the linking manner of 1,4-positions of the triazole ring indicates that this variation exerts little influence on the emission properties. This work could thus serve as a guideline for the further design of luminogenic polymers for high-tech applications.
    Polymer Chemistry 03/2014; 5(7). · 5.23 Impact Factor
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    ABSTRACT: Two disubstituted acetylenes bearing a vinyl group at one end (M1 and M2) were synthesized and polymerized by WCl6–Ph4Sn catalyst. The expected poly(disubstituted acetylenes) PDSAs (P1 and P2) were obtained in high yields. Both P1 and P2 have reactive vinyl groups on their side chains, thus they were used as precursors to be subsequently modified with a mercapto compound through the thiol–ene click reaction to produce the novel PDSAs (P1S and P2S) in good yield. The chemical structures of the polymers were carefully characterized by standard spectroscopic methods such as gel permeation chromatography (GPC), NMR, NMR and FTIR techniques, and satisfactory data were collected. The post-polymerization modification of P1 took a long reaction time (3 days) to convert P1 to P1S because the ene-functionality at the end of side chain of P1 links to a saturated alkyl segment. By using an activated ene-functionality (a,ß-unsaturated vinyl), the modification of P2 to P2S took only 1 day under mild conditions. Moreover, the activated end-ene group allowed the post-polymerization modification of P2 by Michael addition, which was confirmed using butylamine as the representative amine compound and the characterization data indicated the validity of the expected P2N. The thermal analysis results indicated that the modified polymers were highly stable thermally with a decomposition temperature over at least 240 °C, except for P2N, which showed lower stability due to unstable imine groups. Meanwhile, it was found that the modified polymers P1S and P2S were fluorescent and showed similar emission efficiency to their precursors P1 and P2. These results indicated that the thiol–ene click reaction and Michael addition reaction are accessible routes for post-polymerization modification to generate novel functional PDSAs.
    Polym. Chem. 03/2014; 5(7).
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    ABSTRACT: 2,3,4,5-Tetraphenylsiloles are excellent solid-state light emitters featured aggregation-induced emission (AIE) characteristics, but those that can efficiently function as both light-emitting and electron-transporting layers in one organic light-emitting diode (OLED) are much rare. To address this issue, herein, three tailored n-type light emitters comprised of 2,3,4,5-tetraphenylsilole and dimesitylboryl functional groups are designed and synthesized. The new siloles are fully characterized by standard spectroscopic and crystallographic methods with satisfactory results. Their thermal stabilities, electronic structures, photophysical properties, electrochemical behaviors and applications in OLEDs are investigated. These new siloles exhibit AIE characteristics with high emission efficiencies in solid films, and possess lower LUMO energy levels than their parents, 2,3,4,5-tetraphenylsiloles. The double-layer OLEDs [ITO/NPB (60 nm)/silole (60 nm)/LiF (1 nm)/Al (100 nm)] fabricated by adopting the new siloles as both light emitter and electron transporter afford excellent performances, with high electroluminescence efficiencies up to 13.9 cd A–1, 4.35% and 11.6 lm W–1, which are increased greatly relative to those attained from the triple-layer devices with an additional electron-transporting layer. These results demonstrate effective access to n-type solid-state emissive materials with practical utility.
    Advanced Functional Materials 03/2014; · 10.44 Impact Factor
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    ABSTRACT: The “thio-click” polymerization is a well-expanded concept of click polymerization. Among the click polymerizations, the thiol–yne click polymerization is less developed and still in its infancy stage. In general, UV light, elevated temperature, amine, or transition metal complexes is needed to catalyze the thiol–yne click polymerization, which greatly complicates the experimental operation and limits its application. In this work, a facile and powerful thiol–yne click polymerization was developed, which could be carried out under very mild conditions without using external catalyst. Simply mixing the aromatic diynes (1a–1e) and dithiols (2–4) with equivalent molar ratio in THF at 30 °C will readily produce soluble and regioregular functional poly(vinylene sulfide)s (PIa–PIe, PII, and PIII) with high molecular weights (Mw up to 85 200) in excellent yields (up to 97%) after as short as 2 h. Furthermore, no double addition product of an ethynyl group was found. This catalyst-free thiol–yne click polymerization has remarkably simplified the reaction conditions and will facilitate the preparation of functional materials applied in diverse areas.
    Macromolecules 02/2014; 47(4):1325–1333. · 5.93 Impact Factor
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    ABSTRACT: 2,3,4,5-Tetraarylsiloles are a class of important luminogenic materials with efficient solid-state emission and excellent electron-transport capacity. However, those exhibiting outstanding electroluminescence properties are still rare. In this work, bulky 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, and 9,9'-spirobifluorenyl substituents were introduced into the 2,5-positions of silole rings. The resulting 2,5-difluorenyl-substituted siloles are thermally stable and have low-lying LUMO energy levels. Crystallographic analysis revealed that intramolecular π-π interactions are prone to form between 9,9'-spirobifluorene units and phenyl rings at the 3,4-positions of the silole ring. In the solution state, these new siloles show weak blue and green emission bands, arising from the fluorenyl groups and silole rings with a certain extension of π conjugation, respectively. With increasing substituent volume, intramolecular rotation is decreased, and thus the emissions of the present siloles gradually improved and they showed higher fluorescence quantum yields (ΦF =2.5-5.4 %) than 2,3,4,5-tetraphenylsiloles. They are highly emissive in solid films, with dominant green to yellow emissions and good solid-state ΦF values (75-88 %). Efficient organic light-emitting diodes were fabricated by adopting them as host emitters and gave high luminance, current efficiency, and power efficiency of up to 44 100 cd m(-2) , 18.3 cd A(-1) , and 15.7 lm W(-1) , respectively. Notably, a maximum external quantum efficiency of 5.5 % was achieved in an optimized device.
    Chemistry 01/2014; · 5.93 Impact Factor
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    ABSTRACT: Bioimaging systems with cytocompatibility, photostability, red fluorescence, and optical nonlinearity are in great demand. Herein we report such a bioimaging system. Integration of tetraphenylethene (T), triphenylamine (T), and fumaronitrile (F) units yielded adduct TTF with aggregation-induced emission (AIE). Nanodots of the AIE fluorogen with efficient red emission were fabricated by encapsulating TTF with phospholipid. The AIE dots enabled three-dimensional dynamic imaging with high resolution in blood vessels of mouse brain under two-photon excitation.
    Scientific Reports 01/2014; 4:4279. · 5.08 Impact Factor

Publication Stats

773 Citations
451.28 Total Impact Points

Institutions

  • 2006–2014
    • Zhejiang University
      • Department of Polymer Science and Engineering
      Hang-hsien, Zhejiang Sheng, China
    • Shanxi University
      • School of Chemistry and Chemical Engineering
      Taiyuan, Shanxi Sheng, China
  • 2013
    • South China University of Technology
      Shengcheng, Guangdong, China
    • Hangzhou Normal University
      • College of Material, Chemistry and Chemical Engineering
      Hang-hsien, Zhejiang Sheng, China
  • 2005–2013
    • The Hong Kong University of Science and Technology
      • • Department of Chemistry
      • • State Key Laboratory of Molecular Neuroscience
      Chiu-lung, Kowloon City, Hong Kong
    • Technical Institute of Physics and Chemistry
      Peping, Beijing, China
  • 2003–2011
    • Northeast Institute of Geography and Agroecology
      • • Key Laboratory of Organic Solids
      • • Graduate School
      Beijing, Beijing Shi, China
  • 2005–2007
    • Wuhan University
      • Department of Chemistry
      Wuhan, Hubei, China
  • 2003–2005
    • Chinese Academy of Sciences
      • Key Laboratory of Organic Solids
      Peping, Beijing, China