cas 145543-83-5, 2-bromo-3-octylthiophene | Articles data

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Effect of molecular weight on electronic, electrochemical and spectroelectrochemical properties of poly(3,3″-dioctyl-2,2′5′, 2″-terthiophene)
Poly(3,3″-dioctyl-2,2′5′,2″-terthiophene), obtained from its corresponding monomer by oxidative polymerization with FeCl 3, has been fractionated into five fractions of reduced polydispersity, covering the Mn range from 1.50 kDa to 10.50 kDa (measured vs. polystyrene standards). The effect of Mn on spectroscopic, electrochemical, spectroelectrochemical and electrical transport properties has been investigated. Fractions of growing Mn show an increasing bathochromic shift of the band originating from the π-π* transition in the neutral polymer with the appearance of a clear vibrational structure for the two highest molecular fractions. The onset of oxidative doping determined from the cyclic voltammogram shifts towards lower potentials with increasing molecular weight. A similar trend is observed for doping induced near infrared bands, which shift towards lower energies (higher wavelengths) with increasing molecular weight and appear at lower potentials in spectroelectrochemical experiments. Finally, a comparison of the FET mobility in two transistors fabricated under identical conditions from polymer fractions differing in their molecular weight shows that a ca. fourfold increase of M n (from 2.40 kDa to 10.50 kDa) results in a two orders of magnitude increase in the carriers' mobility (from μsat = 4 × 10 -5 cm2 V-1 s-1 to μsat = 2 × 10-3 cm2 V-1 s-1). The obtained results underline the importance of the control of the macromolecular parameters in the preparation of electronic and electrochemical devices from poly(3,3″-dioctyl-2,2′5′,2″-terthiophene). The Royal Society of Chemistry 2006.
Pokrop, Rafal,Verilhac, Jean-Marie,Gasior, Anna,Wielgus, Ireneusz,Zagorska, Malgorzata,Travers, Jean-Pierre,Pron, Adam
p. 3099 - 3106
(2006)
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Tuning the Solid State Emission of Thin Films/Microspheres Obtained from Alternating Oligo(3-octylthiophenes) and 2,6-Bis(pyrazole)pyridine Copolymers by Varying Conjugation Length and Eu3+/Tb3+ Metal Coordination
A series of dialkynyl-functionalized oligo(3-octylthiophene)m (m = 1-7 and 9, where m is the number of thiophene units) were polymerized together with 2,6-bis(pyrazole)pyridine (BPP) to get alternating copolymers (P1-P7 and P9) with the number-average molecular weights (Mn) in the range of 5.3-11 kDa. These copolymers were further self-assembled into solid microspheres. The optical emission range of these copolymers were fine-tuned from blue to red and white by changing the conjugation length of thiophene oligomers (band gap approximately from 2.1 to 1.67 eV) and coordination of metals like Eu3+ and Tb3+ in both the solution and solid states. A white color was obtained in solution, thin film, and microsphere states with CIE (Commission Internationale de l'Eclairage) coordinates close to the values of standard white color.
Narayana, Yemineni S. L. V.,Baumgarten, Martin,Müllen, Klaus,Chandrasekar, Rajadurai
p. 4801 - 4812
(2015)
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Medium band gap conjugated polymers from thienoacene derivatives and pentacyclic aromatic lactam as promising alternatives of poly(3-hexylthiophene) in photovoltaic application
Two alternating medium band gap conjugated polymers (PBDT-TPTI and PDTBDT-TPTI) derived from 4,8-bis(4,5-dioctylthien-2-yl)benzo[1,2-b:4,5-b′]dithiophene (BDT-T) or 5,10-bis(4,5-didecylthien-2-yl)dithieno[2,3-d:2′,3′-d′]benzo[1,2-b:4,5-b′]dithiophene (DTBDT-T) with pentacyclic aromatic lactam of N,N-didodecylthieno[2′,3′:5,6]pyrido[3,4-g]thieno[3,2-c]-iso-quinoline-5,11-dione (TPTI), are synthesized and characterized. The comparative investigation of the photostabilities of the copolymers revealed that the PDTBDT-TPTI film exhibited the comparable photostability in relative to P3HT. Meanwhile, the inverted photovoltaic cells (i-PVCs) from the blend films of PBDT-TPTI and/or PDTBDT-TPTI with PC71BM, in which poly[(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] were used as cathode modifying interlayer, presented higher power conversion efficiencies (PCEs) of 5.98% and 6.05% with photocurrent response ranging from 300 nm to 650 nm in contrast with the PCEs of 4.48% for the optimal inverted PVCs from P3HT/PC71BM under AM 1.5 G 100 mW/cm2. The PCEs of the i-PVCs from PBDT-TPTI and PDTBDT-TPTI were improved to 7.58% and 6.91% in contrast to that of 0.02% for the P3HT-based i-PVCs, and the photocurrent responses of the devices were extended to 300–792 nm, when the ITIC was used as electron acceptor materials. The results indicate that the PBDT-TPTI and PDTBDT-TPTI can be used as the promising alternatives of notable P3HT in the photovoltaic application.
Gao, Peili,Tong, Junfeng,Guo, Pengzhi,Li, Jianfeng,Wang, Ningning,Li, Cheng,Ma, Xuying,Zhang, Peng,Wang, Chenglong,Xia, Yangjun
p. 85 - 95
(2018)
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1H and13C NMR study of regioregular head-to-tail oligo(octylthiophene)s and poly(octylthiophene)
The 1H and 13C signals of the aromatic region of monodisperse regioregular head-to-tail (HT) oligo(octylthiophene)s ranging from the dimer to the hexamer were assigned in CDCl3 and THF-d8. The linear dependence of proton chemical shifts on the reciprocal number of thiophenes was demonstrated in both solvents. Weak signals surrounding the main peak in the spectrum of the regioregular HT poly(octylthiophene) were assigned in CDCl3 and THF-d8 in the light of results obtained for the hexamer. In particular, the end of chain protons of the polymer could be assigned. Spin-lattice relaxation times (T1) of aromatic protons of the hexamer were measured in CDCl3 and THF-d8. We observed that T1 depended on the position of the proton along the main chain. This result was interpreted in terms of molecular motions. Copyright
Bras, Jerome,Pepin-Donat, Brigitte
p. 57 - 67
(2001)
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Organic Thin-film Solar Cells Using Benzotrithiophene Derivatives Bearing Acceptor Units as Non-Fullerene Acceptors
New star-shaped non-fullerene acceptors (5Z,5′Z,5′′Z)-5,5′,5′′-((benzo[1,2-b : 3,4-b′ : 5,6-b′′]trithiophene-2,5,8-triyltris(4-octylthiophene-5,2-diyl))tris(methaneylylidene))tris(3-octyl-2-thioxothiazolidin-4-one) (1: BTT-OT-ORD) and 2,2′,2′′-((5Z,5′Z,5′′Z)-((benzo[1,2-b : 3,4-b′ : 5,6-b′′]trithiophene-2,5,8-triyltris(4-octylthiophene-5,2-diyl))tris(methaneylylidene))tris(3-octyl-4-oxothiazolidine-5,2-diylidene))trimalononitrile (2: BTT-OT-OTZDM) with a benzotrithiophene core, alkyl-thiophen units, and acceptor units were designed and synthesized. The HOMO-LUMO levels of 1 and 2 were determined by photoemission spectroscopy and UV-Vis absorption spectroscopy. Binary blend and ternary blend bulk heterojunction (BHJ) organic solar cells with non-fullerene acceptors 1 and 2 were fabricated with the inverted device structures of glass/ITO/ZnO/active_layer/MoO3/Ag. Both binary blend BHJ solar cells with 1 and 2 show lower JSC and larger VOC values than P3HT : PCBM solar cells. On the other hand, ternary blend BHJ organic solar cells, including 10 % of 1, exhibited a larger power conversion efficiency than P3HT : PCBM solar cells because the JSC value was largely improved.
Matsumoto, Kouichi,Yamashita, Kazuhiro,Sakoda, Yuuki,Ezoe, Hinata,Tanaka, Yuki,Okazaki, Tatsuya,Ohkita, Misaki,Tanaka, Senku,Aoki, Yuki,Kiriya, Daisuke,Kashimura, Shigenori,Maekawa, Masahiko,Kuroda-Sowa, Takayoshi,Okubo, Takashi
p. 4620 - 4629
(2021/09/10)

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
(2021/11/03)

Synthesis and characterization of new D-π-A and A-π-D-π-A type oligothiophene derivatives
In this work, we present a series of newly synthesized conjugated oligothiophene derivatives, with different numbers of central thiophene units, and different donor/acceptor architectures. Electrochemical and spectroscopic data have also been reported. We used thiophene or bithiophene as central donor core units, 3-octylthiophenes as π-bridge and solubilizing sub-units, and ethyl cyanoacetate or rhodanine moieties as acceptor end groups, in order to get D-π-A and A-π-D-π-A molecular architectures. The length of the synthesized oligothiophenes ranges from three to eight thiophene units, a variety that is sufficient to put in evidence different optical and electrochemical characteristics as well as semiconducting characteristics. Oligothiophene compounds can be regarded not only as models for the study of structure-property relationships relative to polythiophenes, but also they present a large number of applications in the field of organic electronics (i.e.: as donors in bulk-heterojunction solar cells and hole-transporting layer materials in perovskite solar cells, among others).
Pandolfi, Fabiana,Rocco, Daniele,Mattiello, Leonardo
supporting information
p. 3018 - 3025
(2019/03/21)

TRIPHENYLAMINE COMPOUNDS, POLYMERS MADE THEREFROM AND ELECTROCHROMIC DEVICE COMPRISING THE SAME
The present invention relates to a triphenylamine compound, to a polymer thereof and to an electrochromic device comprising the same, and specifically, to a triphenylamine compound represented by the chemical formula (1), to a polymer thereof and to an electrochromic device comprising the same. In the chemical formula (1), R, R1, R2, R3, R4, and R5 are as defined in claim 1. The present invention also provides a triphenylamine-based polymer capable of forming a thin film having uniform surface and exhibiting excellent reversibility in the electrochromic characteristics.COPYRIGHT KIPO 2018
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Paragraph 0196; 0199; 0204-0206

(2018/05/03)

Synthesis and characterization of triphenylamine-based polymers and their application towards solid-state electrochromic cells
Four novel triphenylamine-based polymers, PJK1, PJK2, PJK3 and PJK4 were successfully synthesized and fully characterized by 1H NMR, UV-VIS spectroscopy, cyclic voltammetry (CV), GPC and spectroelectrochemistry. These polymers are easily soluble in many common organic solvents, which make them appropriate for film deposition via spray-coating. We fabricated electrochromic cells comprising ITO-coated glass/polymer/gel electrolyte/ITO-coated glass and patterned the color change by applying direct current with different voltages. We report herein color changes, from the neutral to oxidized form as follows: for PJK1, orange to dark green; for PJK2, light yellow to reddish brown; for PJK3, light blue to grey; and for PJK4, green to bluish green. The majority of the copolymers exhibited very good thermal stabilities, as evidenced by less than a 5% weight loss in temperatures exceeding 400 °C. To further characterize, we simulated the electrochemical and optical properties, which are good agreement with the experimental data.
Jeong, Jaemyeng,Kumar, Rangaraju Satish,Naveen, Mergu,Son, Young-A.
p. 78984 - 78993
(2016/09/09)

The photoelectric material preparation
A photoelectric active compound selected from the compounds having general formulas (1)-(3), and preparation method and uses thereof.
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Paragraph 0147-0150

(2016/12/01)

SUBSTITUTED NAPHTHYRIDINES AS ACCEPTOR MOLECULES FOR ELECTRONIC DEVICES
The present invention provides the compounds of formula (1) wherein p is 1, 2, 3, 4, 5 or 6, and10 Ar1 is at each occurrence a 5 to 9 membered heteroaromatic moiety, which may be substituted with one or more substituents independently from each other selected from the group consisting of C1-20-alkyl, O-C1-20-alkyl, C(O)-C1-20-alkyl, C(O)-O-C1-20-alkyl, phenyl, F, Cl and Br, wherein C1-20-alkyl, C1-20-alkyl, O-C1-20-alkyl, C(O)-C1-20-alkyl and C(O)-O-C1-20-alkyl may be substituted with one or more substituents independently from each other selected from the group consisting of F, Cl, Br and phenyl, wherein phenyl may be substituted with one or more substituents independently from each other selected from the group consisting of F, Cl, Br and C1-10-alkyl, and electronic devices comprising these compounds.
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(2015/02/25)

Design, synthesis and photophysical properties of A-D-A-D-A small molecules for photovoltaic application
A series of linear-conjugated small molecule compounds featured with the acceptor-donor-acceptor-donor-acceptor (A-D-A-D-A) structure were designed, synthesized and characterized. The films of the compounds showed a broad UV-Vis absorption range of 300-800 nm with high molar absorption coefficient of more than 1.0 × 104 cm-1. Their hole-mobility can be as high as 1.0 × 10-3 cm2 V-1 s-1. The compounds have a compatible HOMO energy level of -5.0 eV to PC71BM and a high solubility up to 20 mg mL-1 in chloroform. Therefore, compounds can blend with PC71BM in the chloroform and form an active layer for a photovoltaic cell device by spin-coating of the blend solution. A maximum power conversion efficiency of 3.2% was achieved with the DERH3TT solar cell device. These results indicate that the A-D-A-D-A small molecules with electron-withdrawing dyes as terminals are promising candidates for the high efficiency solution processed organic photovoltaic cells.
Yan, Weibo,Zhang, Qian,Qin, Qingsong,Ye, Senyun,Lin, Yuanwei,Liu, Zhiwei,Bian, Zuqiang,Chen, Yongsheng,Huang, Chunhui
p. 99 - 108
(2015/06/08)

Photoelectric materials and preparation thereof
Receptor type oligothiopene compounds, methods of preparing the compounds, and use of the compounds in photoelectric materials.
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Page/Page column 63

(2015/11/30)

Development of novel n-Type materials based on benzothiadiazole derivatives for organic photovoltaics: Effects of acceptor terminal substituents
Novel n-type materials of BTD-CN (1) and BTD-CF3 (2) were synthesized for organic photovoltaics. Both materials show approximately the same HOMO-LUMO level and position of absorption peaks. However, the organic photovoltaic performance of a device with 1 is clearly higher than that with 2. In this paper, we discuss the effects of terminal substituents on film morphology, crystallinity, and photovoltaic performance. The results suggest that cyano-modified benzothiadiazole is useful because of its crystallinity, carrier recombination, and series resistance.
Shibata, Yosei,Kono, Takahiro,Usui, Hiroyo,Yoshida, Yuji
supporting information
p. 680 - 682
(2015/05/27)

Quinoxalin compd., electron-donating organic material using the same, and photovoltaic element material for a photovoltaic element
PROBLEM TO BE SOLVED: To provide a photovoltaic element having high photovoltaic conversion efficiency. SOLUTION: There is provided a quinoxaline compound satisfying requirements that (a) it contains a quinoxaline skeleton and an oligothiophene skeleton, (b) it has a band gap (Eg) of ≤1.8 eV and (c) the level of highest occupied molecular orbital (HOMO) is ≤-4.8 eV. COPYRIGHT: (C)2010,JPOandINPIT
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Paragraph 0060; 0064

(2016/12/16)

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)

Dithiophene based X-shaped bolaamphiphiles: Liquid crystals with single wall honeycombs and geometric frustration
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
p. 10921 - 10931,11
(2020/09/15)

Phenacyl-thiophene and quinone semiconductors designed for solution processability and air-Stability in high mobility n-channel field-effect transistors www.chemeurj.org
Electron-transporting organic semiconductors (n-channel) for fieldeffect transistors (FETs) that are processable in common organic solvents or exhibit air-stable operation are rare. This investigation addresses both these challenges through rational molecular design and computational predictions of n-channel (FETs) air-stability. A series of seven phenacyl-thiophene-based materials are reported incorporating systematic variations in molecular structure and reduction potential. These compounds are as follows: 5,5?-bis(perfluorophenylcarbonyl)-2,2′:5′,-2″:5″, 2?-quaterthiophene (1), 5,5?-bis-(phenacyl)-2,2′;5′, 2″: 5″,2?-quaterthiophene (2), poly[5,5?- (perfluorophenac-2-yl)-4′,4″-dioctyl-2,2':5',2":5", 2'"-quaterthiophene) (3), 5,5?-bis(perfluorophenacyl)-4,4?- dioctyl-2,2′:5′,2″:5″,2?-quaterthiophene (4), 2,7-bis((5-perfluorophenacyl)thiophen-2-yl)-9,10phenanthrenequinone (5), 2,7-bis[(5phenacyl)thiophen-2-yl]-9,10-phenanthrenequinone (6), and 2,7-bis(thiophen-2-yl)-9,10-phenanthrenequinone, (7). Optical and electrochemical data reveal that phenacyl functionalization significantly depresses the LUMO energies, and introduction of the quinone fragment results in even greater LUMO stabilization. FET measurements reveal that the films of materials 1, 3, 5, and 6 exhibit n-channel activity. Notably, oligomer 1 exhibits one of the highest, μe (up to ≈0.3 Cm 2V-1S-1) values reported to date for a solutioncast organic semiconductor; one of the first n-channel polymers, 3, exhibits μe ≈ 10-6 Cm2V -1S-1 in spin-cast films (μc = 0.02 cm 2 V-1S-1 for drop-cast 1:3 blend films); and rare air-stable n-channel material 5 exhibits n-channel FET operation with μe = 0.015 cm2V-1s-1, while maintaining a large Ion:off= 106 for a period greater than one year in air. The crystal structures of 1 and 2 reveal close herringbone interplanar π-stacking distances (3.50 and 3.43 A, respectively), whereas the structure of the model quinone compound, 7, exhibits 3.48 A cofacial π-stacking in a slipped, donor-acceptor motif.
Letizia, Joseph A.,Cronin, Scott,Ortiz, Rocio Ponce,Facchetti, Antonio,Ratner, Mark A.,Marks, Tobin J.
experimental part
p. 1911 - 1928
(2010/06/16)

THIAZOLOTHIAZOLE DERIVATIVE
A thiazolothiazole derivative is represented by the following Formula (I). In Formula (I), each R1 independently represents a straight chain alkyl group having 3 to 20 carbon atoms, a straight chain alkoxy group having 3 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, or a branched alkoxy group having 3 to 20 carbon atoms; and each R2 independently represents a hydrogen atom, a straight chain alkyl group having 1 to 20 carbon atoms, a straight chain alkoxy group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, or a branched alkoxy group having 3 to 20 carbon atoms.
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(2010/06/16)

Donor-acceptor polymers incorporating alkylated dithienylbenzothiadiazole for bulk heterojunction solar cells: Pronounced effect of positioning alkyl Chains
4,7-Di(thiophen-2-yl)benzothiadiazole (DTBT) has been used to construct a number of donor-acceptor low band gap polymers for bulk heterojunction (BHJ) photovoltaics with high efficiency numbers. Its strong tendency to π-stack often leads to polymers with low molecular weight and poor solubility, which could potentially be alleviated by anchoring solubilizing chains onto the DTBT unit. A systematic study of the effect of positioning alkyl chains on DTBT on properties of polymers was implemented by investigating a small library of structurally related polymers with identical conjugated backbone. This series of donor-acceptor polymers employed a common donor unit, benzo[2,1-b:3,4-b′] dithiophene (BDT), and modified DTBT as the acceptor unit. Three variations of modified DTBT units were prepared with alkyl side chains at (a) the 5-and 6-positions of 2,1,3-benzothiadiazole (DTsolBT), (b) 3-positions of the flanking thienyl groups (3DTBT), and (c) 4-positions (4DTBT), in addition to the unmodified DTBT. Contrary to results from previous studies, optical and electrochemical studies disclosed almost identical band gap and energy levels between PBDT-4DTBT and PBDT-DTBT. These results indicated that anchoring solubilizing alkyl chains on the 4-positions of DTBT only introduced a minimum steric hindrance within BDT-DTBT, maintaining the extended conjugation of the fundamental structural unit (BDT-DTBT). More importantly, the additional high molecular weight and excellent solubility of PBDT-4DTBT led to a more uniform mixture with PCBM, with better control on the film morphology. AU these features of PBDT-4DTBT led to a significantly improved efficiency of related BHJ solar cells (up to 2.2% has been observed), triple the efficiency obtained from BHJ devices fabricated from the "conventional" PBDT-DTBT (0.72%). Our discovery reinforced the importance of high molecular weight and good solubility of donor polymers for BHJ solar cells, in addition to a low band gap and a low HOMO energy level, in order to further enhance the device efficiencies.
Zhou, Huaxing,Yang, Liqiang,Xiao, Shengqiang,Liu, Shubin,You, Wei
scheme or table
p. 811 - 820
(2011/10/08)

Palladium-catalyzed coupling reactions towards the synthesis of well-defined thiophene-oligomers
Heck- and Ullmann-type palladium-catalyzed reactions were used in order to perform the synthesis of 3′,4″-dioctyl-2,2′, 5′2″,5″,2′″-tetrathienyl. The desired oligothiophene was synthesized in five steps with a total yield of 38% by a Heck-type reaction of bromo-derivatives and a yield of 45% by an Ullmann-type reaction of iodo-precursors.
Hassan, Jwanro,Gozzi, Christel,Schulz, Emmanuelle,Lemaire, Marc
p. 280 - 283
(2007/10/03)

Highly conjugated poly(thiophene)s - Synthesis of regioregular 3-alkylthiophene polymers and 3-alkylthiophene/thiophene copolymers
Tributyltin derivatives of 2-bromo-3-octylthiophene and 5-bromo-4-octyl-2,2′-bi(thiophene) have been selectively prepared. Condensation reactions in the presence of Pd2(dba)3(CHCl3)/4 PPh3 led to high yields (ca. 90%) of regioregular poly(3-octylthiophene) (Mw = 21.4 × 104, Mw/Mn = 1.48) and poly[4-octylbi(thiophene)] (Mw = 3.8 × 104, Mw/Mn = 1.1). The regioregularity of the head-to-tail (HT) coupling has been determined by 1H NMR, which showed HT > 95% for poly(3-octylthiophene) and HT > 90% for the new poly[4-octylbi(thiophene)]. The conjugation properties of these materials have been characterized by FT-IR and UV/Vis spectroscopy. Compared to the corresponding random polymers, the absorption maxima of the new regular polymers are shifted to higher wavelengths (λmax = 448 and 466 nm, respectively). The mean conjugation length increases with increasing regioregularity of the coupling and with fewer substituents along the conjugated chain. The electroactive properties of the materials have also been studied. The new poly[4-octylbi(thiophene)] shows an oxidation peak at a low potential, and, compared to poly(3-octyl-thiophene), a reduction peak is also observed at a lower potential indicating a higher electron affinity. Both polymers exhibit reversible blue-red electrochromic behavior associated with the reversible redox properties.
Lere-Porte, Jean-Pierre,Moreau, Joel J. E.,Torreilles, Christophe
p. 1249 - 1258
(2007/10/03)

Novel photoluminescent polymers containing oligothiophene and m-phenylene-1,3,4-oxadiazole moieties: Synthesis and spectroscopic and electrochemical studies
Three conjugated polymers containing oligothiophene units (from one to three thiophene rings) and aromatic 1,3,4-oxadiazole moieties have been successfully synthesized. The polymer structures were characterized and confirmed by 1H and 13C NMR, FT-IR, and elemental analysis. Thermogravimetric analysis demonstrated that the polymers are highly thermal stable. Tunable absorption (from 342 to 428 nm) and fluorescence (from 411 to 558 nm) properties of polymers were observed: The electrochemical investigation indicated that the LUMO and HOMO energy levels of the new polymers could be adjusted. It was also revealed by the electrochemical analysis that the polymers have good charge injection properties for both p-type and n-type charge carriers, as well as good color tunable luminescence and film-forming properties, which makes them potentially useful for fabricating efficient light-emitting devices.
Meng,Huang
p. 3894 - 3901
(2007/10/03)

Study of an efficient and selective bromination reaction of substituted thiophenes
Bromination in concentrated solutions of substituted thiophenes in acetic acid with NBS at room temperature was studied. Under the conditions, bromination readily took place with high regioselectivity at the 2-ring positions, > 99%. The developed method was demonstrated to be suitable for multimolar preparations.
Hoffmann, Kenneth J.,Carlsen, Per H. J.
p. 1607 - 1610
(2007/10/03)

Synthesis and infrared properties of ethylenedioxythiophene and octylthiophene based copolymers
The control of the structural parameters and doping conditions of PATs lead to quasimetallic materials. We have developed the synthesis of copolymers and PAT to enhance the metallic properties with conservation of the solubility.
Buvat,Hourquebie
p. 1180 - 1183
(2007/10/03)

The routes towards calibrated and regioregular poly(3-octylthiophene) conducting gels: Preparation of the basic mesh
In order to study the transport properties-connectivity relationship in conducting networks, we have deeded to prepare calibrated fully conjugated gels. Four series of statistical poly(octylthiophene) gels have already been obtained. We now plan to control the absolute length and the regioregularity of the chain segments defined by adjacent crosslinks. These segments consist of n (n≥l) sexi(3-octyl)thiophene. We have improved the step-by-step preparation of the regioregular sexioctylthiophene. We have further caracterized all the oligomers (from bithiophene to sexithiophene). The regioregular sexioctylthiophene was then coupled to a 1, 3, 5 tribromobenzene. The molecule thus obtained is the basic unit of the gels.
Bras,Guillerez,Pepin-Donat
p. 1161 - 1164
(2007/10/03)

Palladium catalyzed cross-coupling reactions of difunctional derivatives Bu3SnArBr. Synthesis of regioregular poly(3-alkylthiophenes) and poly(4- alkyl 2,2'-bithiophenes) with high molecular weights
The Pd catalyzed organometallic coupling reactions of difunctional derivatives Bu3SnArBr has been used to prepare regioregular poly(3-alkyl thiophenes) and poly(4-alkyl 2,2'-bithiophenes) with high molecular weight.
Lere-Porte,Moreau,Torreilles
p. 1250 - 1253
(2007/10/03)

Effect of chain extension on the electrochemical and electronic properties of π-conjugated soluble thienylenevinylene oligomers
Thienylenevinylene oligomers (nTVs) containing up to 10 thiophene rings and bearing solubilizing hexyl groups at the α-position of the end thiophene rings or octyl or dibutyl chains at the 3-position or the 3- and 4-positions of the thiophene rings have been synthesized by a combination of formylation reaction, Wittig-Horner olefination, and McMurry dimerization. Owing to the good solubility imparted by alkyl chains, the electrochemical behavior of nTVs has been analyzed for the first time. Chain extension leads to;a negative shift of the peak potentials corresponding to the formation of the cation radical and dication and to a decrease of their difference. For the octamers the dication is formed directly through a two-electron transfer while the system can be reversibly charged up to the tetracationic state. Electronic absorption spectra show the expected bathochromic shift of λ(max) and decrease of the HOMOLUMO gap with extension of the conjugation length. Thus, solution-cast films of octamers exhibit band-gap values electrochemical and optical data to infinite chain length suggests that the oxidation potential and:intrinsic band gap of a defect-free PTV could be significantly smaller than the present experimental values.
Elandaloussi, El Hadj,Frère, Pierre,Richomme, Pascal,Orduna,Garin,Roncali, Jean
p. 10774 - 10784
(2007/10/03)

Facile, Regioselective Synthesis of Highly Solvatochromic Thiophene-Spaced N-Alkylpyridinium Dicyanomethanides for Second-Harmonic Generation
The facile and clean synthesis of a novel class of highly solvatochromic chromophores 1 is reported. Compounds 1 are push-pull systems containing a negatively charged dicyanomethanide as a donor group and a positively charged N-alkylpyridinium as an acceptor group. The terminal polar functions are spaced by a thiophene-based moiety containing one or two heterocyclic rings and none, one, or two ethylene bridges. Chromophores 1 have been obtained through a general synthetic scheme involving, as the last step, the 100% regioselective alkylation of the precursor bidentate anions 2, where two competing nucleophilic sites, one neutral at the pyridic nitrogen and one anionic at the carbanionic carbon of the dicyanomethanide group, are present. The unprecedented highly regioselective attack of the alkylating agent onto the neutral pyridic nitrogen rather than the highly charged carbanionic carbon has been also confirmed in the case of the intermolecular competition. Multinuclear (13C and 15N) NMR spectroscopy has been used to investigate the structure and the extent of intramolecular charge transfer in 1, which are shown to exist in the ground state as highly charge-separated zwitterionic systems. Experimental results are discussed and compared with semiempirical (PM3) computations. The solvatochromic response of compounds 1, among the highest ever reported in the literature for similar systems, candidates this class of compounds as very attractive active components of nonlinear optical materials.
Abbotto, Alessandro,Bradamante, Silvia,Facchetti, Antonio,Pagani, Giorgio A.
p. 5755 - 5765
(2007/10/03)

Soluble thienylenevinylene oligomers end-capped with 1,3-dithiole-2-ylidene groups
The synthesis of thienylenevinylene oligomers end-capped with 1,3-dithiole-2-ylidene is described. CV analysis shows that these compounds can be oxidized up to their tetracationic state within a narrow potential window.
Elandaloussi, El Hadj,Frere, Pierre,Roncali, Jean
p. 6121 - 6124
(2007/10/03)

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)