- Extension of N-Heteroacenes through a Four-Membered Ring
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The synthesis of novel π-extended N-heteroacenes, which have a large tetraazaacene subunit and a quinoxaline subunit connected through a four-membered ring, is reported. They were studied with experimental and computational methods in comparison to the corresponding tetraazaacenes. As found from the DFT calculation, the four-membered ring is a better linker than a five-membered ring or a C-C single bond to extend N-heteroacenes for a new design of n-type semiconductors in terms of the spatial delocalization and energy level of LUMO as well as the reorganization energy. In solution-processed thin film transistors, the π-extended N-heteroacenes are found to function as n-type semiconductors with field effect mobility of up to 0.02?cm2 V-1 s-1 under ambient conditions. Gang of four: This study demonstrates that N-heteroacenes can be extended through a four-membered ring into linear polycyclic frameworks with up to eight fused rings. It was found that the four-membered ring is a useful linker to extend electron delocalization for n-type organic semiconductors.
- Yang, Shuaijun,Shan, Bowen,Xu, Xiaomin,Miao, Qian
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- Synthesis and photovoltaic properties of 4,9-dithien-2′-yl-2,1,3-naphthothiadiazole-based D-A copolymers
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A series of donor-acceptor (D-A) conjugated copolymers (PBDTNT, PCDTNT, PFDTNT, and PNDTNT) based on a new acceptor unit of 4,9-dithien-2′-yl-2,1,3-naphthothiadiazole (DTNT) and different donor unit of benzodithiophene, carbazole, fluorene, or naphthalene, were synthesized and characterized as donor in polymer solar cells (PSCs). The effect of different donor units on the physicochemical properties of the polymers was investigated systematically. The copolymers showed relatively low-lying HOMO energy levels of around -5.45 eV, which is favorable for achieving high open-circuit voltage (Voc). The photovoltaic properties of these copolymers were studied by fabricating the PSCs with the polymer as donor and PC70BM as acceptor. PSCs based on PBDTNT:PC70BM (1:4, w/w) exhibited a power conversion efficiency (PCE) of 2.73%, a high Voc of 0.90 V, a short-circuit current density (Jsc) of 9.45 mA cm-2, and a fill factor of 32.1% via optimizing the device fabrication conditions, including the polymer/PC70BM blend ratio, solvent additive and treatment with methanol. With the same fabrication method, PSCs based on PCDTNT, PFDTNT, and PNDTNT showed PCEs of 2.26, 1.57 and 1.45%, and high Voc values of 0.90, 0.92 and 0.92 V, respectively.
- Shen, Ping,Bin, Haijun,Chen, Lixia,Zhang, Zhi-Guo,Li, Yongfang
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- A highly efficient near infrared organic solid fluorophore based on naphthothiadiazole derivatives with aggregation-induced emission enhancement for a non-doped electroluminescent device
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Two regioisomers of naphthothiadiazole derivatives with aggregation-induced emission enhancement exhibited a strong solid-state fluorescence emission in the range of 666-760 nm. A non-doped EL device emitted brilliant near infrared emission peaked at 754
- Chasing, Pongsakorn,Funchien, Patteera,Promarak, Vinich,Sudyoadsuk, Taweesak
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supporting information
p. 6305 - 6308
(2020/06/22)
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- Polymeric films based on blends of 6FDA-6FpDA polyimide plus several copolyfluorenes for CO2 separation
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Three emitting copolyfluorenes, based on 2,7-(9,9-dihexyl)fluorene and different aryl groups (1,4-bencene, PFH-B; 1,4-bencen-1,2,5-thiadiazole PFH-BT; 1,4-naphthalen-1,2,5-thiadiazole, PFH-NT), showing diverse acceptor character, in different proportions were blended with a polyimide 6FDA-6FpDA to make a series of films. These copolyfluorene-polyimide blends were prepared and characterized in the solid state, using several techniques. The fluorescence of conjugated polymers can be used as a tool to understand the formation of the membrane and also to increase permeability and selectivity in comparison to films which do not fluoresce. The relationship between the intrinsic fluorescence of conjugated polyfluorenes and their gas separation properties has been explored in order to establish the influence of the composition and the nature of the aryl group in the conjugated polymer, on the gas separation performance. In all cases, a low proportion of copolyfluorene (2/CH4 permselectivity properties than the original pure polyimide matrix. The best results were found for the samples that contain PFH-NT. These samples gave over 23% increase in the CO2 permeability with a 15% increase in CO2/CH4 selectivity. Finally, the loss of efficiency in conjugation mechanisms of absorption and emission of the samples could be explained on the basis of the π-stacking of the polymer chains, produced when a certain low percentage of conjugated polymers in the blend is surpassed. When this π-stacking starts, the gas permeation properties start to decline too.
- Tena,Vazquez-Guilló,Marcos-Fernández,Hernández,Mallavia
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p. 41497 - 41505
(2015/05/27)
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- A new type of light-emitting naphtho[2,3-c][1,2,5]thiadiazole derivatives: Synthesis, photophysical characterization and transporting properties
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We report a new series of naphtho[2,3-c][1,2,5]thiadiazole (NTD) derivatives which present both carrier transporting property and high fluorescence quantum yield. Optical absorption and emission property, film morphology and thermal stability of these com
- Wei, Peng,Duan, Lian,Zhang, Deqiang,Qiao, Juan,Wang, Liduo,Wang, Ruji,Dong, Guifang,Qiu, Yong
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experimental part
p. 806 - 818
(2009/04/21)
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