- Tetrathiahexacene as building block for solution-processable semiconducting polymers: Exploring the monomer size limit
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A larger fused monomer in a polythiophene chain which can improve stability and device performance has been reported. The largest building block in a soluble polythiophene so far is tetrathienoacene (P3). This polymer is very stable toward oxidation in an organic field-effect transistor and also shows high charge-carrier mobilities. The polymerization using dibromodithiophene as comonomer was performed using Pd(PPh3)4 as catalyst in toluene. The reaction mixture was heated for 40 minutes in the microwave to 150 °C with a power density of 70 W/mL. In a field-effect transistor, a good device characteristic, which is low contact resistance and low hysteresis, have been measured. The field-effect mobility does not yet reach values needed for applications but is likely to be achieved after more processing optimizations.
- Rieger, Ralph,Beckmann, Dirk,Pisula, Wojciech,Kastler, Marcel,Muellen, Klaus
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Read Online
- Synthesis and properties of thiophene-fused benzocarborane
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The o-carborane-based π-conjugated compound, benzocarborano- [2,1-b:3,4-b']dithiophene was synthesized. Its crystal structure revealed high coplanarity for the two thiophene rings of the 2,2'-bithiophene skeleton, which is fixed in the cisoid structure by the o-carborane unit. Theoretical calculations indicated non-aromaticity for its center C6 ring moiety as well as decreased HOMO and LUMO levels. The o-carborane moiety provides an electron-withdrawing character to the 2,2'-bithiophene unit through an inductive effect. Fused carboranes: The o-carborane-based π-conjugated compound, benzocarborano[2,1-b:3,4-b']dithiophene, was synthesized (see scheme). The 2,2'-bithiophene unit is fixed in the cisoid structure with high planarity by the o-carborane unit. The o-carborane moiety provides an electron-withdrawing character to the 2,2'-bithiophene unit through an inductive effect. Copyright
- Morisaki, Yasuhiro,Tominaga, Masato,Chujo, Yoshiki
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p. 11251 - 11257,7
(2012)
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Read Online
- Tuning the antiaromatic character and charge transport of pentalene-based antiaromatic compounds by substitution
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Understanding the structure-property relationships in antiaromatic molecules is crucial for controlling their electronic properties and designing new organic optoelectronic materials. Here we report the design, synthesis, and characterization of three new antiaromatic molecules (Pn, n = 1-4) based on the pentalene (P) antiaromatic core, to investigate how electron-donating and electron-accepting substituents affect P1-P4 properties. As expected, the optical, HOMO and LUMO energy levels and electronic structure are greatly modulated by core substitution. Compared to the unsubstituted compound (P1), P3 and P4 containing strong electron-withdrawing units reduced antiaromaticity as assessed by nucleus-independent chemical shift (NICS) calculations compared with P2, which is functionalized with strong electron-donating units, showing that substitution strongly tunes local antiaromaticity. Organic field-effect transistors (OFETs) fabricated using these materials indicate that P2 has an average hole mobility of ~10-4 cm2 V-1 s-1 while P3 has an average electron mobility of up to 0.03 cm2 V-1 s-1, versus FET-inactive P1. Therefore, introduction of strong π-extended electron-withdrawing or electron-donating substituents onto an antiaromatic core is an effective strategy to switch-on charge transport capacity. This journal is
- Chen, Yao,Facchetti, Antonio,Huang, Yan,Li, Guoping,Liu, Jueshan,Lu, Zhiyun,Marks, Tobin J.,Pang, Zhenguo,Wu, Jianglin
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supporting information
p. 2724 - 2731
(2022/03/01)
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- Domino Direct Arylation and Cross-Aldol for Rapid Construction of Extended Polycyclic π-Scaffolds
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Five-membered aromatic heterocycles are a ubiquitous skeleton of π-conjugated organic compounds, and their incorporation requires synthetic protocols that are not easily industrially sustainable or scalable. Improved methodologies for their insertion into π-scaffolds are therefore necessary. We report an efficient and scalable protocol involving a one-pot cross-Aldol direct arylation reaction protocol for the rapid construction of thiophene- and furan-based π-extended organic materials.
- Nitti, Andrea,Bianchi, Gabriele,Po, Riccardo,Swager, Timothy M.,Pasini, Dario
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supporting information
p. 8788 - 8791
(2017/07/12)
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- ORGANIC SEMICONDUCTING COMPOUNDS AND RELATED OPTOELECTRONIC DEVICES
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The present teachings relate to new organic semiconducting compounds and their use as active materials in organic and hybrid optical, optoelectronic, and/or electronic devices such as photovoltaic cells, light emitting diodes, light emitting transistors, and field effect transistors. The present compounds can provide improved device performance, for example, as measured by power conversion efficiency, fill factor, open circuit voltage, field-effect mobility, on/off current ratios, and/or air stability when used in photovoltaic cells or transistors. The present compounds can have good solubility in common solvents enabling device fabrication via solution processes.
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Paragraph 0184-0185
(2017/05/02)
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- Synthesis and properties of thiophene-fused benzocarborane
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The o-carborane-based π-conjugated compound, benzocarborano- [2,1-b:3,4-b']dithiophene was synthesized. Its crystal structure revealed high coplanarity for the two thiophene rings of the 2,2'-bithiophene skeleton, which is fixed in the cisoid structure by the o-carborane unit. Theoretical calculations indicated non-aromaticity for its center C6 ring moiety as well as decreased HOMO and LUMO levels. The o-carborane moiety provides an electron-withdrawing character to the 2,2'-bithiophene unit through an inductive effect. Fused carboranes: The o-carborane-based π-conjugated compound, benzocarborano[2,1-b:3,4-b']dithiophene, was synthesized (see scheme). The 2,2'-bithiophene unit is fixed in the cisoid structure with high planarity by the o-carborane unit. The o-carborane moiety provides an electron-withdrawing character to the 2,2'-bithiophene unit through an inductive effect. Copyright
- Morisaki, Yasuhiro,Tominaga, Masato,Chujo, Yoshiki
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p. 11251 - 11257
(2013/01/14)
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- Enhancing sensing of nitroaromatic vapours by thiophene-based polymer films
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Optical sensing, via fluorescence quenching, of nitroaromatic vapours using polythiophenes has received limited attention due to their rather low sensory response. We hypothesized that a dipolar 1,2,3-triazole moiety can enhance the interaction of DNT and TNT with the polymer in thin films and bulky side chains can decrease the chain packing in thin films resulting in enhanced analyte diffusion. Herein we show that thin films of thiophene-based polymers containing 1,2,3-triazole with appropriate alkyl side chains show enhanced fluorescence quenching in the presence of nitroaromatic vapours.
- Nagarjuna,Kumar, Abhishek,Kokil, Akshay,Jadhav, Kedar G.,Yurt, Serkan,Kumar, Jayant,Venkataraman
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scheme or table
p. 16597 - 16602
(2012/06/18)
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- Impact of pendant 1,2,3-triazole on the synthesis and properties of thiophene-based polymers
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π-Conjugated moieties are often attached to conjugated polymers to systematically alter their electronic properties. Herein, we report the synthesis and properties of a thiophene polymer bearing a triazole moiety in the third position. Through NMR-based quenching studies, we show that the placement of the triazole moiety alters reaction pathway of the Ni(0)-mediated Grignard metathesis polymerization possibly through chelation. When compared with a triazole on the main chain, the pendant triazole moiety acts as an electron donor and lowers the band gap of the polymer. The triazole moiety also does not hinder the packing of the conjugated backbone. We also show that the fluorescence of this polymer is quenched with PCBM, indicating its potential as a candidate for organic photovoltaic devices.
- Nagarjuna,Yurt, Serkan,Jadhav, Kedar G.,Venkataraman
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experimental part
p. 8045 - 8050
(2011/11/29)
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- Selective metallation of 3-halothiophenes: Practical methods for the synthesis of 2-bromo-3-formylthiophene
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Selective lithiation of 3-bromothiophene was accomplished under controlled conditions without formation of undesired thienyllithium compounds. A thienyl Grignard reagent derived from 2-bromo-3-iodothiophene was transformed into 2-bromo-3-formylthiophene in high selectivity by formylation with dimethylformamide (DMF) at optimal reaction temperature. Copyright Taylor & Francis Group, LLC.
- Sonoda, Motohiro,Kinoshita, Shoko,Luu, Thanh,Fukuda, Hiroshi,Miki, Koji,Umeda, Rui,Tobe, Yoshito
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experimental part
p. 3315 - 3323
(2011/03/20)
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