- Benzo[1,2-b:4,5-b']dithiophene-based copolymers applied in bottom-contact field-effect transistors
-
Three copolymers of benzo[1,2-b:4,5-b']dithiophene and 3,3'-bis(alkyl)-5,5'-bithiophene (dodecyl, tetradecyl and hexadecyl side chains) have been synthesized through Stille copolymerization. The polymers have number-average molecular weights over 20 kg/mol, are well-packed in the bulk and thin film, and possess an ionization potential of -5.1 eV in thin film, which offers stability versus oxidation in environmental conditions. The thin film packing of the polymer with dodecyl side chains leads to an excimeric emission upon excitation, which is not observed for longer side chain lengths. The presence of the dimers responsible for this excimer formation results in a device performance improvement as well. Field-effect transistors fabricated from these copolymers have On/Off ratios >107, equal saturation and linear hole mobilities above 10-2 cm2/Vs, almost no hysteresis and turn-on voltages around 0 V in bottom-contact devices.
- Leenen, Mark A.M.,Cucinotta, Fabio,Pisula, Wojciech,Steiger, Jürgen,Anselmann, Ralf,Thiem, Heiko,De Cola, Luisa
-
-
Read Online
- Energy Level Engineering of Donor Polymers via Inductive and Resonance Effects for Polymer Solar Cells: Effects of Cyano and Alkoxy Substituents
-
Fine tuning the energy levels of donor polymers is a critically important step toward achieving high power conversion efficiencies in polymer solar cells (PSCs). We systematically controlled the energy levels of donor polymers by introducing cyano (CN) and alkoxy (OR) groups into the 4,4′-didodecyl-2,2′-bithiophene (BT) unit in a step-by-step fashion, thereby varying the inductive and resonance effects. The three monomer units (BT, BTC, and BTCox) were polymerized with benzo[1,2-b:4,5-b′]dithiophene (BDT) as a counter unit to afford three polymers (PBDT-BT, PBDT-BTC, and PBDT-BTCox). The highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels decreased significantly upon the introduction of CN groups, and these levels increased slightly upon attachment of the OR groups, in good agreement with the measured open-circuit voltages of the three polymer devices. The strong inductive and resonance effects present in PBDT-BTCox narrowed the polymer band gap to 1.74 eV to afford a power conversion efficiency of 5.06%, the highest value achieved among the three polymers.
- Kim, Heung Gyu,Kim, Min,Clement, J. Arul,Lee, Jaewon,Shin, Jisoo,Hwang, Hyeongjin,Sin, Dong Hun,Cho, Kilwon
-
-
Read Online
- Air-stable, solution-processable n-channel and ambipolar semiconductors for thin-film transistors based on the indenofluorenebis(dicyanovinylene) core
-
We present here the synthesis, characterization, and field-effect performance of a novel n-channel semiconducting molecule TIFDMT and of the corresponding thiophene-based copolymer P-IFDMT4 based on the indenofluorenebis(dicyanovinylene) core. TIFDMT-based field-effect transistors fabricated by spin-coating exhibit high electron mobilities of 0.10-0.16 cm2/V s in air, low turn-on voltages (~0 to +5 V), and high on/off ratios of 107-108. These devices also exhibit excellent air stability over a prolonged time of storage in ambient conditions. P-IFDMT4-based devices exhibit the first example of an air-stable ambipolar polymer processable from solution. Copyright
- Usta, Hakan,Facchetti, Antonio,Marks, Tobin J.
-
-
Read Online
- Thiophene-benzothiadiazole-thiophene (D-A-D) based polymers: Effect of donor/acceptor moieties adjacent to D-A-D segment on photophysical and photovoltaic properties
-
New push-pull copolymers based on thiophene (donor) and benzothiadiazole (acceptor) units, poly[4,7-bis(3-dodecylthiophene-2-yl) benzothiadiazole-co- thiophene] (PT3B1) and poly[4,7-bis(3-dodecylthiophene-2-yl) benzothiadiazole-co-benzothiadiazole] (PT2B2), are designed and synthesized via Stille and Suzuki coupling routes respectively. Gel permeation chromatography shows the number average molecular weights are 31100 and 8400 g mol-1 for the two polymers, respectively. Both polymers have shown absorption throughout a wide range of the UV-vis region, from 300 to 650 nm. A significant red shift of the absorption edge is observed in thin films compared to solution of the copolymers; the optical band gap is in the range of 1.7 to 1.8 eV. Cyclic voltammetry indicates reversible oxidation and reduction processes with HOMO energy levels calculated to be in the range of 5.2 to 5.4 eV. Upon testing both materials for organic field-effect transistors (OFETs), PT3B1 showed a hole mobility of 6.1 × 10-4 cm2 V-1 s -1, while PT2B2 did not show any field effect transport. Both copolymers displayed a photovoltaic response when combined with a methanofullerene as an electron acceptor. The best performance was achieved when the copolymer PT3B1 was blended with [70]PCBM in a 1:4 ratio, exhibiting a short-circuit current of 7.27 mA cm-2, an open circuit voltage of 0.85 V, and a fill factor of 41% yielding a power conversion efficiency of 2.54% under simulated air mass (AM) 1.5 global (1.5 G) illumination conditions (100 mW cm-2). Similar devices utilizing PT2B2 in place of PT3B1 demonstrated reduced performance with a short-circuit current of 4.8 mA cm -2, an open circuit voltage of 0.73 V, and a fill factor of 30% resulting in a power conversion efficiency of roughly 1.06%.
- Sonar, Prashant,Williams, Evan L.,Singh, Samarendra P.,Dodabalapur, Ananth
-
-
Read Online
- Thiophene-benzothiadiazole based donor–acceptor–donor (D-A-D) bolaamphiphiles, self-assembly and photophysical properties
-
Bolaamphiphilies with D-A-D type π-conjugated rigid cores composed by thiophenes as donors (D) and benzothiadiazole (BTD) as central acceptor (A) have been synthesised. Their self-assemblies and photophysical properties were investigated by polarising optical microscope, differential scanning calorimetry, X-ray diffraction and scanning electron microscopy. Such compounds can self-assemble into honeycomb cylinder mesophases with Colhex?/p6mm and Colsqu/p4mm lattices in their pure states as well as organogels with different morphologies in organic solvents. Their absorption spectra cover nearly the entire visible light range and their band gaps are relatively low. Tetrathiophene BTD based bolaamphilphiles (BT4/n) with higher D/A ratios than the bisthiophene BTD bolaamphilphiles (BT2/n) can self-assemble into more ordered nanostructures in both bulk states and solution. Both the absorption and emission peaks of BT4/n are strongly red shifted. The influence of the molecular conformation, the conjugated core length, as well as the D/A ratio on the self-assemble and photophysical characteristics of such D-A-D bolaamphiphiles are discussed.
- Chang, Qing,Cheng, Xiaohong,Ding, Wei,Ma, Tao,Zhang, Lin
-
-
- Structural Insight into Aggregation and Orientation of TPD-Based Conjugated Polymers for Efficient Charge-Transporting Properties
-
In this study, we obtained a new structural insight into the charge-transporting properties in TPD-based polymers that cannot be solely explained in terms of the type of orientation. We synthesized two types of copolymers comprising mono-TPD or bis-TPD as the accepting unit. Although the planarity and energy levels are similar with the mono-TPD unit, the aggregation state is quite different, and the X-aggregation tendency seems to be stronger when the bis-TPD unit is incorporated. In the case of TPD1, an effective π-πorbital overlap is found to originate from the H-aggregates, and 3D charge transport pathways are formed with a bimodal orientation of edge-on and face-on, resulting in an efficient charge transportation (1.84 cm2·V-1·s-1 of hole and 0.31 cm2·V-1·s-1 of electron). In contrast, despite the well-aligned edge-on orientation of TPD2, it exhibited a relatively very low mobility and splitted emission characteristics in photoluminescence spectra because of the tilted intermolecular stacking pattern with an X-shape (0.015 cm2·V-1·s-1 for hole and 0.16 cm2·V-1·s-1 for electron). An overall characterization of the semiconducting polymers was performed, and it was found that the type of aggregation in the final thin films, such as H- or X-aggregation, is indeed important and perhaps more important than the orientation to obtain polymers with a high charge carrier mobility.
- Lim, Dae-Hee,Kim, Yeon-Ju,Kim, Yeong-A,Hwang, Kyoungtae,Park, Jong-Jin,Kim, Dong-Yu
-
p. 4629 - 4638
(2019/05/08)
-
- Intermolecular Arrangement of Fullerene Acceptors Proximal to Semiconducting Polymers in Mixed Bulk Heterojunctions
-
Precise control of the molecular arrangements at the interface between the electron donor and acceptor in mixed bulk heterojunctions (BHJs) remains challenging, despite the correlation between structural characteristics and efficiency in organic photovoltaics (OPVs). This study reveals that the substitution patterns of linear and branched alkyl side chains on electron-donating/-accepting alternating copolymers can control the positions of an acceptor molecule (C60) around the π-conjugated main chains in mixed BHJs. Two-dimensional solid-state NMR demonstrates a marked difference in the location of C60 in the blend films. A copolymer with an electron-accepting unit positioned in close proximity to C60 demonstrated higher OPV performance in combination with various fullerene derivatives. This molecular design offers precise control over the interfacial molecular structure, thereby paving the way for overcoming the current limitations of OPVs comprising mixed BHJs.
- Wang, Chao,Nakano, Kyohei,Lee, Hsiao Fang,Chen, Yujiao,Hong, You-Lee,Nishiyama, Yusuke,Tajima, Keisuke
-
supporting information
p. 7034 - 7039
(2018/06/15)
-
- Chemical synthesis and application research of cyanogroup containing functional material for modifying perovskite layer in perovskite solar cell
-
The invention aims at designing and synthesizing a cyanogroup compound and modifying a perovskite layer in a perovskite solar cell structure. According to an implementation method, a layer of modification material is arranged on the surface of perovskite in a spin coating manner, cyanogroups in material molecules and I in the perovskite structure interact, surface charges of the modification material are dispersed, meanwhile, I migration is reduced, and therefore the stability of the perovskite layer is improved; and benzene ring and alkyl chain components in the molecular structure can achieve the functions of improving interfacial compatibility and reducing the surface defects, and finally the aim of improving the performance of a perovskite solar cell is achieved. Ar in a chemical formula (1) (please see the specification) is a following aromatic compound (please see the specification). Ar in a chemical formula (2) (please see the specification) is a following aromatic compound (please see the specification). R1 is -CN or a chemical formula (please see the specification), and R2 is 1-16 alkyl chains.
- -
-
Paragraph 0022; 0025; 0026
(2017/05/23)
-
- Synthesis of donor-acceptor copolymer using benzoselenadiazole as acceptor for OTFT
-
Donor-acceptor-based poly(E)-4-(3,4′-didodecyl-5′-(2-(3-dodecylthiophen-2-yl)vinyl)-2,2′-bithiophen-5-yl)-7-(4-dodecylthiophen-2-yl)benzo[c][1,2,5]selenadiazole (11) has been synthesized by a Stille coupling reaction. This polymer has a low energy band gap between the HOMO and LUMO energy levels of 1.75 eV. The polymer exhibited good thermal stability. An OTFT prepared using this polymer displayed high hole mobility of 0.097 cm2 V-1 s-1 at 200°C, a high on/off ratio of 7.8 × 104, and a low threshold voltage of 11.2 V. When compared with as-cast films, annealed films exhibited higher mobility, which was attributed to an increase in crystallinity with an increase in the annealing temperature.
- Shaik, Baji,Han, Jin-Hee,Song, Dong Jin,Kang, Hun-Min,Kim, Ye Beyeol,Park, Chan Eon,Lee, Sang-Gyeong
-
p. 4070 - 4076
(2016/01/20)
-
- Synthesis and evaluation of thiophene-based organic dyes containing a rigid and nonplanar donor with secondary electron donors for use in dye-sensitized solar cells
-
We demonstrate herein the divergent synthesis of six dyes containing our originally developed rigid and nonplanar donor with three different secondary electron donors (SEDs), namely thiophene, 4-methoxybenzene, and diphenylethene. Evaluation of the photop
- Fuse, Shinichiro,Takahashi, Ryota,Maitani, Masato M.,Wada, Yuji,Kaiho, Tatsuo,Tanaka, Hiroshi,Takahashi, Takashi
-
supporting information
p. 508 - 517
(2016/02/18)
-
- Transition between triangular and square tiling patterns in liquid-crystalline honeycombs formed by tetrathiophene-based bolaamphiphiles
-
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
-
p. 3317 - 3331
(2013/07/26)
-
- Synthesis and characterization of a novel ambipolar polymer semiconductor based on a fumaronitrile core as an electron-withdrawing group
-
Two conjugated polymers containing stilbene and fumaronitrile moieties were synthesized to investigate their electronic properties by the existence of electron-withdrawing cyano groups on a vinylene backbone. The cyclic voltammetry investigation and time-dependent density functional theory calculations indicated that the cyano substituents lowered the lowest unoccupied molecular orbital (LUMO) energy level by about 0.65 and 0.63 eV, respectively. The lowering of the LUMO energy levels due to the electron-withdrawing properties of the cyano substituents could enhance electron injection capability. Furthermore, bithiophene-fumaronitrile (donor-acceptor) intermolecular interaction facilitates the self-assembly of the polymer chains. Organic field-effect transistors (OFETs) based on PBTSB without the electron-withdrawing group only exhibit hole transport, while OFETs based on PBTFN with cyano substituents exhibit ambipolar characteristics. The growth of PBTFN crystalline fibrils was observed with increasing annealing temperature, which enhanced hole and electron mobility. A complementary-like inverter using PBTFN with ambipolar properties exhibited good symmetry with an inverting voltage nearly half that of the power supply with a gain of 9 at VDD = 100 V. 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013. Copyright
- Jeong, Hyung-Gu,Khim, Dongyoon,Jung, Eunhwan,Yun, Jin-Mun,Kim, Juhwan,Ku, Jamin,Jang, Yun Hee,Kim, Dong-Yu
-
p. 1029 - 1039
(2013/08/24)
-
- Optimal ambipolar charge transport of thienylenevinylene-based polymer semiconductors by changes in conformation for high-performance organic thin film transistors and inverters
-
We report the synthesis and characterization of thienylenevinylene-based donor-acceptor alternating copolymers (PTVPhI-Eh and PTVPhI-C12) as highly efficient ambipolar semiconductors in a thin film transistor. These polymers exhibit significantly improved hole and electron mobilities after thermal annealing. To determine the relationship between ambipolar charge transport and thermal annealing, we investigated these polymers using various analyses such as optical spectroscopy, Raman spectroscopy, computational quantum chemical calculation, X-ray diffraction, atomic force microscopy, and ambipolar charge mobility measurements. In pristine films, the polymer chains exhibited weak intra- and interchain ordering. However, when samples were annealed at sufficiently high temperatures, they exhibited a more ordered intra- and interchain conformation. As a result, we found a strong relationship between intra- and interchain conformational changes of the polymers and corresponding ambipolar charge transport properties during thermal annealing processes. Finally, we demonstrate complementary-like ambipolar inverters using a PTVPhI-Eh polymer. The largely shifted inverting voltage was improved for the thermally annealed inverters, which exhibited large voltage gains (~40).
- Kim, Juhwan,Baeg, Kang-Jun,Khim, Dongyoon,James, David T.,Kim, Ji-Seon,Lim, Bogyu,Yun, Jin-Mun,Jeong, Hyung-Gu,Amegadze, Paul S. K.,Noh, Yong-Young,Kim, Dong-Yu
-
p. 1572 - 1583
(2013/07/28)
-
- Synthesis and characterization of soluble low-bandgap oligothiophene-[all]- S,S-dioxides-based conjugated oligomers and polymers
-
The synthesis and characterization of a new family of soluble oligothiophene-S,S-dioxides and their use as building blocks to form polythiophene-S,S-dioxides via microwave-assisted Stille coupling polymerization are described. Incorporation of the sulfone group into the polythiophene backbone leads to narrowing of the polymer bandgap, and while the energies of both Frontier orbitals in polythiophene-S,S-dioxide are lower with respect to polythiophenes, this tendency is considerably stronger for the lowest unoccupied molecular orbital than for the highest occupied molecular orbital, resulting in greater electron-accepting ability.
- Amir, Elizabeth,Sivanandan, Kulandaivelu,Cochran, Justin E.,Cowart, John J.,Ku, Sung-Yu,Seo, Jung Hwa,Chabinyc, Michael L.,Hawker, Craig J.
-
scheme or table
p. 1933 - 1941
(2012/02/15)
-
- Bithiophene-imide-based polymeric semiconductors for field-effect transistors: Synthesis, structure-property correlations, charge carrier polarity, and device stability
-
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.
-
supporting information; experimental part
p. 1405 - 1418
(2011/04/16)
-
- Synthesis and characterization of low-band-gap poly(thienylenevinylene) derivatives for polymer solar cells
-
A series of conjugated polymers containing thienylenevinylene moieties as the electron donor for polymer solar cells were synthesized through Yamamoto and Stille coupling. The structure and device properties of the homopolymer (E)-poly[2,2′-(1,2-ethenediyl)bisthiophene] (PEBT), and two donor-acceptor-type copolymers (E)-poly[2,2′-(1,2-ethenediyl)bisthiophene- alt-4,7-(2,1,3-benzothiadiazole)] (PEBTBT) and (E)-poly[2,2′-(1,2- ethenediyl)bisthiophene-alt-5,5-(4′,7′-di-2-thienyl-2′, 1′,3′-benzothiadiazole)] (PEBTTBT) were investigated. The vinylene group inserted between two thiophene rings has an important role in lowering the band gap of thienylenevinylene derivatives. In addition, the donor-acceptor-type copolymers including a benzothiadiazole unit showed even lower band gap than their own homopolymer due to intramolecular charge transfer (ICT) through their conjugated backbones. As a result, PEBT, PEBTBT and PEBTTBT showed band gaps of 1.77, 1.37 and 1.57 eV, respectively. Bulk heterojunction photovoltaic devices were fabricated using blends of the polymers with [6,6]-phenyl C71-butyric acid methyl ester (PC70BM) and PEBTBT gave the best power conversion efficiency among them, at 1.07% under AM 1.5, 100 mW cm-2. The Royal Society of Chemistry 2011.
- Jang, Soo-Young,Lim, Bogyu,Yu, Byung-Kwan,Kim, Juhwan,Baeg, Kang-Jun,Khim, Dongyoon,Kim, Dong-Yu
-
scheme or table
p. 11822 - 11830
(2011/11/06)
-
- Thiazolothiazole derivatives and organic electronic device using the same
-
The present invention relates to novel thiazolothiazole derivatives and an organic electronic device such as an organic light emitting device, an organic transistor, and an organic solar cell using the same. In the compound of the invention, various substituents are introduced to the core structure, so as to satisfy the requirements such as suitable energy levels, and electrochemical and thermal stability, and also have amorphous or crystalline property depending on the kind of the substituents, so as to satisfy the characteristics individually required for each of the devices. Further, an organic semiconductor of p-type or n-type can be fabricated by introducing various substituents to the core structure having a property of n-type. Therefore, the compound of the present invention can provide a device having higher stability.
- -
-
Page/Page column 9-10
(2010/10/03)
-
- Design, synthesis, and characterization of ladder-type molecules and polymers. air-stable, solution-processable n-channel and ambipolar semiconductors for thin-film transistors via experiment and theory
-
The design, synthesis, and characterization of new high-performance n-channel molecular/ polymeric semiconductors that are solution-processable and air-stable is of great interest for the development of p - n junctions, bipolar transistors, and organic co
- Usta, Hakan,Risko, Chad,Wang, Zhiming,Huang, Hui,Deliomeroglu, Murat K.,et al.
-
supporting information; experimental part
p. 5586 - 5608
(2009/09/25)
-
- CONJUGATED MONOMERS AND POLYMERS AND PREPARATION AND USE THEREOF
-
Disclosed are new conjugated compounds (e.g., monomers and polymers) that include ladder-type moieties which can be used for preparing semiconducting materials. Such conjugated compounds can exhibit high n-type carrier mobility and/or good current modulat
- -
-
Page/Page column 67-68
(2009/03/07)
-
- Liquid-crystalline semiconducting copolymers with intramolecular donor-acceptor building blocks for high-stability polymer transistors
-
The ability to control the molecular organization of electronically active liquid-crystalline polymer semiconductors on surfaces provides opportunities to develop easy-to-process yet highly ordered supramolecular systems and, in particular, to optimize their electrical and environmental reliability in applications in the field of large-area printed electronics and photovoltaics. Understanding the relationship between liquid-crystalline nanostructure and electrical stability on appropriate molecular surfaces is the key to enhancing the performance of organic field-effecttransistors (OFETs) to a degree comparable to that of amorphous silicon (a-Si). Here, we report a novel donor-acceptor type liquid-crystalline semiconducting copolymer, poly(didodecylquaterthiophene-a/f-didodecylbit hiazole), which contains both electron-donating quaterthiophene and electron-accepting 5,5'-bithiazole units. This copolymer exhibits excellent electrical characteristics such as field-effect mobilities as high as 0.33 cm2/V-s and good bias-stress stability comparable to that of amorphous silicon (a-Si). Liquid-crystalline thin films with structural anisotropy form spontaneously through self-organization of individual polymer chains as a result of intermolecular interactions in the liquid-crystalline mesophase. These thin films adopt preferential well-ordered intermolecular n-n stacking parallel to the substrate surface. This bottom-up assembly of the liquid-crystalline semiconducting copolymer enables facile fabrication of highly ordered channel layers with remarkable electrical stability.
- Kim, Do Hwan,Lee, Bang-Lin,Moon, Hyunsik,Kang, Hee Min,Jeong, Eun Jeong,et al.
-
supporting information; experimental part
p. 6124 - 6132
(2009/09/26)
-
- Liquid-crystalline triangle honeycomb formed by a dithiophene-based X-shaped bolaamphiphile
-
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
-
supporting information; scheme or table
p. 8014 - 8017
(2010/02/27)
-
- Synthesis and Structural Characterization of Alkyl Oligothiophenes - The First Isomerically Pure Dialkylsexithiophene
-
Regioselective bromination of alkylated bi- and ter-thiophenes affords key building blocks for the synthesis of higher, isomerically pure alkyl oligothiophenes.For all new compounds, unequivocal structural assignment is based on a detailed analysis of the fully coupled 13C, 1H NMR spectra.
- Baeuerle, Peter,Pfau, Frederike,Schlupp, Helge,Wuerthner, Frank,Gaudi, Kai-Uwe,et al.
-
p. 489 - 494
(2007/10/02)
-
- Design, Synthesis, and Control of Conducting Polymer Architectures: Structurally Homogeneous Poly(3-alkylthiophenes)
-
The full details of a facile synthesis of structurally homogeneous poly(3-alkylthiophenes) (PAT's) is presented.In three steps from 3-bromothiophene, PAT's can be made with complete regiochemical control.We define structurally homogenous as a regiochemically well-defined polymer structure that in our case contains almost exclusively head-to-tail couplings (HT-HT) (2,5-couplings between adjacent thiophene rings).By analysis of the NMR data, our poly(n-butylthiophene) (5a) contains 93percent HT-HT couplings, 98percent of the desired regiochemistry is found in poly(n-hexylthiophene) (5b), 97percent in poly(n-octylthiophene), (5c), and 95percent in poly(n-dodecylthiophene), (5d).Quenching studies on reactive intermediates and 13C NMR data also demonstrate the regiochemical purity of these materials.These PAT's show lower energy absorption maximum shifts of up to 14 nm in solution, 46 nm in the solid state, and other intense lower energy peaks with shifts of up to 129 nm (609 nm) from PAT's prepared by the usual methods.All of these data are indicative of longer mean conjugation lengths.Molecular mechanics and ab initio calculations were performed on model trimers of 3-n-alkylthiophenes and show the relationship between regiochemistry of the trimer and its resultant conformations.The results of these calculations are related to the resultant electrical conductivity in these materials.These poly(3-alkylthiophenes) provide for the first time well-defined structures for the investigation of structure-property relationships in this class of electronic and photonic materials.
- McCullough, Richard D.,Lowe, Renae D.,Jayaraman, Manikandan,Anderson, Deborah L.
-
p. 904 - 912
(2007/10/02)
-