The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Jinhui Pang - One of the best experts on this subject based on the ideXlab platform.
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poly arylene ether ketone with tetra quaternary ammonium Carbazole Derivative pendant for anion exchange membrane
Polymer, 2020Co-Authors: Kaiqi Wang, Di Liu, Liming Lin, Jinhui PangAbstract:Abstract As a key component of fuel cell, the anion exchange membrane (AEM) must present high durability, which includes dimensional stability，thermal stability，and alkali resistance. In order to obtain AEM with high performance, besides stable structure, the polymer should have high molecular weight and advantaged functional group position. In this work, a novel high molecular weight polymer precursor, poly(arylene ether ketone) (PAEK) with iodobenzene pendent was designed and prepared. And then, the function tetra-quaternary ammonium Carbazole was introduced onto polymer backbone by Ullmann grafting reaction and quaterisation. The obtained membranes exhibited good dimensional stability, appropriate thermal stability and high ion conductivity. In addition, the membranes exhibited good alkaline resistance, as it still kept 90% of the conductivity after immersion in 4M NaOH solution for a week. Over all, the membranes in this work are promising for anion exchange membrane fuel cell.
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poly arylene ether ketone with tetra quaternary ammonium Carbazole Derivative pendant for anion exchange membrane
Polymer, 2020Co-Authors: Xuefeng Li, Kaiqi Wang, Jinhui PangAbstract:Abstract As a key component of fuel cell, the anion exchange membrane (AEM) must present high durability, which includes dimensional stability，thermal stability，and alkali resistance. In order to obtain AEM with high performance, besides stable structure, the polymer should have high molecular weight and advantaged functional group position. In this work, a novel high molecular polymer precursor, poly(arylene ether ketone) (PAEK) with iodobenzene pendent was designed and prepared. And then, the function tetra-quaternary ammonium Carbazole was introduced onto polymer backbone by Ullmann grafting reaction and quaterisation . The obtained membranes exhibited good dimensional stability, appropriate thermal stability, and high ion conductivity. In addition, the membranes exhibited good alkaline resistance, as it still kept 90% of the conductivity after immersion in 4M NaOH solution for a week. Over all, the membrane in this work is promising for anion exchange membrane fuel cell.
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novel branched sulfonated poly arylene ether s based on Carbazole Derivative for proton exchange membrane
International Journal of Hydrogen Energy, 2020Co-Authors: Xiaocui Han, Jinhui Pang, Di Liu, Haibo Zhang, Zhenhua JiangAbstract:Abstract Proton exchange membrane (PEM) is a vital part of polymer electrolyte fuel cells (PEFCs). So it is of great importance to design the novel polymers for PEMs to improve the performance of PEFCs. Here two highly branched sulfonated copolymers (SBP-Cz-x) were synthesized based on a novel AB2 monomer. For all we know, it is the first time that the 9H site of Carbazole was used to prepare branched polymers. These copolymers given tough and transparent membranes by solvent casting method. SBP-Cz-x membranes exhibited excellent thermal stability and remarkable dimensional stability. Moreover, proton conductivity of SBP-Cz-x was very excellent. SBP-Cz-15 (IEC = 1.33 meq.g−1) owned high proton conductivity of 42.1 mS cm−1 at 80 °C. SBP-Cz-15 showed a pretty low swelling ratio of 12.7% with high water uptake (32.0%). SBP-Cz-x also owned remarkable oxidation stability. This study demonstrated that the strategy of fixing locally dense sulfonic acid groups on the branched points, which were surrounded by hydrophobic segment, could improve oxidative stability and dimensional stability efficiently.
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synthesis and properties of novel poly arylene ether s with densely sulfonated units based on Carbazole Derivative
Journal of Membrane Science, 2019Co-Authors: Xiaocui Han, Jinhui Pang, Di Liu, Yunji Xie, Zheng Chen, Haibo Zhang, Zhenhua JiangAbstract:Abstract The advancement of proton conductive applications will require the identification of new membrane with high-conductivity and good dimensional stability that can be readily obtained and cheap. We reported a novel rigid Carbazole Derivative and proton exchange membrane consisting of densely sulfonated Carbazole Derivative, which could form aggregated ionic cluster of sulfonic acid group and result in continuous broad-dimensional nanochannels. The SAXS analysis confirmed these copolymers owned large ion clusters. All of membranes prepared in this work were thermally stable at up to 250 o C. These membranes also exhibited excellent dimensional stability and outstanding proton conductivity. SPESK-Cz-15 with IEC = 2.07 meq g -1 showed the largest water uptake with a value of 107%, but the swelling ratio was only 36.4% at 100 o C, which was attributed to the artful structure of the copolymers. SPESK-Cz-15 showed very high proton conductivity (165.3 mS cm -1 at 80 o C), which was 1.53 times higher than that of Nafion 117 (108 mS cm -1 at 80 o C). Besides, the maximum power density of SPESK-Cz-15 was 1642.7 mV cm -2 at 80 o C under 95% RH. The stability of single cell based on SPESK-Cz-15 was remarkable. All above indicate that SPESK-Cz-x are potential materials for polymer electrolyte membrane fuel cells in the future.
Jiaxiang Yang - One of the best experts on this subject based on the ideXlab platform.
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a novel indolo 3 2 b Carbazole Derivative with d π a structure exhibiting aggregation enhanced emission and mechanofluorochromic properties
Dyes and Pigments, 2018Co-Authors: Yuyang Zhang, Yupeng Tian, Lin Kong, Jiaxiang YangAbstract:Abstract A novel symmetrical indolo[3,2-b]Carbazole Derivative (ICZ-CN) containing dicyanovinyl groups has been designed and synthesized. The typical D-π-A type conjugated compound exhibited an obvious intramolecular charge transfer (ICT) property, which was evidenced by UV-vis absorption, fluorescent emission spectroscopy and density functional theory (DFT) calculations. Meanwhile, ICZ-CN exhibited a strong aggregation-enhanced emission (AEE) characteristic. Interestingly, compound ICZ-CN showed a reversible mechanofluorochromic (MFC) property between yellow and orange-red emission by grinding-fuming processes. The MFC mechanism was investigated through the single crystal structure, the scanning electron microscope (SEM) and the powder X-ray diffraction (XRD). The results showed that the mechanofluorochromic property is attributed to the loose molecular packing by weak intermolecular hydrogen bond interactions was destroyed and generated the phase transformation from crystalline to amorphous states under external stimulations. The results would be of great help in understanding and designing new MFC materials.
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a novel Carbazole Derivative containing fluorobenzene unit aggregation induced fluorescence emission polymorphism mechanochromism and non reversible thermo stimulus fluorescence
CrystEngComm, 2018Co-Authors: Huichao Zhu, Yupeng Tian, Lin Kong, Shiyin Weng, Hong Zhang, Yu Lin Zhong, Jiaxiang YangAbstract:Herein, a novel Carbazole Derivative ((E)-2-(1-(9-butyl-9H-carbazol-3-yl)-3-(4-fluoro-phenyl)allylidene)malononitrile (3)) containing multi-cyano group and 4-fluoro-benzene unit was synthesized. This compound displayed aggregation-induced emission properties owing to the highly twisted conformation. It exhibited multi solid-state fluorescence emissions (yellow (3Y) and orange (3O)) and two crystalline polymorphs. Through single crystal structural analysis, we observed compound 3 with different conformations and variable molecular packing modes, which resulted in different solid-state fluorescence emissions, polymorphism, mechanochromic behaviors and unique non-reversible thermo-stimulus fluorescence. The fluorescence emission of the yellow solid displayed distinct red-shift after grinding, which is attributed to the breakup of the crystal structure, while that of the orange solid was not evident due to its stable and ordered molecular packing. Additionally, the yellow solid (3Y) also exhibited thermo-stimulus fluorescence, turning into 3O, and crystal phase transition. The lower energy and the compact packing modes of 3O should be collectively responsible for the unique behavior.
Sampak Samanta - One of the best experts on this subject based on the ideXlab platform.
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metal free one pot protocol for the preparation of unexpected Carbazole Derivative in water easy access to pyrimidoCarbazole and pyridocarbazolone Derivatives
ChemInform, 2015Co-Authors: Soumen Biswas, Debashis Majee, Anuradha Dagar, Sampak SamantaAbstract:Product (IIIa) is further transformed into pyrimidoCarbazole (IV), a topoisomerase II inhibitor, and the pyrimidocarbazolone (V), the skeleton of a variety of natural products such as strychnos alkaloids.
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Metal-Free One-Pot Protocol for the Preparation of Unexpected Carbazole Derivative in Water: Easy Access to PyrimidoCarbazole and Pyridocarbazolone Derivatives
Synlett, 2014Co-Authors: Soumen Biswas, Debashis Majee, Anuradha Dagar, Sampak SamantaAbstract:A novel, one-pot, metal-free-based catalytic system for the synthesis of a series of functionalized 1-methoxycarbonyl-2-aryl/alkyl-9H-Carbazole Derivatives has been successfully achieved in water medium by the combination of methyl 2-(3-formyl-1H-indol-2-yl)acetate with aryl/alkyl-substituted β-acroleins using DABCO (20 mol%), followed by treatment of HCl under air at heating conditions. This sequential one-pot protocol provides moderate to good yields (51–68%) of aforesaid compounds. In addition, biologically important Carbazole-fused new heterocyclic scaffolds can be synthesized through our procedure.
Yupeng Tian - One of the best experts on this subject based on the ideXlab platform.
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a novel indolo 3 2 b Carbazole Derivative with d π a structure exhibiting aggregation enhanced emission and mechanofluorochromic properties
Dyes and Pigments, 2018Co-Authors: Yuyang Zhang, Yupeng Tian, Lin Kong, Jiaxiang YangAbstract:Abstract A novel symmetrical indolo[3,2-b]Carbazole Derivative (ICZ-CN) containing dicyanovinyl groups has been designed and synthesized. The typical D-π-A type conjugated compound exhibited an obvious intramolecular charge transfer (ICT) property, which was evidenced by UV-vis absorption, fluorescent emission spectroscopy and density functional theory (DFT) calculations. Meanwhile, ICZ-CN exhibited a strong aggregation-enhanced emission (AEE) characteristic. Interestingly, compound ICZ-CN showed a reversible mechanofluorochromic (MFC) property between yellow and orange-red emission by grinding-fuming processes. The MFC mechanism was investigated through the single crystal structure, the scanning electron microscope (SEM) and the powder X-ray diffraction (XRD). The results showed that the mechanofluorochromic property is attributed to the loose molecular packing by weak intermolecular hydrogen bond interactions was destroyed and generated the phase transformation from crystalline to amorphous states under external stimulations. The results would be of great help in understanding and designing new MFC materials.
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a novel Carbazole Derivative containing fluorobenzene unit aggregation induced fluorescence emission polymorphism mechanochromism and non reversible thermo stimulus fluorescence
CrystEngComm, 2018Co-Authors: Huichao Zhu, Yupeng Tian, Lin Kong, Shiyin Weng, Hong Zhang, Yu Lin Zhong, Jiaxiang YangAbstract:Herein, a novel Carbazole Derivative ((E)-2-(1-(9-butyl-9H-carbazol-3-yl)-3-(4-fluoro-phenyl)allylidene)malononitrile (3)) containing multi-cyano group and 4-fluoro-benzene unit was synthesized. This compound displayed aggregation-induced emission properties owing to the highly twisted conformation. It exhibited multi solid-state fluorescence emissions (yellow (3Y) and orange (3O)) and two crystalline polymorphs. Through single crystal structural analysis, we observed compound 3 with different conformations and variable molecular packing modes, which resulted in different solid-state fluorescence emissions, polymorphism, mechanochromic behaviors and unique non-reversible thermo-stimulus fluorescence. The fluorescence emission of the yellow solid displayed distinct red-shift after grinding, which is attributed to the breakup of the crystal structure, while that of the orange solid was not evident due to its stable and ordered molecular packing. Additionally, the yellow solid (3Y) also exhibited thermo-stimulus fluorescence, turning into 3O, and crystal phase transition. The lower energy and the compact packing modes of 3O should be collectively responsible for the unique behavior.
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synthesis spectral and third order nonlinear optical properties of terpyridine zn ii complexes based on Carbazole Derivative with polyether group
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2015Co-Authors: Ming Kong, Yanqiu Liu, Hui Wang, Junshan Luo, Shengyi Zhang, Yupeng TianAbstract:Abstract Four novel Zn(II) terpyridine complexes (ZnLCl2, ZnLBr2, ZnLI2, ZnL(SCN)2) based on Carbazole Derivative group were designed, synthesized and fully characterized. Their photophysical properties including absorption and one-photon excited fluorescence, two-photon absorption (TPA) and optical power limiting (OPL) were further investigated systematically and interpreted on the basis of theoretical calculations (TD-DFT). The influences of different solvents on the absorption and One-Photon Excited Fluorescence (OPEF) spectral behavior, quantum yields and the lifetime of the chromophores have been investigated in detail. The third-order nonlinear optical (NLO) properties were investigated by open/closed aperture Z-scan measurements using femtosecond pulse laser in the range from 680 to 1080 nm. These results revealed that ZnLCl2 and ZnLBr2 exhibited strong two-photon absorption and ZnLCl2 showed superior optical power limiting property.
Heping Shi - One of the best experts on this subject based on the ideXlab platform.
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a novel Carbazole Derivative containing dimesitylboron units synthesis photophysical aggregation induced emission and electroluminescent properties
Dyes and Pigments, 2014Co-Authors: Heping Shi, Li Fang, Yanqin Miao, Wenxia Zhang, Xiuqing Dong, Hua WangAbstract:Abstract A novel Carbazole Derivative containing dimesitylboron groups, 3-dimesitylboryl-9-(4-(3-dimesitylborylcarbazolyl)phenyl)Carbazole has been successfully synthesized by introducing two dimesitylboron groups (two electron-acceptors) to 3-position and 3′-position of 1, 4-bis(carbazolyl)benzene (an electron-donor), respectively. The structure of the compound was fully characterized by elemental analysis, mass spectrometry and proton nuclear magnetic resonance spectroscopy methods. The electrochemical and photophysical properties of the compound were studied by electrochemical methods, UV–vis absorption spectroscopy and fluorescence spectroscopy. Our results show that the compound exhibits excellent thermal stability ( T d = 190 °C) and electrochemical stability as well as aggregation induced emission properties. The multi-layered organic light-emitting diodes device was fabricated by using the compound as non-doped emitter. The device shows good electroluminescent performances with the same blue emission color ( λ = 478 nm) at different voltages, a turn-on voltage of 3.8 V, a maximum luminance of 2784 cd/m 2 and a maximum luminance efficiency of 3.25 cd/A.
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a novel dimesitylboron substituted indolo 3 2 b Carbazole Derivative synthesis electrochemical photoluminescent and electroluminescent properties
Organic Electronics, 2013Co-Authors: Heping Shi, Jianxin Dai, Liwen Shi, Jiandong Yuan, Li Fang, Yanqin Miao, Hua Wang, Chuan DongAbstract:Abstract A novel indolo[3,2-b]Carbazole Derivative containing B(Mes) 2 groups, 5,11-dibutyl-2,8-bis(dimesitylboryl) indolo[3,2-b]Carbazole ( DBDMBICZ ), was synthesized and structurally characterized by elemental analysis, NMR, MS. The thermal, electrochemical and photophysical properties of DBDMBICZ were characterized by thermogravimetric analysis, electrochemical methods, UV–vis absorption spectroscopy and fluorescence spectroscopy. DBDMBICZ exhibited high fluorescence quantum yields ( Φ max = 0.76) in solution and excellent thermal stability ( T d = 290 °C, T g = 170 °C) and electrochemical stability. The multi-layered OLEDs devices with the configuration of ITO/NPB/CBP/light-emitting layer/Bphen/LiF/Al are fabricated by using DBDMBICZ as light-emitting layer. The devices show the same pure blue emissions at different voltages and relative good electroluminescent performances. The results indicate that DBDMBICZ has potential applications as an excellent optoelectronic material in optical field.