Chengyun Wang

East China University of Science and Technology, Shanghai, Shanghai Shi, China

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Publications (26)53.9 Total impact

  • Yuwen Ma · Guoqiao Lai · Zhifang Li · Wenbin Tan · Yongjia Shen · Chengyun Wang
  • Rui Huang · Hujin Zuo · Lei Zhang · Chengyun Wang · Yongjia Shen
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    ABSTRACT: Abstract Two copolymers (P1 and P2), bearing 3,4-ethylenedioxythiophene and fluorene moieties, were synthesized via Sonogashira coupling reaction successfully and P2 contains additional tetrathiafulvalene derivatives (TTFs) as pendants. The structures and properties of copolymer P1 and P2 were investigated by Infrared spectra, UV–visible spectra, and fluorescence spectra. Spectra analyses revealed that the fluorescent intensity of P2 was only 2 % compared to that of P1 in solution. The quenched fluorescent intensity of P2 could be recovered after adding defined moles of Fe(ClO4)3 as an oxidant. The phenomenon was discussed with aid of computational stimulation in Gaussian 03. Herein, it is believed that intramolecular charge transfer occurs between TTF pendants and polymeric backbone in P2. P2 could be treated as a reporting group in fluorescent testing/switching system. Graphical abstract
    Polymer Bulletin 06/2015; DOI:10.1007/s00289-015-1418-0 · 1.44 Impact Factor
  • Yingyi Wang · Guoqiao Lai · Zhifang Li · Yuwen Ma · Yongjia Shen · Chengyun Wang
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    ABSTRACT: A series of new A–π–D–π–A molecules including diphenylamine and carbazole had been synthesized and characterized (T1–T3). T1 and T2 displayed aggregation-induced emission enhancement (AIEE): exhibiting weak fluorescence in pure THF, which a signification AIEE effect was observed in mixture with a water fraction (fw) of 90% with a sharp increase in fluorescence intensity. T3 displayed aggregation-caused quenching (ACQ): exhibiting strong fluorescence in pure THF, which a signification ACQ effect was observed in mixture with a water fraction (fw) of 90% with a sharp decrease in fluorescence intensity. Their two-photon absorption (2PA) had been investigated using the open-aperture Z-scan technique, and the values of the 2PA cross section at 800 nm for T1–T3 were 1115, 681, in chloroform, respectively.
    Tetrahedron 05/2015; 71(18). DOI:10.1016/j.tet.2015.03.003 · 2.64 Impact Factor
  • Zhenhua He · Guoqiao Lai · Zhifang Li · Xiao Yuan · Yongjia Shen · Chengyun Wang
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    ABSTRACT: Two copolymers, poly(1,1-dimethyl-3,4-diphenylsilole-alt-N-hexyl-3,6-diethynylcarbazole) (PS-DyCz) and poly(1,1-dimethyl-3,4-diphenylsilole-alt-2,7-diethynyl-9,9′-dihexylfluorene) (PS-DyF), were synthesized by Sonogashira coupling reaction of 2,5-dibromo-1,1-dimethyl-3,4-diphenylsilole and N-hexyl-3,6-diethynylcarbazole or 2,7-diethynyl-9,9′-dihexylfluorene, respectively. The chemical structures of the copolymers were characterized by NMR, FT-IR techniques. Their thermal and photophysical properties were evaluated by TGA, DSC, UV-Vis and fluorescence spectroscopy, respectively. The weight-averaged molecular weights (Mw) of PS-DyCz and PS-DyF are 1.20×104 and 3.83×104 Da, respectively. The degree of polymerization is 8 and 22 units. These π-conjugated polymers exhibited lower band-gap of 2.25 and 2.70 eV due to the presence of silole rings and CC triple bonds in their backbone, the results were consistent with the density functional (DFT) calculations at the B3LYP/6-31G* level.
    Chinese Journal of Chemistry 03/2015; 33(5). DOI:10.1002/cjoc.201400870 · 1.58 Impact Factor
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    ABSTRACT: New donor-linker-acceptor pattern organic dye containing a dithienosilole unit as a pi-conjugated system, a carbazole moiety as an electron donor, and a cyanoacrylic acid unit as an electron acceptor was synthesized for application in dye-sensitized solar cell (DSSC). Its photophysical and electrochemical properties were investigated, the dithienosilole unit could dramatically lower the lowest unoccupied molecular orbital (LUMO) level and energy gap. Its performances as sensitizers in solar cells were measured, and possessed a power conversion efficiency of 4.80%.
    Journal of Photochemistry and Photobiology A Chemistry 11/2014; 294:54–61. DOI:10.1016/j.jphotochem.2014.07.021 · 2.50 Impact Factor
  • Lei Zhang · Changzhi Wu · Chengyun Wang · Hujin Zuo · Yongjia Shen
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    ABSTRACT: 3,4-(Hydroxymethyl-ethylenedioxy)thiophene (4) and 3,4-(2-hydroxypropylenedioxy)thiophene (4') were synthesized from dimethyl 3,4-dihydroxythiophene-2,5-dicarboxylate (1), which were isomers and difficult to separate. When they were esterified with tetrathiafulvalene carried carboxylic acid group, only 3,4-(hydroxymethyl-ethylenedioxy)thiophene (4) could be esterified. No such selectivity was observed when the isomers were esterified by lauric acid and benzoic acid, respectively.
    Journal of Heterocyclic Chemistry 09/2014; 51(5):1277-1281. DOI:10.1002/jhet.1834 · 0.79 Impact Factor
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    ABSTRACT: Reaction between 3,3′-dibromothiophene and sodium methylate/methanol in the presence of KI/CuO afforded 3-bromo-4-methoxythiophene as a major product. It was transformed into 4,4′-dimethoxy-3,3′-bithiophene by using Pd(OAc)2 as a catalyst and agarose as a ligand. The conditions of the reaction were mild with an acceptable yield of 20 %. The product was characterized by MS, 1H NMR, and its spectra of UV–Vis and cyclic voltammetry were given. Graphical Abstract 4,4′-dimethoxy-3,3′-bithiophene was synthesized from 3-bromo-4-methyloxy thiophene in the homogeneous system formed by water and agarose.
    Research on Chemical Intermediates 07/2014; 41(9). DOI:10.1007/s11164-014-1747-x · 1.22 Impact Factor
  • Songyang Jiang · Yuwen Ma · Yingyi Wang · Chengyun Wang · Yongjia Shen
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    ABSTRACT: Two conjugated ethynyl-linked oligomers, oligo(benzodithiophene-ethynylene-benzothiadiazole) (O1) and oligo(benzodithiophene-ethynylene-carbazole) (O2), were synthesized by Sonogashira coupling reaction. Their degrees of polymerization were 7 and 10, respectively. Their photophysical and electrochemical properties were investigated. O1 exhibitd two strong absorption bands at 404 nm and 483 nm, and O2 at 401 nm and 429 nm. The results of UV-Vis, cyclic voltammetry (CV) and theoretical calculations showed that O1 has a narrower band gap than O2. The conductivities of O1 and O2 were 1.05×10−15 and 6.98×10−16 S/cm, respectively, and would increase to 1.23×10−10 and 1.05×10−10 S/cm after doping with iodine.
    Chinese Journal of Chemistry 04/2014; 32(4). DOI:10.1002/cjoc.201400079 · 1.58 Impact Factor
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    ABSTRACT: Two new dye sensitizers 5-(N,N-4-(diphenylamino)phenyl)-10-(4-(tert-butyl-2-cyanoacrylate)phenyl)porphyrin (TP) and 5-(N, N-4-(bis(4-butylphenyl) amino) phenyl)-10-(4-(tert-butyl-2-cyanoacrylate)phenyl)porphyrin (BUTP) with cyanoacrylic acid as electron acceptor were synthesized and researched. BUTP has strong absorption in a wide range of 300–726 nm. DSSCs sensitized by BUTP displayed a power conversion efficiency (η) 5.33%, JSC 12.21 mA cm−2, Voc 0.68 V, FF 0.65, under the illumination of AM 1.5 G. Spectral properties, electrochemical properties, photovoltaic and electrochemical impedance properties of TP and BUTP were also investigated. Considering its simple synthesis, both TP and BUTP were qualified sensitizers for DSSCs.
    Journal of Photochemistry and Photobiology A Chemistry 11/2013; 272:58-64. DOI:10.1016/j.jphotochem.2013.08.010 · 2.50 Impact Factor
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    ABSTRACT: A new conjugated copolymer (PTST-DyOXD) derived from 1,1-dimethyl-3,4-diphenyl-2,5-bis(5-bromo-2-thienyl)-silole (TST) and 2,5-bis(4-ethynylphenyl)-1,3,4-oxadiazole (DyOXD) was synthesized by Pd(0)-catalyzed Sonogashira coupling reaction. For comparison, another copolymer without acetenyl group (PTST-OXD) was also synthesized by Pd(0)-catalyzed Suzuki coupling reaction. Chemical structures and optoelectronic properties of the copolymers were characterized by 1H NMR, 13C NMR, IR, UV-vis absorption, photoluminescence and cyclic voltammetry. The number-average molecular weight (Mn) is 4010 Da for PTST-DyOXD and 3890 Da for PTST-OXD, respectively. The thermogravimetric analysis (TGA) measurements show that they have good thermal stability with decomposition temperature at 312 and 318°C, respectively. The optical band gap is 2.21 eV for PTST-DyOXD and 2.10 eV for PTST-OXD based on the absorption onset. CV analysis revealed the LUMO level of PTST-DyOXD is −3.04 eV, lower than that of PTST-OXD (about −2.89 eV), which is attributed to the introduction of acetylene group in PTST-DyOXD, increasing the system of the conjugate chain length.
    Chinese Journal of Chemistry 06/2013; 31(6). DOI:10.1002/cjoc.201300121 · 1.58 Impact Factor
  • Lei Zhang · Meijiang Li · Chengyun Wang · Yanhong Wang · Yongjia Shen
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    ABSTRACT: Three 3,4‐ethylenedioxythiophene (EDOT) derivatives, including an EDOT‐tetrathiafulvalene (TTF) derivative, were synthesized by Steglich esterification of carboxylic acids with hydroxymethyl EDOT (3,4‐ethylenedioxythiophene methanol). The UV spectra showed that there was no distinctive intramolecular interaction for the EDOT–TTF monomer between the EDOT and the TTF moieties in the ground state; however, the cyclic voltammetry responses implied that such intramolecular interaction occurred. Electropolymerization in excessive potential could bring in strong overoxidation effects and degradation in the polymer film. The polymers were simulated using density functional theory with Gaussian03 package and the optimized HOMO and LUMO state were figured out. The conductivity of TTF‐polymer was 6 S·cm−1 obtained by galvano station and 4.8 × 10−3 S·cm−1 obtained by potentiostatic electropolymerization after doping with 7,7,8,8‐tetracyanoquinodimethane. The results indicated that this polymer was a reasonable candidate for conducting materials and it was meaningful to increase the conductive dimensions of TTF polymers by chemical doping. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
    Journal of Applied Polymer Science 03/2013; 127(5). DOI:10.1002/app.37803 · 1.77 Impact Factor
  • Jie Liu · Chenxu Yan · Shanshan Li · Chengyun Wang · Yongjia Shen
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    ABSTRACT: Three routes were designed to synthesize a π‐conjugated aryleneethynylenesiloles dendron. With the desilylation of the disilole mono(silylethynyl) derivative in the presence of potassium carbonate (K2CO3), the silole‐containing oligomer has been successfully synthesized without impact on the Si‐(CH3)2 group. The disilole mono(silylethynyl) derivative was prepared by means of the Sonogashira heterocoupling reaction between the diacetylene compound and asymmetrical silole, catalyzed by the dichloro bis(triphenylphosphine)palladium, in a divergent synthesis. Due to their steric effect and triethynylbenzene self‐coupling Glaser reaction, the endeavour to prepare the dendron by controlling the molar ratio of asymmetrical silole and 1,3,5‐triethynylbenzene was failed. The another attempt to prepare the dendron by different desilylation condition of triisopropylsilyl group and trimethylsilyl group was also failed, the desilylation of Si‐(CH3)2 group in silacyclopentadiene unit was also easily accomplished in the presence of tetrabutylammonium fluoride(Bu4NF), whereas no reaction occurred when K2CO3 was used instead of Bu4NF.
    Chinese Journal of Chemistry 12/2012; 30(12). DOI:10.1002/cjoc.201200908 · 1.58 Impact Factor
  • Weifu Shu · Changwei Guan · Wenhao Guo · Chengyun Wang · Yongjia Shen
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    ABSTRACT: Hyperbranched and linear conjugated polysiloles incorporating arylene ethynylene subunits (6 and 7) were synthesized by the Sonogashira reaction. The two polymers possess unusual phenomena of PL, with gradual addition of water in their THF solution, the intensity of PL firstly increased and then decreased, this may be due to the aggregate-enhanced emission (AEE) effect and aggregation-caused quenching (ACQ) effect. The polymers function as sensitive fluorescent chemosensors for the detection of explosives, such as picric acid (PA) and TNT. The quenching constants of 6 for PA and TNT were 4.7 × 10−2 ppm−1 and 4.6 × 10−3 ppm−1, respectively. The quenching constants of 7 for PA and TNT were 8.6 × 10−2 ppm−1 and 6.5 × 10−3 ppm−1 respectively. The polymer7 has more detective efficiency for PA and TNT than that of polymer6, this may be due to the less steric hindrance.
    Journal of Materials Chemistry 01/2012; 22(7):3075-3081. DOI:10.1039/C1JM15535K · 7.44 Impact Factor
  • Lei Zhang · Meijiang Li · Chengyun Wang · Guoqiao Lai · Yongjia Shen
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    ABSTRACT: A kind of π-conjugated poly(EDOT-ethynylene-arylene)s P1–P5 were synthesized by Sonogashira coupling reaction between DBEDOT and five arylenes substituted with ethynyl groups. Among them, P5 was a polymer with TTF as pendants. Their TGA results exhibited their good thermal stability and their electrochemical and spectroscopic properties were investigated by CV, UV–Vis, and FL. The results indicated that there were intramolecular interactions between TTF group and polymer backbone as well as between the EDOT and arylene moieties. After doping with TCNQ, P5 could form stable CT-complex with a conductivity of 1.3 × 10−3 S cm−1, while its conductivity could be up to 3.5 × 10−2 S cm−1 after doping with I2, due to its increased conductive dimensions. Such results indicated that this polymer had potential application in developing conducting materials. Graphical Abstract A kind of π-conjugated EDOT-ethynylene-fluorene polymer with TTF as pendants was synthesized, which exhibited good solubility and thermal stability. When doping with I2, its conductivity was improved significantly due to its increased conductive dimensions.
    Polymer Bulletin 01/2012; 70(1). DOI:10.1007/s00289-012-0841-8 · 1.44 Impact Factor
  • Shanshan Li · Taohua Leng · Hanbin Zhong · Chengyun Wang · Yongjia Shen
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    ABSTRACT: Silole-core phenylacetylene dendrimers were designed and synthesized, among them, the model compound (n = 0) and the first generation of the dendrimer (n = 1) were obtained by the reaction of 2,5-dibromosilole with corresponding terminal alkynes, the second generation of the dendrimers (n = 2) was synthesized from 2,5-diiodosilole. These compounds indicated the absorptions of both phenylacetylene dendrons (250–350 nm) and silole core (400–500 nm). The first generation displayed efficient energy transfer from phenylacetylene dendrons to silole core, whose energy transfer efficiency was as high as 80%. These compounds were used as chemical sensors to probe explosive, for picric acid (PA), the Stern–Volmer constants of model compound and the first generation are 7120 and 5490M−1, respectively. J. Heterocyclic Chem., (2012).
    Journal of Heterocyclic Chemistry 01/2012; 49(1):64-70. DOI:10.1002/jhet.796 · 0.79 Impact Factor
  • Chengyun Wang · Hanbin Zhong · Shanshan Li · Weifu Shu · Yongjia Shen
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    ABSTRACT: Phenylacetylene dendrimers 9–11 containing fluorene as the core with a larger HOMO-LUMO energy gap were synthesized and characterized. Their structure and properties were studied by UV, FL, 1H NMR, MS etc. These novel phenylacetylene dendrimers exhibit unique photophysical properties. They exist a new absorption band around 340 nm whose molar coefficient decreases with increasing generation. The band-gaps of 9–11 are 3.54, 3.43 and 3.02 respectively. The fluorescence quantum yield of 10 is as high as 0.61.
    Chinese Journal of Chemistry 05/2010; 28(5):699-704. DOI:10.1002/cjoc.201090134 · 1.58 Impact Factor
  • Xuechao Zhang · Chengyun Wang · Guoqiao Lai · Lei Zhang · Yongjia Shen
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    ABSTRACT: A series of conjugated ethynylene-fluorenepolymers with electro-donating TTF as pendant groups (P2–P4) were synthesized by using Sonogashira coupling reaction, and two functionalization methods, i.e. prepolymerization and postpolymerization, were developed. The composition and purity of the corresponding products were analyzed by 1H NMR. The results proved the functionalization of P2 (pre) and P2 (post) were 40% and 100%, respectively. The results also indicated that the postpolymerization method would be a better approach to prepare TTF-pendant conjugated ethynylene-fluorenepolymers. The postpolymerization methodology could be extended to synthesize other conjugated fluorene-based polymers bearing TTF units (P3 and P4). The polymers mentioned above exhibited good solubility in normal organic solvents and higher conductivity (neutral conductivity 2–4 × 10−6 S cm−1; doped conductivity 1–3 × 10−3 S cm−1). Moreover, the fluorescence intensity of P2 (post) could be modulated by the oxidation of TTF units, which makes it an attractive candidate for the fluorescence switch.
    New Journal of Chemistry 01/2010; 34(2). DOI:10.1039/b9nj00520j · 3.09 Impact Factor
  • Chengyun Wang · Wei Tang · Hanbin Zhong · Xuechao Zhang · Yongjia Shen
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    ABSTRACT: Novel porphyrin-perylene diimide dyad (TPP-PDI) and porphyrin-perylene diimide-porphyrin triad (TPP-PDI-TPP) were synthesized and characterized. Their structure and properties were studied by UV, FL, 1H NMR, MS, elemental analysis, etc. The variation of fluorescence feature and UV spectra of TPP-PDI-TPP triad were investigated at different concentration of CF3COOH in THF. The incorporation of CF3COOH leads to the closure of the efficient charge transfer decay. After protonation of porphyrin units, the fluorescence intensity of TPP-PDI-TPP triad increased greatly. The fluorescence intensity of TPP-PDI-TPP triad restored after addition of triethylamine into the solution. Thus, TPP-PDI-TPP triad was a proton-type fluorescence switch based on acid-base control. Moreover, different from porphyrin-perylene type molecular switches reported before, this TPP-PDI-TPP triad has wonderful solubility in organic solvents.
    Chinese Journal of Chemistry 10/2009; 27(10):2020-2024. DOI:10.1002/cjoc.200990339 · 1.58 Impact Factor
  • Chengyun Wang · Wei Tang · Hanbin Zhong · Xuechao Zhang · Yongjia Shen
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    ABSTRACT: Two highly soluble donor-sigma-acceptor and donor-sigma-accepter-sigma-donor type fluorescence switches consisting tetrathiafulvalene (TTF) and 3,4,9,10-perylene tetracarboxylic diimides (PDI) were synthesized. The structure of the dyad and triad as well as their intermediates was characterized by (1)H NMR, (13)C NMR MS, elemental analysis. Their fluorescence behavior could be modulated by oxidization and reduction of the TTF unit using either chemical or electrochemical method.
    Journal of Heterocyclic Chemistry 09/2009; 46(5):881 - 885. DOI:10.1002/jhet.160 · 0.79 Impact Factor