Chengyun Wang

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

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Publications (17)26.59 Total impact

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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; · 0.92 Impact Factor
  • Journal of Photochemistry and Photobiology A: Chemistry. 01/2014; 294:54–61.
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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). · 0.92 Impact Factor
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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 01/2013; 127(5). · 1.40 Impact Factor
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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. · 5.97 Impact Factor
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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 01/2012; 30(12). · 0.92 Impact Factor
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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 01/2010; 28(5):699-704. · 0.92 Impact Factor
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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). · 2.97 Impact Factor
  • Journal of Heterocyclic Chemistry 09/2009; 46(5):881 - 885. · 1.22 Impact Factor
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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 01/2009; 27(10):2020-2024. · 0.92 Impact Factor
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    ABSTRACT: Seven lower odor benzophenone (BP) derivatives (2a, 2b, 2c, 2d, 3a, 3b, 3c) based on 4-hydroxybenzophenone(1) were synthesized and characterized by 1H NMR, Mass, UV–Vis absorption spectroscopy. electron spin resonance (ESR) spectroscopy was carried out to research the photopolymerization mechanism. The kinetics of photopolymerization was studied by differential scanning photocalorimetry (photo-DSC). The results showed that 2a–d with uni-BP moiety were more effective photoinitiators (PIs) than 3a–c with bi-BP moieties, and 2c was the most effective one which could be a promising candidate for BP alternative in practical application. Copyright © 2009 John Wiley & Sons, Ltd.
    Polymers for Advanced Technologies 01/2009; · 1.64 Impact Factor
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    ABSTRACT: Two polycarbazoles with tetrathiafulvalene (TTF) as pendant group were synthesized first by Yamamoto coupling reaction using Ni(1,5-cyclooctadiene)2 (Ni(COD)2) as the catalyst. The structures of the polymers and their intermediates were characterized by 1H NMR, 13C NMR, MS, GPC, UV−vis, and IR. The electrochemical behaviors of the polymers were characterized by cyclic voltammetry. These polymers exhibit higher conductivity up to about 0.1 S cm-1.
    Macromolecules. 02/2008; 41(6).
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    ABSTRACT: Three donor–acceptor dyads 1–3 comprising of a tetrathiafulvalene (TTF) unit linked with perylene by a simple σ-bond were synthesized and characterized. Spectroscopy and cyclic voltammetry provided an indication that intramolecular charge-transfer interactions in their ground states between TTF and perylene for dyads 1–3 are negligible. Compared with the compound perylene, dyads 1–3 exhibited large fluorescence quenching, which might be ascribed to photo-induced electron transfer interaction between TTF and perylene units in the excited state.
    Monatshefte fuer Chemie/Chemical Monthly 01/2008; 139(11):1357-1362. · 1.63 Impact Factor
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    ABSTRACT: Two polysilanes with tetrathiafulvalene (TTF) as pendant groups were synthesized by reaction of 2-cyanoethyl substituted TTF1 with (chloromethylphenyl)dimethyl(phenyl)polysilane, or reaction of 4-vinylphenyl-TTF2 with poly[methylsilane-co-methyl(phenyl)silane]. The structures and properties of TTF-polysilanes and their intermediates were characterized by 1H NMR, mass, GPC, UV/Vis, IR and cyclic voltammetry (CV). The results of UV/Vis and CV of these polysilanes indicated interaction between the TTF moieties and σ-electron delocalized Si–Si chain in the ground states. These polysilanes doped by I2 exhibited high conductivities (10−2 S cm−1).
    New Journal of Chemistry 01/2008; 32(3). · 2.97 Impact Factor
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    ABSTRACT: High-speed counter-current chromatography (HSCCC) was applied to preparative separation and purification of dl-tetrahydropalmatine from Corydalis yanhusuo by a one-step separation. The two-phase system consisted of petroleum ether–ethyl acetate–methanol–water (15:30:21:20, v/v) was employed. An orthogonal design was used for optimizing the revolution speed of the separation column, flow rate of the mobile phase and separation temperature, which was 850 rpm, 1.2 ml/min and 20 • C, respectively. HPLC analysis of the fractions collected by preparative HSCCC of 200 mg of crude extracts showed that the purity of dl-tetrahydropalmatine (8.6 mg) was 96.4%. The chemical identity of the component was confirmed by 1 H NMR and EI-MS.
    Separation and Purification Technology 01/2007; · 2.89 Impact Factor
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    ABSTRACT: High-speed counter-current chromatography (HSCCC) was successfully applied to purify ferulic acid from the extracts of Radix Angelicae sinensis, which were extracted by microwave-assisted extraction (MAE). A solvent system consisted of n-hexane–ethyl acetate–methanol–water (3:7:5:5, v/v) was employed. The purity of ferulic acid was over 98% assayed by HPLC. The optimal extraction conditions can be concluded: 850 W of microwave power, 9 min of irradiation time, 90% of ethanol concentration, 6:1 ratio of liquid/solid, 140 min of herbal material soak time and particle sample size 250 ± 9.9 μm, the results showed that microwave-assisted extraction was a promising method for extracting ferulic acid.
    Separation and Purification Technology. 01/2006;
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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 70(1). · 1.33 Impact Factor