- Novel s-tetrazine-based dyes with enhanced two-photon absorption cross-section
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This paper reports the synthesis and the linear and non-linear absorption properties of a series of new tetrazine-based D-π-A-π-D and D-π-A type dyes. In these derivatives, a central tetrazine core was connected with one or two terminal triphenylamine moi
- Quinton, Cassandre,Chi, San-Hui,Dumas-Verdes, Ccile,Audebert, Pierre,Clavier, Gilles,Perry, Joseph W.,Alain-Rizzo, Valrie
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- Naphthodithiophene-2,1,3-benzothiadiazole copolymers for bulk heterojunction solar cells
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Two newly synthesized naphthodithiophene-based copolymers, PNB, exhibit a low optical bandgap of ~1.64 eV with which the solar cells fabricated from the blend of PNB and PC71BM afforded a power conversion efficiency of 5.3% with external quantum efficiency over 60% in a broad spectral range.
- Wang, Bao,Tsang, Sai-Wing,Zhang, Weifeng,Tao, Ye,Wong, Man Shing
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- Synthesis and characterization of triphenylamine flanked thiazole-based small molecules for high performance solution processed organic solar cells
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Two new small molecules, 5,5-bis(2-triphenylamino-3-decylthiophen-2-yl)-2, 2-bithiazole (M1) and 2,5-bis(2-triphenylamino-3-decylthiophen-2-yl)thiazolo[5, 4-d]thiazole (M2) based on an electron-donor triphenylamine unit and electron-acceptor thiophene-thiazolothiazole or thiophene-bithiazole units were synthesized by a palladium(0)-catalyzed Suzuki coupling reaction and examined as donor materials for application in organic solar cells. The small molecules had an absorption band in the range of 300-560 nm, with an optical band gap of 2.22 and 2.25 for M1 and M2, respectively. As determined by cyclic voltammetry, the highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels of M1 were -5.27 eV and -3.05 eV, respectively, which were 0.05 eV and 0.02 eV greater than that of M2. Photovoltaic properties of the small molecules were investigated by constructing bulk-heterojunction organic solar cell (OSC) devices using M1 and M2 as donors and fullerene derivatives, 6,6-phenyl-C61-butyric acid methyl ester (PC61BM) and 6,6-phenyl-C71-butyric acid methyl ester (PC71BM) as acceptors with the device architecture ITO/PEDOT:PSS/M1 or M2:PCBM/LiF/Al. The effect of the small molecule/fullerene weight ratio, active layer thickness, and processing solvent were carefully investigated to improve the performance of the OSCs. Under AM 1.5 G 100 mW/cm2 illumination, the optimized OSC device with M1 and PC71BM at a weight ratio of 1:3 delivered a power conversion efficiency (PCE) of 1.30%, with a short circuit current of 4.63 mA/cm 2, an open circuit voltage of 0.97 V, and a fill factor of 0.29. In contrast, M2 produced a better performance under identical device conditions. A PCE as high as 2.39% was recorded, with a short circuit current of 6.49 mA/cm2, an open circuit voltage of 0.94 V, and a fill factor of 0.39.
- Dutta, Pranabesh,Yang, Wooseung,Eom, Seung Hun,Lee, Soo-Hyoung
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- The Discovery of Citral-Like Thiophenes in Fried Chicken
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The isomers of 3,7-dimethyl-2,6-octadienal, more commonly known together as citral, are two of the most notable natural compounds in the flavor and fragrance industry. However, both isomers are inherently unstable, limiting their potential use in various applications. To identify molecules in nature that can impart the fresh lemon character of citral while demonstrating stability under acidic and thermal conditions has been a major challenge and goal for the flavor and fragrance industry. In the study of fried chicken, several alkyl thiophenecarbaldehydes were identified by gas chromatography-mass spectrometry and gas chromatography-olfactometry that provided a similar citral-like aroma. The potential mechanism of formation in fried chicken is discussed. Furthermore, in order to explore the organoleptic properties of this structural backbone, a total of 35 thiophenecarbaldehyde derivatives were synthesized or purchased for evaluation by odor and taste. Certain organoleptic trends were observed as the length of the alkyl or alkenyl chain increased or when the chain was moved to different positions on the thiophene backbone. The 3-substituted alkyl thiophenecarbaldehydes, specifically 3-butyl-2-thiophenecarbaldehyde and 3-(3-methylbut-2-en-1-yl)-2-thiophenecarbaldehyde, exhibited strong citrus and citral-like notes. Several alkyl thiophenecarbaldehydes were tested in high acid stability trials (4 °C vs 38 °C) and outperformed citral both in terms of maintaining freshness over time and minimizing off-notes. Additional measurements were completed to calculate the odor thresholds for a select group of thiophenecarbaldehydes, which were found to be between 4.7-215.0 ng/L in air.
- Cannon, Robert J.,Curto, Nicole L.,Esposito, Cynthia M.,Payne, Richard K.,Janczuk, Adam J.,Agyemang, David O.,Cai, Tingwei,Tang, Xiao-Qing,Chen, Michael Z.
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p. 5690 - 5699
(2017/07/24)
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- Cobalt-Catalyzed Reductive Alkylation of Heteroaryl Bromides: One-Pot Access to Alkylthiophenes, -furans, -selenophenes, and -pyrroles
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A practical and convenient Co-catalyzed alkylation method for the facile introduction of various alkyl chains into organic electronically significant heteroaryl compounds, including thiophenes, furans, selenophenes, and pyrroles, is reported. Under well-optimized reaction conditions, a wide range of alkylated heteroaryl compounds have beeen efficiently prepared in moderate to good isolated yields. Notably, 2- or 3-alkylthiophenes, which play a decisive role in polymer chemistry and organic materials, have been synthesized step-economically for the first time by this reductive-coupling methodology using inexpensive cobalt salts as catalysts. This straightforward synthetic procedure avoids the preparation of moisture-unstable organometallic reagents (RMgX or RZnX) required in conventional alkylation protocols. Various alkyl chains have been introduced into organic, electronically important heteroaryl compounds step-economically through Co-catalyzed reductive alkylation reactions. The resulting alkylheteroarenes are indispensable building blocks for polymer chemistry and π-functional organic materials.
- Cai, Deng-Jhou,Lin, Po-Han,Liu, Ching-Yuan
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p. 5448 - 5452
(2015/08/24)
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- Triphenylamine/tetrazine based π-conjugated systems as molecular donors for organic solar cells
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Conjugated systems built by connecting one electron-donor triphenylamine to an electron-withdrawing tetrazine have been prepared using various linkers. We describe here the synthesis, the electrochemical properties and some photophysical properties of the
- Quinton, Cassandre,Alain-Rizzo, Valérie,Dumas-Verdes, Cécile,Clavier, Gilles,Vignau, Laurence,Audebert, Pierre
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p. 9700 - 9713
(2015/12/01)
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- Synthesis and self-assembly of 5,5′-bis(phenylethynyl)-2,2′-bithiophene-based bolapolyphiles in triangular and square LC honeycombs
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A series of X-shaped 5,5′-bis(phenylethynyl)-2,2′-bithiophene-based bolaamphiphiles bearing two long lateral alkyl chains and two terminal glycerol groups has been synthesized by using Kumada and Sonogashira coupling reactions as key steps. The thermotropic liquid crystalline behavior of these compounds was investigated by POM, DSC and X-ray scattering. With elongation of the lateral alkyl chains two different kinds of liquid crystalline phases with honeycomb structures, ColhexΔ/p6mm, formed by (defective) triangular honeycomb cells, and Colsqu/p4mm with square cells were observed for these compounds. UV and PL measurements indicate fluorescent properties making them potential candidates for application in fluorescence sensor devices.
- Gao, Hongfei,Cheng, Huifang,Yang, Zonghan,Prehm, Marko,Cheng, Xiaohong,Tschierske, Carsten
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supporting information
p. 1301 - 1308
(2015/02/19)
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- Transition between triangular and square tiling patterns in liquid-crystalline honeycombs formed by tetrathiophene-based bolaamphiphiles
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A series of 5,5′′′-diphenyl tetrathiophenes with polar glycerol groups at each end and two lateral flexible chains self-assemble into a series of liquid-crystalline honeycombs, formed by the π-conjugated rods which enclose polygonal prismatic cells filled by the lateral chains. With increasing chain length a discontinuous transition from triangular to square honeycombs takes place. At this transition a periodic honeycomb composed of a mixture of square and triangular cells in a ratio 1:2 was formed at low temperature, whereas at higher temperature a hexagonal columnar phase composed of triangular and randomly distributed rhombic cells, a new kind of cybotactic nematic phase, and also a cybotactic isotropic phase, both composed of square honeycomb fragments, represent the intermediate states. This provides an example of a dynamic self-assembled system where, depending on the molecular mobility, the transition between two periodic structures with different symmetry either leads to an increase of complexity, or to a chaotic regime with reduced order.
- Cheng, Xiaohong,Gao, Hongfei,Tan, Xiaoping,Yang, Xueyan,Prehm, Marko,Ebert, Helgard,Tschierske, Carsten
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p. 3317 - 3331
(2013/07/26)
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- A bolaamphiphilic sexithiophene with liquid crystalline triangular honeycomb phase
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A new bolaamphiphile comprising a 5,5′′′′′- diphenyl-sexithiophene core with glycerol groups at each end and four lateral decyl chains was synthesized, which self-assembles into a liquid crystalline phase representing a nanoscale honeycomb composed of qua
- Bu, Wei,Gao, Hongfei,Tan, Xiaoping,Dong, Xing,Cheng, Xiaohong,Prehm, Marko,Tschierske, Carsten
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p. 1756 - 1758
(2013/03/14)
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- Dithiophene based X-shaped bolaamphiphiles: Liquid crystals with single wall honeycombs and geometric frustration
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A series of 5,5′-diphenyl-2,2′-dithiophene based X-shaped polyphiles with two long lateral alkyl chains and terminal glycerol groups was synthesized and the liquid crystalline phases formed by these compounds were investigated by polarizing microscopy, DSC and XRD. These compounds form square (p4mm and p4gm) and hexagonal (p6mm) columnar LC phases. In these mesophases the molecules organize into polygonal honeycombs where the π-conjugated cores form the walls, fused at the edges by the hydrogen bonding networks between the glycerol units and filled by the lateral alkyl chains. By elongation of these chains, a series of polygonal honeycomb phases with a "single wall" structure, ranging from triangular via square and pentagonal to hexagonal was observed. Most triangular honeycombs appear to be defective and can be considered as mixtures of triangular cylinders with orientationally randomized rhombic cylinders. The transition from this improper triangular honeycomb to the square honeycomb takes place via a disordered isotropic phase. Addition of water to this isotropic phase gives rise to a true triangular honeycomb LC phase. Replacing one of the long lateral chains by a small methyl group leads to honeycombs formed by double walls instead of single walls. UV investigations indicate π-stacking of the aromatic cores organized in the honeycomb walls, which is of interest for the potential application of these materials in self assembled arrays of organic electronic material. This journal is
- Gao, Hongfei,Ye, Yafei,Kong, Leiyang,Cheng, Xiaohong,Prehm, Marko,Ebert, Helgard,Tschierske, Carsten
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p. 10921 - 10931,11
(2020/09/15)
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- Using bis(pinacolato)diboron to improve the quality of regioregular conjugated co-polymers
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We demonstrate the use of bis(pinacolato)diboron to directly polymerize symmetric, bisbromo, thiophene-based monomers via a Suzuki homo-polymerization to form co-polymers in less steps than the corresponding co-polymerization. We compare this method to the commonly used Stille co-polymerization by preparing four thiophene-based co-polymers using both methods. We use MALDI-TOF mass spectrometry to show that this new method produces high-quality, uniform polymers with narrow distributions of end-groups. By varying the electronegativity of the monomers, we demonstrate rudimentary control over these end-groups, forming either bis-H-, mono-H-mono-Br-, or bis-Br-terminated polymers in order of increasing electronegativity.
- Brouwer, Frank,Alma, Jan,Valkenier, Hennie,Voortman, Thomas P.,Hillebrand, Jorrit,Chiechi, Ryan C.,Hummelen, Jan C.
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supporting information; scheme or table
p. 1582 - 1592
(2011/10/02)
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- Controlling blend film morphology by varying alkyl side chain in highly coplanar donor-acceptor copolymers for photovoltaic application
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A series of varied length alkyl substituted donor-acceptor (D-A) conjugated copolymers with benzo[1,2-b:4,5-b′]dithiophene (BDT) as donor and thiophene rings attached to both sides of the benzothiadiazole (TBT) moieties as acceptors were designed and synthesized. The optical and electrochemical properties showed that the absorption spectrum, the band gaps, and the energy levels of the copolymers were not affected by the varied substituted alkyls, and all these copolymers showed low band gaps around 1.75 eV. In addition, the morphologies of the blend film between copolymers and PCBM can be fine-tuned by increasing the length of substituted alkyl of the copolymers, changing from pea-like aggregation to interpenetrating network to grain-like aggregation. Bulk heterojunction photovoltaic devices were fabricated by using the copolymers as donors and (6,6)-phenyl C61-butyric acid methyl ester (PC 61BM) or (6,6)-phenyl C71-butyric acid methyl ester (PC71BM) as acceptors. The optimized photovoltaic performances showed the stable open-circuit voltage (Voc) in the range of 0.68 to 0.74 eV, and dramatically increasing short circuit current density (Jsc) by optimizing the blending morphologies of copolymer and PCBM films. The optimized photovoltaic performance with a Voc of 0.70 V, J sc of 7.19 mA/cm2, a fill factor (FF) of 0.52, and a power conversion efficiency (PCE) of 2.88%, was obtained by the copolymer PBDT-TBT-C8 (PBDT-TBT-C8:PC61BM, 1:3 w/w, in CB solution). This is due to its low band gap and interpenetrating network morphology of PBDT-TBT-C8:PC 61BM blend film. The photovoltaic device based on PBDT-TBT-C8:PC 71BM showed a Jsc of 8.6 mA/cm2 and a PCE of 3.15%.
- Li, Yaowen,Chen, Yujin,Liu, Xing,Wang, Zhong,Yang, Xiaoming,Tu, Yingfeng,Zhu, Xiulin
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scheme or table
p. 6370 - 6381
(2012/06/18)
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- Cross-couplings of alkyl halides with heteroaromatic halides, in water at room temperature
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Zn-mediated, Pd-catalyzed cross-coupling reactions between heteroaromatic and alkyl halides can be done at room temperature in pure water using a commercially available Pd catalyst and PTS, a nanomicelle-forming amphiphile. Notably, zinc metal inserts selectively into a carbon sp3-halide bond, while palladium adds oxidatively to a carbon sp2-bond.
- Krasovskiy, Arkady,Thomé, Isabelle,Graff, Julien,Krasovskaya, Valeria,Konopelski, Paul,Duplais, Christophe,Lipshutz, Bruce H.
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experimental part
p. 2203 - 2205
(2011/05/05)
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- Bithiophene-imide-based polymeric semiconductors for field-effect transistors: Synthesis, structure-property correlations, charge carrier polarity, and device stability
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Developing new high-mobility polymeric semiconductors with good processability and excellent device environmental stability is essential for organic electronics. We report the synthesis, characterization, manipulation of charge carrier polarity, and device air stability of a new series of bithiophene-imide (BTI)-based polymers for organic field-effect transistors (OFETs). By increasing the conjugation length of the donor comonomer unit from monothiophene (P1) to bithiophene (P2) to tetrathiophene (P3), the electron transport capacity decreases while the hole transport capacity increases. Compared to the BTI homopolymer P(BTimR) having an electron mobility of 10 -2 cm2 V-1 s-1, copolymer P1 is ambipolar with balanced hole and electron mobilities of ~10-4 cm2 V-1 s-1, while P2 and P3 exhibit hole mobilities of ~10-3 and ~10-2 cm2 V-1 s-1, respectively. The influence of P(BTimR) homopolymer Mn on film morphology and device performance was also investigated. The high Mn batch P(BTimR)-H affords more crystalline film microstructures; hence, 3- increased electron mobility (0.038 cm 2 V-1 s-1) over the low Mn one P(BTimR)-L (0.011 cm2 V-1 s-1). In a top-gate/bottom-contact OFET architecture, P(BTimR)-H achieves a high electron mobility of 0.14 cm2 V-1 s-1, only slightly lower than that of state-of-the-art n-type polymer semiconductors. However, the high-lying P(BTimR)-H LUMO results in minimal electron transport on exposure to ambient. Copolymer P3 exhibits a hole mobility approaching 0.1 cm2 V-1 s-1 in top-gate OFETs, comparable to or slightly lower than current state-of-the-art p-type polymer semiconductors (0.1-0.6 cm 2 V-1 s-1). Although BTI building block incorporation does not enable air-stable n-type OFET performance for P(BTimR) or P1, it significantly increases the OFET air stability for p-type P2 and P3. Bottom-gate/top-contact and top-gate/bottom-contact P2 and P3 OFETs exhibit excellent stability in the ambient. Thus, P2 and P3 OFET hole mobilities are almost unchanged after 200 days under ambient, which is attributed to their low-lying HOMOs (>0.2 eV lower than that of P3HT), induced by the strong BTI electron-withdrawing capacity. Complementary inverters were fabricated by inkjet patterning of P(BTimR)-H (n-type) and P3b (p-type).
- Guo, Xugang,Ortiz, Rocio Ponce,Zheng, Yan,Hu, Yan,Noh, Yong-Young,Baeg, Kang-Jun,Facchetti, Antonio,Marks, Tobin J.
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supporting information; experimental part
p. 1405 - 1418
(2011/04/16)
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- Liquid-crystalline triangle honeycomb formed by a dithiophene-based X-shaped bolaamphiphile
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Soft supramolecular triangles: The molecule shown displays a new liquid-crystalline phase formed by a periodic array of triangular cylinders. The cylinders are fused to form a honeycomb by hydrogen-bonding networks running along the vertices, and the cells are filled by molten alkyl chains. The thickness of the walls separating the compartments is equal to the width of the π-conjugated rods.
- Cheng, Xiaohong,Dong, Xing,Wei, Guanghui,Prehm, Marko,Tschierske, Carsten
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supporting information; scheme or table
p. 8014 - 8017
(2010/02/27)
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- Process for the kumada coupling reaction
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A method for the formation of 3-alkylthiophenes or 3-arylthiophenes from 3-halothiophenes. More particularly, improvements on the Kumada coupling reaction for the production of 3-alkylthiophenes or 3-arylthiophenes by reacting a 3-halothiophene with an alkylmagnesiumhalide or arylmagnesiumhalide Grignard reagent in the presence of a catalyst and a 2-methyl tetrahydrofuran solvent. The 2-methyl tetrahydrofuran solvent allows for higher concentrations of the Grignard reagent with minimal or no dithienyl side product generation, achieving higher product yields and at a lower cost than other known methods.
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Page/Page column 5
(2008/06/13)
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