The Experts below are selected from a list of 243 Experts worldwide ranked by ideXlab platform
Jingui Qin - One of the best experts on this subject based on the ideXlab platform.
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Design of organic dyes for dye-sensitized solar cells: Extending π-conjugation backbone via ‘Click’ reaction to improve photovoltaic performances
Dyes and Pigments, 2015Co-Authors: Tainan Duan, Cheng Zhong, Xingguo Chen, Ke Fan, Wei Cao, Tianyou Peng, Jingui QinAbstract:Abstract The organic dyes have been synthesized via a ‘Click’ reaction and employed in dye-sensitized solar cells, in which an electron-deficient 1,2,3-triazole unit is introduced to connect the Thienyl Group and the phenoxyl Group as π-linkers. Compared with the non-thiophene containing reference dye, these new dyes show stronger intramolecular charge transfer and higher molar extinction coefficient with incremental increase of Thienyl Groups. Thus, the short-circuit current of solar cells based on them is greatly increased. Moreover, the existence of 1,2,3-triazole unit is favorable for the charge separation that can retard the charge recombination and improve the open circuit voltage. Consequently, the solar cell based on the diThienyl containing dye presents the best performance with a Jsc of 10.00 mA cm−2, a Voc of 0.68 V and a FF of 0.71, corresponding to an overall conversion efficiency of 4.81% among them.
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New Kind of Hyperbranched Conjugated Polymers Containing Alkyl-Modified 2,4,6-Tris(thiophen-2-yl)-1,3,5-triazine Unit for Enhancing Two-Photon Absorption
Macromolecules, 2014Co-Authors: Pengcheng Zhou, Cheng Zhong, Xingguo Chen, Jingui Qin, Inês F. A. Mariz, Ermelinda M. S. MaçôasAbstract:Two series of hyperbranched polymers based on alkyl-modified 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine central units linked through fluorene bridges of different lengths have been synthesized via Suzuki coupling. The two series of polymers differ in the position of alkyl substitution within the Thienyl Group, which can be either closer to the triazine core (P0–P10) or to the fluorene bridge (P0′–P10′). Introduction of a hexyl Group at one of the β-positions of the Thienyl Group improves the solubility of the polymers. A good control over the ratio of triazine and fluorene units allows for the systematic study of the polymer composition effects on the electrochemical, linear, and nonlinear photophysical properties. The nonlinear absorption has been shown to have a noticeable promotion with increasing molar ratio of the triazine core, while the emission quantum yield decreases. The position of alkyl substitution within the Thienyl Group has a significant effect on the two-photon absorption cross section. Sub...
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thiophene fused benzothiadiazole a strong electron acceptor unit to build d a copolymer for highly efficient polymer solar cells
Chemistry of Materials, 2014Co-Authors: Pengcheng Zhou, Xingguo Chen, Zhiguo Zhang, Jingui QinAbstract:A novel strong electron-acceptor, thieno[2,3-f]-2,1,3-benzothiadiazole-6-carboxylate (BTT), was first designed and synthesized. By introducing two Thienyl Groups into BTT and then copolymerizing with Thienyl Group substituted benzo[1,2-b:4,5-b′]dithiophene (BDTT) unit, a low band gap D–A copolymer (PBTT-TBDTT) was obtained. Compared with its polymer analogue (PBT-TBDTT) with benzothiadiazole (BT) as an acceptor, PBTT-TBDTT exhibits stronger intramolecular charge transfer. Thus, it shows much broader absorption covering almost the whole visible light region (in the range of 300–850 nm) and narrower optical band gap around 1.45 eV with a large IP (ionization potential) at 5.35 eV. The maximum efficiency of PBTT-TBDTT based device reaches 6.07% which is much higher than that of PBT-TBDTT (3.24%), indicating that BTT unit is a promising electron-acceptor moiety to construct low band gap D–A copolymers for PSCs with high photovoltaic performances.
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Thiophene-Fused Benzothiadiazole: A Strong Electron-Acceptor Unit to Build D–A Copolymer for Highly Efficient Polymer Solar Cells
Chemistry of Materials, 2014Co-Authors: Pengcheng Zhou, Xingguo Chen, Zhiguo Zhang, Jingui QinAbstract:A novel strong electron-acceptor, thieno[2,3-f]-2,1,3-benzothiadiazole-6-carboxylate (BTT), was first designed and synthesized. By introducing two Thienyl Groups into BTT and then copolymerizing with Thienyl Group substituted benzo[1,2-b:4,5-b′]dithiophene (BDTT) unit, a low band gap D–A copolymer (PBTT-TBDTT) was obtained. Compared with its polymer analogue (PBT-TBDTT) with benzothiadiazole (BT) as an acceptor, PBTT-TBDTT exhibits stronger intramolecular charge transfer. Thus, it shows much broader absorption covering almost the whole visible light region (in the range of 300–850 nm) and narrower optical band gap around 1.45 eV with a large IP (ionization potential) at 5.35 eV. The maximum efficiency of PBTT-TBDTT based device reaches 6.07% which is much higher than that of PBT-TBDTT (3.24%), indicating that BTT unit is a promising electron-acceptor moiety to construct low band gap D–A copolymers for PSCs with high photovoltaic performances.
Xingguo Chen - One of the best experts on this subject based on the ideXlab platform.
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Design of organic dyes for dye-sensitized solar cells: Extending π-conjugation backbone via ‘Click’ reaction to improve photovoltaic performances
Dyes and Pigments, 2015Co-Authors: Tainan Duan, Cheng Zhong, Xingguo Chen, Ke Fan, Wei Cao, Tianyou Peng, Jingui QinAbstract:Abstract The organic dyes have been synthesized via a ‘Click’ reaction and employed in dye-sensitized solar cells, in which an electron-deficient 1,2,3-triazole unit is introduced to connect the Thienyl Group and the phenoxyl Group as π-linkers. Compared with the non-thiophene containing reference dye, these new dyes show stronger intramolecular charge transfer and higher molar extinction coefficient with incremental increase of Thienyl Groups. Thus, the short-circuit current of solar cells based on them is greatly increased. Moreover, the existence of 1,2,3-triazole unit is favorable for the charge separation that can retard the charge recombination and improve the open circuit voltage. Consequently, the solar cell based on the diThienyl containing dye presents the best performance with a Jsc of 10.00 mA cm−2, a Voc of 0.68 V and a FF of 0.71, corresponding to an overall conversion efficiency of 4.81% among them.
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New Kind of Hyperbranched Conjugated Polymers Containing Alkyl-Modified 2,4,6-Tris(thiophen-2-yl)-1,3,5-triazine Unit for Enhancing Two-Photon Absorption
Macromolecules, 2014Co-Authors: Pengcheng Zhou, Cheng Zhong, Xingguo Chen, Jingui Qin, Inês F. A. Mariz, Ermelinda M. S. MaçôasAbstract:Two series of hyperbranched polymers based on alkyl-modified 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine central units linked through fluorene bridges of different lengths have been synthesized via Suzuki coupling. The two series of polymers differ in the position of alkyl substitution within the Thienyl Group, which can be either closer to the triazine core (P0–P10) or to the fluorene bridge (P0′–P10′). Introduction of a hexyl Group at one of the β-positions of the Thienyl Group improves the solubility of the polymers. A good control over the ratio of triazine and fluorene units allows for the systematic study of the polymer composition effects on the electrochemical, linear, and nonlinear photophysical properties. The nonlinear absorption has been shown to have a noticeable promotion with increasing molar ratio of the triazine core, while the emission quantum yield decreases. The position of alkyl substitution within the Thienyl Group has a significant effect on the two-photon absorption cross section. Sub...
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thiophene fused benzothiadiazole a strong electron acceptor unit to build d a copolymer for highly efficient polymer solar cells
Chemistry of Materials, 2014Co-Authors: Pengcheng Zhou, Xingguo Chen, Zhiguo Zhang, Jingui QinAbstract:A novel strong electron-acceptor, thieno[2,3-f]-2,1,3-benzothiadiazole-6-carboxylate (BTT), was first designed and synthesized. By introducing two Thienyl Groups into BTT and then copolymerizing with Thienyl Group substituted benzo[1,2-b:4,5-b′]dithiophene (BDTT) unit, a low band gap D–A copolymer (PBTT-TBDTT) was obtained. Compared with its polymer analogue (PBT-TBDTT) with benzothiadiazole (BT) as an acceptor, PBTT-TBDTT exhibits stronger intramolecular charge transfer. Thus, it shows much broader absorption covering almost the whole visible light region (in the range of 300–850 nm) and narrower optical band gap around 1.45 eV with a large IP (ionization potential) at 5.35 eV. The maximum efficiency of PBTT-TBDTT based device reaches 6.07% which is much higher than that of PBT-TBDTT (3.24%), indicating that BTT unit is a promising electron-acceptor moiety to construct low band gap D–A copolymers for PSCs with high photovoltaic performances.
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Thiophene-Fused Benzothiadiazole: A Strong Electron-Acceptor Unit to Build D–A Copolymer for Highly Efficient Polymer Solar Cells
Chemistry of Materials, 2014Co-Authors: Pengcheng Zhou, Xingguo Chen, Zhiguo Zhang, Jingui QinAbstract:A novel strong electron-acceptor, thieno[2,3-f]-2,1,3-benzothiadiazole-6-carboxylate (BTT), was first designed and synthesized. By introducing two Thienyl Groups into BTT and then copolymerizing with Thienyl Group substituted benzo[1,2-b:4,5-b′]dithiophene (BDTT) unit, a low band gap D–A copolymer (PBTT-TBDTT) was obtained. Compared with its polymer analogue (PBT-TBDTT) with benzothiadiazole (BT) as an acceptor, PBTT-TBDTT exhibits stronger intramolecular charge transfer. Thus, it shows much broader absorption covering almost the whole visible light region (in the range of 300–850 nm) and narrower optical band gap around 1.45 eV with a large IP (ionization potential) at 5.35 eV. The maximum efficiency of PBTT-TBDTT based device reaches 6.07% which is much higher than that of PBT-TBDTT (3.24%), indicating that BTT unit is a promising electron-acceptor moiety to construct low band gap D–A copolymers for PSCs with high photovoltaic performances.
Pengcheng Zhou - One of the best experts on this subject based on the ideXlab platform.
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New Kind of Hyperbranched Conjugated Polymers Containing Alkyl-Modified 2,4,6-Tris(thiophen-2-yl)-1,3,5-triazine Unit for Enhancing Two-Photon Absorption
Macromolecules, 2014Co-Authors: Pengcheng Zhou, Cheng Zhong, Xingguo Chen, Jingui Qin, Inês F. A. Mariz, Ermelinda M. S. MaçôasAbstract:Two series of hyperbranched polymers based on alkyl-modified 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine central units linked through fluorene bridges of different lengths have been synthesized via Suzuki coupling. The two series of polymers differ in the position of alkyl substitution within the Thienyl Group, which can be either closer to the triazine core (P0–P10) or to the fluorene bridge (P0′–P10′). Introduction of a hexyl Group at one of the β-positions of the Thienyl Group improves the solubility of the polymers. A good control over the ratio of triazine and fluorene units allows for the systematic study of the polymer composition effects on the electrochemical, linear, and nonlinear photophysical properties. The nonlinear absorption has been shown to have a noticeable promotion with increasing molar ratio of the triazine core, while the emission quantum yield decreases. The position of alkyl substitution within the Thienyl Group has a significant effect on the two-photon absorption cross section. Sub...
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thiophene fused benzothiadiazole a strong electron acceptor unit to build d a copolymer for highly efficient polymer solar cells
Chemistry of Materials, 2014Co-Authors: Pengcheng Zhou, Xingguo Chen, Zhiguo Zhang, Jingui QinAbstract:A novel strong electron-acceptor, thieno[2,3-f]-2,1,3-benzothiadiazole-6-carboxylate (BTT), was first designed and synthesized. By introducing two Thienyl Groups into BTT and then copolymerizing with Thienyl Group substituted benzo[1,2-b:4,5-b′]dithiophene (BDTT) unit, a low band gap D–A copolymer (PBTT-TBDTT) was obtained. Compared with its polymer analogue (PBT-TBDTT) with benzothiadiazole (BT) as an acceptor, PBTT-TBDTT exhibits stronger intramolecular charge transfer. Thus, it shows much broader absorption covering almost the whole visible light region (in the range of 300–850 nm) and narrower optical band gap around 1.45 eV with a large IP (ionization potential) at 5.35 eV. The maximum efficiency of PBTT-TBDTT based device reaches 6.07% which is much higher than that of PBT-TBDTT (3.24%), indicating that BTT unit is a promising electron-acceptor moiety to construct low band gap D–A copolymers for PSCs with high photovoltaic performances.
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Thiophene-Fused Benzothiadiazole: A Strong Electron-Acceptor Unit to Build D–A Copolymer for Highly Efficient Polymer Solar Cells
Chemistry of Materials, 2014Co-Authors: Pengcheng Zhou, Xingguo Chen, Zhiguo Zhang, Jingui QinAbstract:A novel strong electron-acceptor, thieno[2,3-f]-2,1,3-benzothiadiazole-6-carboxylate (BTT), was first designed and synthesized. By introducing two Thienyl Groups into BTT and then copolymerizing with Thienyl Group substituted benzo[1,2-b:4,5-b′]dithiophene (BDTT) unit, a low band gap D–A copolymer (PBTT-TBDTT) was obtained. Compared with its polymer analogue (PBT-TBDTT) with benzothiadiazole (BT) as an acceptor, PBTT-TBDTT exhibits stronger intramolecular charge transfer. Thus, it shows much broader absorption covering almost the whole visible light region (in the range of 300–850 nm) and narrower optical band gap around 1.45 eV with a large IP (ionization potential) at 5.35 eV. The maximum efficiency of PBTT-TBDTT based device reaches 6.07% which is much higher than that of PBT-TBDTT (3.24%), indicating that BTT unit is a promising electron-acceptor moiety to construct low band gap D–A copolymers for PSCs with high photovoltaic performances.
Piet Herdewijn - One of the best experts on this subject based on the ideXlab platform.
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trans- and cis-S-C-C-S conformations in 5-(2,2'-dithien-5-yl)-2'-deoxyuridine
Acta Crystallographica Section C Crystal Structure Communications, 1997Co-Authors: Johan Wouters, Isabelle Creuven, Bernadette Norberg, Guy Evrard, F. Durant, A. Van Aerschot, Piet HerdewijnAbstract:The title compound, C 17 H 16 N 2 O 5 S 2 , adopts a transoidcisoid disordered crystal structure of the terminal Thienyl Group at room temperature, with occupancies of 0.55 and 0.45. The structure was solved by direct methods and refined by least-squares calculations to a final R of 0.048. Molecular cohesion is stabilized by hydrogen bonding involving the two hydroxyl Groups of the sugar moiety and the uridine ring.
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Synthesis and antiviral activity of 5-thien-2-yl-2'-deoxyuridine analogues
Journal of medicinal chemistry, 1993Co-Authors: Piet Wigerinck, L. Kerremans, P. Claes, Robert Snoeck, Maudgal P, De Clercq E, Piet HerdewijnAbstract:A number of 5-heteroaromatic-substituted 2'-deoxyuridines were synthesized from 5-iodo-2'-deoxyuridine using tetraorganotin reagents and palladium complexes as catalyst. The palladium-catalyzed cross-coupling reaction between 5-iodo-2'-deoxyuridine and stannylated heteroaromatics was optimized for the synthesis of the 5-thien-3-yl-2'-deoxyuridine and 5-furan-3-yl-2'-deoxyuridine. 5-(5-Iodothien-2-yl)-2'-deoxyuridine was used as starting material for the synthesis of 5-(5-methylthien-2-yl)-2'-deoxyuridine, 5-(5-vinylthien-2-yl)-2'-deoxyuridine, and 5-(5-ethynylthien-2-yl)-2'- deoxyuridine. 5-(5-Nitrothien-2-yl)-2'-deoxyuridine was synthesized using ceric ammonium nitrate as reagent. 5-(Isoxazol-5-yl)-2'-deoxyuridine was synthesized from 5-(3-oxopropyn-1-yl)-2'-deoxyuridine. Finally, 5-(5-chlorothien-2-yl)-beta-D-arabinofuranosyluracil and 5-(5-bromothien-2-yl)-beta-D-arabinofuranosyluracil were obtained by halogenation of 5-thien-2-yl-beta-D-arabinofuranosyluracil. Introduction of an alkyl substituent in the 5-position of the Thienyl Group of 5-thien-2-yl-2'-deoxyuridine or substitution of the 2-deoxyribofuranose ring by an arabinofuranose moiety gave decreased activity against HSV-1 and VZV replication when compared with the 5"-halogenated-5-thien-2-yl-2'-deoxyuridines. 5-(5-Bromothien-2-yl)-2'-deoxyuridine caused prompt healing of HSV-1 keratitis when administered as eye drops (0.2%) to rabbits.
Masahiro Irie - One of the best experts on this subject based on the ideXlab platform.
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pka switching induced by the change in the π conjugated system based on photochromism
Chemistry: A European Journal, 2006Co-Authors: Yuka Odo, Kenji Matsuda, Masahiro IrieAbstract:Two diarylethene derivatives 1 a and 2 a containing a 2,5-diaryl-3-Thienyl Group have been designed and synthesized. The pK(a) values of these compounds change upon photoirradiation. They have a phenol Group as a proton source and a pyridinium Group as an acceptor unit at each end of the pi-conjugated chain. The cyclization/cycloreversion reactions can be used to control the length of the pi-conjugated chain between the proton source and the acceptor. The change in the pi-conjugated chain length caused the pK(a)-switching.
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pKa Switching Induced by the Change in the π‐Conjugated System Based on Photochromism
Chemistry (Weinheim an der Bergstrasse Germany), 2006Co-Authors: Yuka Odo, Kenji Matsuda, Masahiro IrieAbstract:Two diarylethene derivatives 1 a and 2 a containing a 2,5-diaryl-3-Thienyl Group have been designed and synthesized. The pK(a) values of these compounds change upon photoirradiation. They have a phenol Group as a proton source and a pyridinium Group as an acceptor unit at each end of the pi-conjugated chain. The cyclization/cycloreversion reactions can be used to control the length of the pi-conjugated chain between the proton source and the acceptor. The change in the pi-conjugated chain length caused the pK(a)-switching.
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new photoswitching unit for magnetic interaction diarylethene with 2 5 bis arylethynyl 3 Thienyl Group
Journal of the American Chemical Society, 2005Co-Authors: Naoki Tanifuji, Masahiro Irie, Kenji MatsudaAbstract:Photoswitching of the intramolecular magnetic interaction was demonstrated using diarylethenes with 2,5-bis(arylethynyl)-4-methyl-3-Thienyl side Group. Two nitroxide radicals were placed at each end of the 2,5-bis(arylethynyl)-4-methyl-3-Thienyl Group. Three kinds of aryl Groups, 2,5-Thienylene, p-phenylene, and m-phenylene Groups, were used in the arylethynyl moiety. The diarylethene photoswitching units have an extended π-conjugated chain on one side of the diarylethene. The photochromic reactivity was dependent on the arylethynyl Group. Diarylethenes with m-phenylene Group showed an efficient photochromic reactivity. Along with the photochromic reaction the diarylethenes showed photoswitching of an ESR spectrum originating from the change in the magnetic interaction between two unpaired electrons. The open-ring isomer showed stronger exchange interaction than the photogenerated closed-ring isomer. The magnetic interaction between two radicals via the π-conjugated chain was altered by photocyclization d...
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thermally irreversible photochromic systems reversible photocyclization of 2 1 benzothiophen 3 yl 3 2 or 3 Thienyl maleimide derivatives
Bulletin of the Chemical Society of Japan, 1998Co-Authors: Kingo Uchida, Yuichi Kido, Tadatsugu Yamaguchi, Masahiro IrieAbstract:Non-symmetric diarylethenes that have a 1-benzothiophene ring on one end and a 2-Thienyl or 3-Thienyl Group on the other end of the double bond of maleimide were synthesized in order to study the effects of the substitution position of the thiophene ring on the absorption bands and the reactivities. The open-and closed-ring forms of N-cyanomethyl-2-(2,4-dimethyl-5-phenyl-3-Thienyl)-3-(2-methoxy-1-benzothiophen-3-yl)maleimide showed absorption bands at 420 and 563 nm in hexane, respectively. When 3-Thienyl was changed to 2-Thienyl, the absorption bands of N-cyanomethyl-2-(3,4-dimethyl-5-phenyl-2-Thienyl)-3-(2-methoxy-1-benzothiophen-3-yl)maleimide shifted to 448 nm (the open-ring form) and 487 nm (the closed-ring form), respectively. The cyclization and ring-opening quantum yields were also dependent on the substitution position. The cyclization yield decreased from 0.30 to 0.03 by changing the position from 3- to 2-Thienyl, while the ring-opening yield increased from 0.03 to 0.13. No absorption spectral c...