- Fine-tuning the solid-state ordering and thermoelectric performance of regioregular P3HT analogues by sequential oxygen-substitution of carbon atoms along the alkyl side chains
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Conjugated polymers in thin films tend to orient their backbones with respect to substrates through self-assembly when processed from a solution. The molecular packing orientation and crystallinity of polymer crystals have been found to play a critical role in terms of their electrical performance. Taking advantage of the shorter bond length and the smaller rotation energy of the CH2-O bond than those of the CH2-CH2 bond in an alkyl chain, a side-chain engineering strategy is reported, which involves sequential oxygen-substitution of the carbon atoms from the γ position outwards along the hexyls in regioregular poly(3-hexylthiophene) (RR-P3HT). The subtle disparity between the CH2-O and CH2-CH2 bonds is found to enable fine tuning of the solid-state organization of the corresponding RR-P3HT analogues, namely poly(3-(2-propoxyethyl)thiophene) (P3POET), poly(3-(3-ethoxypropyl)thiophene) (P3EOPT) and poly(3-(4-methoxybutyl)thiophene) (P3MOBT). The evolution of film microstructures is observed when doping with FeCl3 in nitromethane at room temperature, and so is their thermoelectric performance. The highest power factor of 19 μW m-1 K-2 was observed for the doped P3POET film, which presents a dominant edge-on orientation with the strongest crystallinity and the closest π-π stacking. At the doping time corresponding to the optimized power factors (PFs) for each polymer, the doped P3POET film maintains both relatively high Seebeck coefficient (S) and electrical conductivity (σ) close to their maximum values, while the other polymers show either higher S and much lower σ (P3HT) or higher σ but much lower S (P3EOPT and P3MOBT). The square dependence of the PFs on S together with higher σ amplifies the power factor value of P3POET, which is almost 2 times those of the other polymers (11-13 μW m-1 K-2).
- Chen, Liangjun,Liu, Wei,Yan, Yonggao,Su, Xianli,Xiao, Shengqiang,Lu, Xinhui,Uher, Ctirad,Tang, Xinfeng
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- Novel crown-containing 3-styryl derivatives of oligothiophenes: Synthesis, structure, and optical and electrochemical characteristics
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A method for the synthesis of the 3-substituted polythiophene derivatives including two crown-containing styryl fragments was proposed. The optical properties of the obtained compounds are characterized by the presence of intense absorption and fluorescence bands. The oxidation to the thiophene derivatives involves the crown-containing styryl fragment and should be sensitive to the presence of the metal cation in the crown ether cavity.
- Lukovskaya,Bobyleva,Fedorova,Fedorov,Anisimov,Didane,Brisset,Fages
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- Thallium(III) Trifluoroacetate-Trifluoroacetic Acid in the Chemistry of Polythiophenes. 2. Treatment of 3-Alkylthiophenes and Electron Paramagnetic Resonance Results
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The treatment of thiophene and 3-alkylthiophenes with thallium(III) trifluoroacetate (TTFA) in trifluoroacetic acid (TFA) gives insoluble and dark powdery solids with oxygen content and electrical conductivities ranging from 10-4 to 10-6 Ω-1 cm-1. Polar and short fractions are negligible. All of them show semiconductivity (10-3Ω-1 cm-1) when doped in iodine atmosphere. Electron paramagnetic resonance (EPR) spectra of either as-synthesized or I2-treated solids display characteristic single and broad lines (ΔHPP, 1.84-7.4 G) with Lorentzian shapes and g-values in the range 2.0028-2.0038. Infrared spectra show characteristic C-H out-of-plane deformations (780 cm-1 for polythiophene and 820-825 cm-1 for poly(3-alkylthiophenes)) in addition to a strong peak at 1650-1690 cm-1 which has not been conclusively assigned. EPR spectra of some disubstituted and tetrasubstituted 2,2′-bithiophene radical cations have been observed and their g-values and coupling constants assigned when the corresponding parent compounds are photolyzed with ultraviolet light in TFA. Photolysis of 3-alkylthiophenes in TFA in the EPR instrument gave the radical cations of 4,4′-dialkyl-2,2′-bithiophenes. In no case, were EPR signals of the isomeric 3,3′-dialkyl- or 3,4′-dialkyl-2,2′-bithiophene radical cations observed, indicating that dimerization of 3-alkylthiophenes occurs through the less sterically hindered 5-position. The presence of two doublet species corresponding to both conformers, syn and anti, in the radical cations is associated with a large barrier to rotation about the C(2)-C(2′) bond.
- Tormo, Jordi,Jesus Moreno,Ruiz, Jordi,Fajari, Lluis,Julia, Luis
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- One-step synthesis of a thienylenepyridazinylenethienylene-based coil-rod-coil copolymer with enhanced emission and improved fluorescence stability
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A new coil-rod-coil copolymer is synthesized via Sonogashira coupling using one-step methodology. The copolymer PEG-OEPETPT-PEG constitutes of poly(ethylene glycol) (PEG) as the coil block, and oligo[p- (ethynylenephenyleneethynylene)-alt-(thienylenepyridazinylenethienylene)] (OEPETPT) as the rod segment. The conjugated polymer PEPETPT with the same conjugated building blocks is also synthesized for comparison. The structures of both polymers are confirmed by NMR, combined with other characterizations. PEG-OEPETPT-PEG has a 12 nm blue-shift in the emission maximum compared with that of PEPETPT, and a higher quantum yield of fluorescence in THF. PEG-OEPETPTE-PEG tolerates up to 20% water content in H2O/THF mixed solvent without significantly changing the emission wavelength and intensity, while the fluorescence of PEPETPT is dramatically quenched by a very small quantity of water. Further photophysical studies about these two polymers indicate that the introduction of PEG coils onto the conjugated block retards the water-induced-aggregation and therefore improves the fluorescence stability of PEG-OEPETPT-PEG. Copyright
- Wu, Wei,Xu, Haibo,Shen, Dezhi,Qiu, Tian,Fan, Li-Juan
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- Bithiophene with winding vine-shaped molecular asymmetry. Preparation, structural characterization, and enantioselective synthesis
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Preparation of 2,2-bithiophene derivatives bearing ?-alkenyl groups at the 3,3-positions and ring-closing metathesis reactions of the obtained compound were performed. The reaction of bithiophene bearing 3-butenyl substituents 1 with 5mol% Grubbs 1st generation catalyst underwent ring-closing metathesis (RCM) to afford the cyclized product 7 showing winding vine-shaped molecular asymmetry in up to 88% yield. Enantioselective RCM was also achieved by the use of chiral SchrockHoveyda molybdenum-alkylidene catalyst in up to 87% ee.
- Toyomori, Yuka,Tsuji, Satoru,Mitsuda, Shinobu,Okayama, Yoichi,Ashida, Shiomi,Mori, Atsunori,Kobayashi, Toru,Miyazaki, Yuji,Yaita, Tsuyoshi,Arae, Sachie,Takahashi, Tamotsu,Ogasawara, Masamichi
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- Formation of a trithia[5]helicene in an unexpected photoreaction of a methyl-substituted bis(dithienylethenyl)thiophene through a double sequence of 6π-electrocyclization/aromatization (dehydrogenation/demethylation)
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Photochemical reactions of 2,5-bis[2,2-di(thien-2-yl)ethenyl]thiophene (1a) and its tetramethyl derivative 1b, under direct photoexcitation, and photoinduced electron-transfer conditions, were studied. Our initial prediction was that 1b would undergo a photoreaction as part of a reversible photochromic system, while a reaction of its non-methyl substituted analog 1a would undergo a typical double sequence of 6π-electrocyclization (6π-EC)/aromatization (AR) (double dehydrogenation, [sbnd]2H) to give 7,11-di(thien-2-yl)trithia[5]helicene (2a). In fact, we observed that photoirradiation of 1b leads to formation of the 7,11-bis(3-methylthien-2-yl)trithia[5]helicene (2b). In this process, 2b is formed via a double sequence of 6π-EC/AR (dehydrogenation/demethylation, [sbnd]H/[sbnd]Me). Moreover, the yield of formation of 2b is much higher than that of 2a, which reacts through a double sequence of 6π-EC/AR ([sbnd]2H). Thus, this photochemically-induced paradoxical cascade reaction based on the newly uncovered reactivity serves as an efficient method to construct the trithia[5]helicene framework.
- Yamamoto, Atsushi,Matsui, Yasunori,Ohta, Eisuke,Ogaki, Takuya,Sato, Hiroyasu,Furuyama, Taniyuki,Kobayashi, Nagao,Mizuno, Kazuhiko,Ikeda, Hiroshi
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- Influence of incorporating different electron-rich thiophene-based units on the photovoltaic properties of isoindigo-based conjugated polymers: An experimental and DFT study
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A series of novel donor-acceptor conjugated alternating copolymers based on the isoindigo acceptor moiety have been designed, synthesized, and characterized, in order to explore the potential of isoindigo for efficient donor materials with high photovoltages in solar cells. We have systematically investigated and discussed the effect of combining different electron-rich thiophene-based units on the structural, optical, electronic, and photovoltaic properties of the resulting polymers. Morphological studies and quantum-chemical calculations are carried out to gain insights into the different properties. The power conversion efficiencies (PCEs) of the solar cells based on these polymers are increased step by step by over 3-fold through a rational structural modification. Among them, PBDTA-MIM shows a PCE of 5.4%, which is to our knowledge the best result achieved among isoindigo-based polymers for solar cells combined with PC61BM as the acceptor using the conventional device configuration. Our results further emphasize the use of isoindigo as an effective acceptor unit and highlight the importance of carefully choosing appropriate chemical structure to design efficient donor-acceptor polymers for organic solar cells. In addition, the resulting low optical gaps, the promising PCEs with PC61BM as the acceptor, and the good open-circuit voltages (up to 0.8 V) synergistically demonstrate the potential of this class of polymers as donor materials for bottom subcells in organic tandem solar cells.
- Zhuang, Wenliu,Bolognesi, Margherita,Seri, Mirko,Henriksson, Patrik,Gedefaw, Desta,Kroon, Renee,Jarvid, Markus,Lundin, Angelica,Wang, Ergang,Muccini, Michele,Andersson, Mats R.
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- 2-AMINO-N-(AMINO-OXO-ARYL-LAMBDA6-SULFANYLIDENE)ACETAMIDE COMPOUNDS AND THEIR THERAPEUTIC USE
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The present invention pertains generally to the field of therapeutic compounds. More specifically the present invention pertains to certain 2-amino-N-(amino-oxo-aryl-λ6- sulfanylidene)acetamide compounds (referred to herein as ANASIA compounds) that, inter alia, inhibit (e.g., selectively inhibit) bacterial aminoacyl-tRNA synthetase (aaRS) (e.g., bacterial leucyl-tRNA synthetase, LeuRS). The present invention also pertains to pharmaceutical compositions comprising such compounds, and the use of such compounds and compositions, both in vitro and in vivo, to inhibit (e.g., selectively inhibit) bacterial aminoacyl-tRNA synthetase; to treat disorders that are ameliorated by the inhibition (e.g., selective inhibition) of bacterial aminoacyl-tRNA synthetase; to treat bacterial infections; etc.
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(2021/06/26)
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- A study on regulating the conjugate position of NLO chromophores for reducing the dipole moment and enhancing the electro-optic activities of organic materials
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In order to improve the first-order hyperpolarizability (β) of the chromophore and transform it into a high macroscopic electro-optic activity, a series of novel second-order nonlinear optical chromophores with different push-pull electron groups introduced on the thiophene π-conjugate bridge for tuning the shape and dipole moment (μ) of chromophores were designed and synthesized. These chromophores are based on the same thiophene π-conjugated bridge, where the donor (N,N-diethylaniline) and acceptor (2-(3-cyano-4,5,5-trimethylfuran-2(5H)-ylidene)malononitrile or malononitrile) are linked to positions 2 and 3 of thiophene, respectively, affording a boomerang-like shape instead of a rod-like shape. Besides, an electron-poor group, Br (bromine atom), or an electron-rich group, DEA (N,N-diethylaniline), as an auxiliary acceptor or donor are linked to position 5 of thiophene. In addition, all chromophores showed good thermal stability as per the results from the DSC and TGA analysis. Through UV-vis analysis and DFT calculation, it has been concluded that chromophores with additional electron-rich groups as auxiliary donors display better intermolecular charge-transfer (ICT) absorption and lower HOMO-LUMO energy gaps (ΔE). Furthermore, the boomerang-like chromophore with the same push-pull structure shows a smaller dipole moment (μ) and β value than the traditional FTC. The poling results of guest-host EO polymers FTC/APC, FTC-H/APC, FTC-Br/APC and FTC-DEA/APC with the same number density afford r33 values of 17 pm V-1, 11 pm V-1, 10 pm V-1 and 25 pm V-1, respectively. Although the β value of FTC-DEA is smaller than that of FTC, the r33 value of FTC-DEA (25 pm V-1) is 47% greater than that of FTC (17 pm V-1) under the same number density. Hence, the above-mentioned results indicated that regulating the conjugate position of chromophores can efficiently decrease the dipole moment of the chromophores, weakening the dipole-dipole interactions and thereby enhancing the macroscopic electro-optical activity of poled polymers. These results indicate the potential application of these novel chromophores in electro-optical devices.
- Zhang, Hui,Tian, Yanxin,Bo, Shuhui,Xiao, Linghan,Ao, Yuhui,Zhang, Ji,Li, Ming
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p. 1380 - 1390
(2020/02/11)
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- Targeted and selective HOMO energy control by fine regulation of molecular planarity and its effect on the interfacial charge transfer process in dye-sensitized solar cells
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In terms of the in-depth development of organic dyes, targeted and selective energy control is becoming a more and more important objective. Herein, four indoline sensitizers based on D-π-A-π-A construction were designed and synthesized with exactly the same donor and acceptor segments. Their molecular planarity was regulated by introducing various side chains into donor bridges. Interestingly, along with an improvement of planarity at a donor bridge, the HOMO levels of the dyes lift gradually, and more importantly, their LUMO levels remain at around the same value. Besides, better molecular planarity is obviously preferred to obtain higher charge injection efficiency but, an overly planar molecule may cause an overly high HOMO level, leading to poor dye regeneration efficiency. Furthermore, an appropriate side chain also restrains charge recombination to some extent, while an overly large side chain gives more chance for I3- to recombine with charge in the conduction band. Accordingly, our results demonstrated that regulation of planarity at a donor bridge not only provides targeted and selective control of the HOMO of the dye, but also enable fine adjustment with multiple interfacial charge transfer processes. Molecular planarity deserves to play an important role in the design of organic dyes, providing a significant strategy for the further development of organic sensitizers.
- Zhang, Fengyu,Wang, Ran,Wang, Yajun,Zhang, Xiaomin,Liu, Bo
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p. 6256 - 6264
(2019/04/04)
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- Nosyl (2-Nitrobenzenesulfonyl) Annulation Strategy toward Winding Vine-Shaped Bithiophenes
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Winding vine-shaped bithiophene was synthesized through the nosyl (2-nitrobenzenesulfonyl) cyclization protocol. The reaction of bithiophene bearing bromomethyl groups at the 3,3′-positions with nosylated 1,2-ethylenediamine in the presence of potassium carbonate afforded the annulated product in excellent yield. The obtained bithiophene was found to contain a 10-membered ring, which was confirmed by X-ray analysis. The related nosyldiamine bearing a tri- or tetramethylene group also reacted in a similar manner, affording an 11- or 12-membered macrocycle, respectively.
- Ashida, Shiomi,Tanaka, Naoki,Ito, Yukiko,Matsuoka, Mitsuru,Hashimoto, Takayoshi,Okano, Kentaro,Miyazaki, Yuji,Kobayashi, Tohru,Yaita, Tsuyoshi,Mori, Atsunori
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p. 14797 - 14801
(2018/12/11)
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- A 2 - bromo - 3 - thiophene carboxylic acid intermediates of the synthesis method (by machine translation)
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The invention relates to 2 - bromo - 3 - thiophenecarboxylic acid synthesis method, comprises the following synthetic steps: 1): by 3 - methyl thiophene as raw materials, adding N - bromosuccinimide synthesis of 2 - bromo - 3 methyl thiophene; 2): by the 2 - bromo - 3 methyl thiophene to carbon tetrachloride as solvent, azobisisobutyronitrile as initiator with the N - bromosuccinimide synthesis of 2 - bromo - 3 - (bromomethyl) thiophene; 3): by the 2 - bromo - 3 - (bromomethyl) thiophene is 2 - iodo acyl benzoic acid oxidation to obtain 2 - bromo - 3 - thiophene formaldehyde; 4): by the 2 - bromo - 3 - thiophene formaldehyde sodium hydroxide aqueous solution as the solvent, is potassium permanganate oxidation to obtain 2 - bromo - 3 - thiophenecarboxylic acid. The invention has the advantages of: this invention uses the first to 2 of bit bromine substituted, then 3 of the oxidation of the synthetic route, mild reaction conditions, reactants are cheap and easily obtained, the yield is high. 2nd, greatly inhibit the double-bromo product, increasing the yield. (by machine translation)
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Paragraph 0025; 0026; 0027; 0028; 0029
(2017/08/28)
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- Synthetic Utility of Arylmethylsulfones: Annulative π-Extension of Aromatics and Hetero-aromatics Involving Pd(0)-Catalyzed Heck Coupling Reactions
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A straightforward and general method for the synthesis of annulated thiophene, dibenzothiophene, and carbazoles analogues has been achieved involving alkylation of 2-bromo-1-(phenylsulfonylmethyl)arene/heteroarene with arylmethyl bromides/heteroarylmethyl bromides using t-BuOK as a base in DMF, followed by Pd(0)-mediated intramolecular Heck coupling in the presence of K2CO3 in DMF at 80-140 °C. The attractive feature of this protocol is that a wide variety of π-conjugated heterocycles could be readily accessed by an appropriate choice of arylmethylsulfones and benzylic bromides.
- Sankar, Elumalai,Raju, Potharaju,Karunakaran, Jayachandran,Mohanakrishnan, Arasambattu K.
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p. 13583 - 13593
(2017/12/26)
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- Effect of conjugated side groups on the photovoltaic performances of triphenylamine-based dyes sensitized solar cells
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Three novel organic dyes (LD1, LD2 and LD3) with conjugated side groups on the thiophene π-bridge are designed and synthesized for dye sensitized solar cells (DSSCs). The photophysical, electrochemical, and photovoltaic properties of the dyes have been successfully tuned by incorporating different conjugated side groups into the thiophene π-bridges moieties of dyes. Compared with the analogous dyes with non-conjugated side groups, the side group-conjugated dyes exhibited wider absorption spectra, higher molar extinction coefficients, and better photovoltaic performances. For the LD2-based DSSCs, the maximum power conversion efficiency (PCE) of 7.71% is obtained under AM 1.5 G irradiation (100 mW cm-2). The result demonstrates that high-performance DSSCs can be acquired by choosing suitable conjugated side groups into the π-bridges moieties of organic dyes.
- Long, Jun,Liu, Xunshan,Guo, Huan,Zhao, Bin,Tan, Songting
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p. 222 - 231
(2015/10/19)
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- Conjugated Thiophene-Fused Isatin Dyes through Intramolecular Direct Arylation
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We report on the design, synthesis, and properties of innovative, planar, π-conjugated compounds in which a thiophene ring is fused with the skeleton of the naturally occurring dye isatin. The synthesis is achieved in high yields making use of an intramolecular direct arylation reaction as the key step, making the overall process potentially scalable. The synthetic sequence has been demonstrated also for an isatin bearing fluorine substituents on the aromatic ring. NMR and X-ray studies demonstrate the crosstalk occurring between the fused, coplanar, and conjugated moieties, making these novel dyes with a donor-acceptor character. Cyclic voltammetry and UV-vis studies confirm very interesting HOMO-LUMO levels and energy gaps for the new compounds.
- Nitti, Andrea,Signorile, Marco,Boiocchi, Massimo,Bianchi, Gabriele,Po, Riccardo,Pasini, Dario
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p. 11035 - 11042
(2016/11/29)
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- Synthesis and properties of regioregular poly(3-substituted thiophene) bearing disiloxane moiety in the substituent. remarkably high solubility in hexane
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Regioregular poly(3-substituted thiophene) derivative bearing pentamethyldisiloxane moiety at the 3-substituent is prepared by nickel-catalyzed polymerization reactions with dehydrobrominative or debrominative generation of the organometallic monomer. The monomer precursors 2-bromo-3-(4- pentamethyldisiloxybutan-1-yl)thiophene (1a) and 2,5-dibromo- 3-(4-pentamethyldisiloxybutan-1-yl)thiophene (1b) are prepared from 3-methylthiophene with 45 steps in overall good yields. Treatment of 1a with TMPMgCl￠LiCl at room temperature for 3 h forms an organometallic monomer and following the addition of a nickel catalyst affords the corresponding polythiophene bearing a disiloxane moiety in the side chain. The reaction of 1b with Grignard reagent leads to the similar monomer and addition of a catalytic amount of [NiCl2(dppe)] also affords polythiophene in highly regioregular manners. The obtained polythiophene is found to be dissolved in a hydrocarbon such as hexane.
- Mori, Atsunori,Ide, Kenji,Tamba, Shunsuke,Tsuji, Satoru,Toyomori, Yuka,Yasuda, Takeshi
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supporting information
p. 640 - 642
(2014/05/20)
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- π-complexation in nickel-catalyzed cross-coupling reactions
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The kinetic isotope effect (KIE) is used to experimentally elucidate the first irreversible step in oxidative addition reactions of a zerovalent nickel catalyst to a set of haloarene substrates. Halogenated o-methylbenzene, dimethoxybenzene, and thiophene derivatives undergo intramolecular oxidative addition through irreversible π-complexation. Density functional theory computations at the B3LYP-D3/TZ2P-LANL2TZ(f)-LANL08d level predict η2-bound π-complexes are generally stable relative to a solvated catalyst plus free substrate and that ring-walking of the Ni(0) catalyst and intramolecular oxidative addition are facile in these intermediates.
- Sontag, S. Kyle,Bilbrey, Jenna A.,Huddleston, N. Eric,Sheppard, Gareth R.,Allen, Wesley D.,Locklin, Jason
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p. 1836 - 1841
(2014/03/21)
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- Green halogenation of aromatic heterocycles using ammonium halide and hydrogen peroxide in acetic acid solvent
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The green generation of X+ (X = Br, I) using hydrogen peroxide in aqueous acetic acid allows access to aromatic heterocyclic halides in yields and purities comparable to syntheses employing N-bromosuccinimide. In activated and unsubstituted thiophene rings, regioselectivity is quantitative for positions α to the sulfur; pyrroles also give quantitative reactions, at least initially. Deactivated rings, including furans and thiazoles, as well as thiophenes with strongly electron-withdrawing groups showed little to no reactivity under the conditions investigated. The reaction shows remarkable functional group tolerance (to alcohol, nitro, alkyl, halo, and carbonyl groups), as shown through reaction with substituted phenols. In all bromination reactions, reaction yields and regiochemistry were very similar to reactions involving N-bromosuccinimide in tetrahydrofuran solvent.
- D'Aleo, Danielle N.,Allard, Sheena R.,Foglia, Cassandra C.,Parent, Shawna L.M.,Rohr, David J.,Gottardo, Christine,MacKinnon, Craig D.
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supporting information
p. 679 - 683
(2013/08/23)
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- PROCESS FOR PRODUCTION OF OXIDATION REACTION PRODUCT OF AROMATIC COMPOUND
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The present invention provides a process for producing an oxidation reaction product of an aromatic compound, having excellent environmental load reduction performance, cost reduction performance, etc. Provided is a process for producing an oxidation reaction product of a raw material aromatic compound by reacting the raw material aromatic compound with an oxidizing agent. The process further uses an electron donor-acceptor linked molecule. The process includes the step of: reacting the electron donor-acceptor linked molecule in an electron-transfer state, the oxidizing agent, and the raw material aromatic compound, thereby generating an oxidation reaction product resulting from oxidation of the raw material aromatic compound.
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(2012/07/14)
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- ANTIMICROBIAL/ADJUVANT COMPOUNDS AND METHODS
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Among other things, in general, antimicrobial and/or adjuvant compounds are provided according to Formula la: (Ia) in which E and R1-11 have the meanings described herein; and prodrugs and pharmaceutically acceptable salts thereof. Other formulae and methods of use are also provided.
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Page/Page column 66
(2012/09/21)
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- Azulene-containing organic chromophores with tunable near-IR absorption in the range of 0.6 to 1.7 μm
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Near-infrared (NIR) absorption in the range of 0.75-2.5 μm is in great demand for a variety of applications but currently the majority of commercial NIR devices are based on inorganic materials due to the limited number of organic materials that are active in this range. Here we present the preparation and optical studies of a new series of stable azulene-containing NIR chromophores whose absorption can be tuned in the range of 0.6-1.7 μm. DFT calculation revealed that the protonation-induced low excitation gap was attributable to the substantial intramolecular charge transfer. The Royal Society of Chemistry 2012.
- Wang, Fuke,Lin, Ting Ting,He, Chaobin,Chi, Hong,Tang, Tao,Lai, Yee-Hing
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scheme or table
p. 10448 - 10451
(2012/09/07)
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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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- MULTICYCLIC COMPOUNDS AND METHODS OF USE THEREOF
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Provided herein are multicyclic compounds, methods of their synthesis, pharmaceutical compositions comprising the compounds, and methods of their use. The compounds provided herein are useful for the treatment, prevention, and/or management of various neurological disorders, including but not limited to, psychosis and schizophrenia.
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Page/Page column 107
(2011/06/25)
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- End group-functionalization and synthesis of block-copolythiophenes by modified nickel initiators
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Polythiophenes with alcohol, tosylate, azide, ethynylene, carboxylic acid, and amine end groups were prepared by a combination of functionalized nickel initiators and postpolymerization reactions. The azide and ethynylene polymers were subsequently used in a click reaction to produce a conjugated block copolymer. Finally, a conjugated triblock-copolymer was synthesized by means of a chain growth polymerization initiated by a binuclear nickel initiator.
- Smeets, Alfons,Willot, Pieter,De Winter, Julien,Gerbaux, Pascal,Verbiest, Thierry,Koeckelberghs, Guy
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experimental part
p. 6017 - 6025
(2012/03/08)
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- Self-assembly behaviour of conjugated terthiophene surfactants in water
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Conjugated self-assembled systems in water are of great interest because of their potential application in biocompatible supramolecular electronics, but so far their supramolecular chemistry remains almost unexplored. Here we present amphiphilic terthiophenes as a general self-assembling platform for the construction of conjugated aggregates, providing access to aggregates with different morphologies without changing the basic molecular design. We explored the design parameters of these amphiphilic terthiophenes in detail, leading to the selection and synthesis of in total 8 new amphiphilic oligothiophenes. Their aggregation behaviour was investigated by absorbance and fluorescence spectroscopy, dynamic light scattering, and cryo-transmission electron microscopy. Critical micelle concentrations as low as 0.01 mM were found and different sized aggregates ranging from several nanometres up to 200 nm. The aggregate morphology could also be tuned by changing the substitution pattern of hydrophilic and hydrophobic moieties, leading to different types of aggregates ranging from globular- and elongated micelles to bilayers. Remarkably, aggregation had only little effect on the electronic and spectroscopic properties of the oligothiophenes, which will be of interest for their application in supramolecular electronics.
- Van Rijn, Patrick,Janeliunas, Dainius,Brizard, Aurelie M.,Stuart, Marc C. A.,Koper, Ger J. M.,Eelkema, Rienk,Van Esch, Jan H.
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scheme or table
p. 558 - 567
(2011/06/20)
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- Low-cost dyes based on methylthiophene for high-performance dye-sensitized solar cells
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Three donor-acceptor, π-conjugated (D-π-A) dyes containing methylthiophene or vinylene methylthiophene as π-conjugated spacer were utilised in dye-sensitized nanocrystalline TiO2 solar cells. The relationship between the structure of the dyes and their photophysical, electrochemical and photovoltaic properties was investigated systematically. The vinyl unit, introduced as the π-conjugated spacer, leads to unfavorable back-electron transfer and decrease of the open-circuit voltage. A dye-sensitized solar cell based on 2-cyano-3-(5-(4-(diphenylamino)phenyl)-4-methylthiophenyl-2-yl) acrylic acid displayed the most efficient solar-to-electricity conversion efficiency of the dyes with a maximum η value of 8.27% (Voc?=?0.72?V, Jsc?=?15.76?mA?cm-2, FF?=?0.73) under simulated AM 1.5 G solar irradiation (100?mW?cm-2).
- Tian, Zongfang,Huang, Meihua,Zhao, Bin,Huang, Hui,Feng, Xiaoming,Nie, Yujuan,Shen, Ping,Tan, Songting
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scheme or table
p. 181 - 187
(2010/07/15)
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- Conformation as a protecting group: A regioselective aromatic bromination en route to complex π-electron systems
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(Chemical Equation Presented) A new strategy to achieve regioselective functionalization of a sterically congested aromatic system driven by conformational demands is described. Electrophilic substitution occurs at the more planarizable subunit without undesired chemistry at mutually reactive sites and without the need for protecting or masking groups that must be manipulated later. Model studies are described to understand this selectivity, and possibilities for the construction of orthogonal, differentially substituted π-systems of relevance for molecular electronics are demonstrated.
- Guthrie, Daryl A.,Tovar, John D.
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supporting information; body text
p. 4323 - 4326
(2009/06/06)
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- Palladium-catalyzed C-H homocoupling of bromothiophene derivatives and synthetic application to well-defined oligothiophenes
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Synthesis of oligothiophenes of well-defined structures that possess 2-8 thiophene units is performed with a new synthetic strategy involving C-H homocoupling of bromothiophenes and cross-coupling with organostannanes. Tolerance of the carbon-bromine bond to the palladium-catalyzed C-H homocoupling results in oligothiophenes bearing C-Br bonds at the terminal thiophene rings, which allow further transformation by the catalysis of a transition-metal complex.
- Takahashi, Masabumi,Masui, Kentaro,Sekiguchi, Hiroki,Kobayashi, Nobuhiko,Mori, Atsunori,Funahashi, Masahiro,Tamaoki, Nobuyuki
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p. 10930 - 10933
(2007/10/03)
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- Acyl sulfonamide anti-proliferatives. Part 2: Activity of heterocyclic sulfonamide derivatives
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The anti-proliferative activity of acylated heterocyclic sulfonamides is described in Vascular Endothelial Growth Factor-dependent Human Umbilical Vascular Endothelial Cells (VEGF-HUVEC) and in HCT116 tumor cells in a soft agar diffusion assay.
- Mader, Mary M.,Shih, Chuan,Considine, Eileen,De Dios, Alfonso,Grossman, Cora Sue,Hipskind, Philip A.,Lin, Ho-Shen,Lobb, Karen L.,Lopez, Beatriz,Lopez, Jose E.,Cabrejas, Luisa M. Martin,Richett, Michael E.,White, Wesley T.,Cheung, Yiu-Yin,Huang, Zhongping,Reilly, John E.,Dinn, Sean R.
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p. 617 - 620
(2007/10/03)
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- Novel aminophenyl ketone derivatives
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Novel heteroaryl aminophenyl ketone derivatives which are inhibitors of MAP kinases, in particular the p38 MAP kinase, are useful as anti-inflammatory agents in the prophylaxis or treatment of inflammatory diseases or conditions.
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- New and efficient access to 3-substituted 2,5-dibromothiophenes. Consecutive nickel-catalyzed electrochemical conversion to thienylzinc species
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We have achieved the stepwise synthesis of 3-substituted thienylzinc reagents using both electrochemical methods and an original bromination procedure. For several compounds 3-bromothiophene was the starting substrate, which was functionalized according to recently developed electrochemical procedures. The nickel-catalyzed electrochemical reduction of the resulting 3-substituted 2,5-dibromothiophenes in the presence of zinc salts allowed the formation of monothienylzinc species in good yields. The selectivity of this reaction is discussed within the context of the electrochemical synthesis of regioregular polythiophenes.
- Mellah,Labbe,Nedelec,Perichon
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p. 318 - 321
(2007/10/03)
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- Study of an efficient and selective bromination reaction of substituted thiophenes
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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.
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p. 1607 - 1610
(2007/10/03)
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- Synthesis of substituted oligothiophenes and X-ray crystal structures of 3′-methyl-2,2′:5′,2″-terthiophene, 3,3″-dimethyl-2,2′:5′,2″-terthiophene and 5′-(2-thienyl)-2,2′:3′,2″-terthiophene
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A range of substituted oligothiophenes has been prepared and characterised. Crystal structures were determined for three substituted terthiophenes. Both in solution and in the solid state, syn-conformers were found to be populated to a greater extent than expected.
- Chaloner, Penny A.,Gunatunga, Sumudu R.,Hitchcock, Peter B.
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p. 1597 - 1604
(2007/10/03)
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- Convergent synthetic routes to orthogonally fused conjugated oligomers directed toward molecular scale electronic device applications
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This paper describes the synthetic organic phase of a project directed toward the construction of molecular scale electronic devices. Outlined is a convergent synthetic route to orthogonally fused conjugated organic oligomers. The final systems are to have a potentially conducting chain fused perpendicularly to a second potentially conducting chain via a a bonded network. One of the core segments synthesized is based on a spirobithiophene moiety with a central silicon atom. It is formed by a zirconium-promoted bis(bicyclization) of a tetrapropargylsilane. The second core is a 9,9′-spirobifluorene system. Terminal halide groups provide the linkage points for further extension of the chains via Pd-catalyzed or Pd/Cu-catalyzed cross coupling methods. All four branching arms are affixed to the core in a single operation, thus making the syntheses highly convergent. In the cases of the larger functionalized systems, alkyl substituents on the thiophenes afford soluble materials. In order to prepare the molecules with > 50 A lengths, an iterative divergent/convergent approach had to be utilized for the construction of oligo(thiophene-ethynylene) branching arms. Organopalladium-catalyzed procedures are used extensively for the syntheses of the orthogonally fused compounds.
- Wu, Ruilian,Schumm, Jeffry S.,Pearson, Darren L.,Tour, James M.
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p. 6906 - 6921
(2007/10/03)
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- NOVEL HALOGENATION OF THIOPHENES WITH BENZENESELENINYL CHLORIDE AND ALUMINUM HALIDE
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In the presence of aluminum halide, benzeneseleninyl chloride is an efficient regioselective halogenating reagent for heterocyclic compounds such as thiophene, 2-methylthiophene, 3-methylthiophene, 2,5-dimethylthiophene, and furan.In the case of pyrrole, no halogenated product was obtained.A plausible reaction mechanism involving a positive halogen intermediate is proposed.
- Kamigata, Nobumasa,Suzuki, Takashi,Yoshida, Masato
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- Selective oxabicycloalkanes
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A group of oxabicycloalkane herbicides of the formula, , JOCH2Q, , wherein J is a substituted oxabicycloalkane moiety; and, Q is optionally substituted phenyl or substituted thienyl;, exhibit selective herbicidal activity, especially in paddy rice. The compounds may be made e.g. by coupling an appropriately substituted thenyl bromide with the appropriate substituted oxabicycloalkanol.
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- 2-(2,2-dihaloethenyl)-5-arylthiophene pesticides
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Thiophene derivatives of the following formula are effective as acaricides: STR1 wherein RA is selected from -hydrogen, -halogen, -lower alkyl, hydroxy, -lower alkoxy, -lower alkylthio, -lower alkoxyalkoxy, -lower alkoxycarbonyl, -aryloxycarbonyl, -lower alkoxycarbonyloxy, -lower alkylsulfonyl, -lower alkylsulfonyloxy, -arylsulfonyloxy, and -lower alkyl phosphonyloxy; RB is -hydrogen, or RA and RB together are --C4 H4 --bridging 2'-3' or 3'-4'; R3 and R4 are selected from -hydrogen, -lower alkyl, and -aryl; X is -halogen; and Y is selected from -hydrogen and -halogen.
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- Charge Density - Activation Energy Correlations in Electrophilic Bromination of Thiophenes
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Charge density calculations are made on eleven thiophenes by Hueckel LCAO MO and Del Re methods and correlated with experimental activation energies(Ea) obtained for the molecular bromination of these compounds.The need for the inclusion of ?-charges in any correlation of charge density with kinetic data is stressed. - Keywords: Charge density/ Activation energy / Bromination of thiophenes
- Nanjan, M. J.,Kannappan, V.,Ganesan, R.
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- Kinetics of Bromination of Certain Substituted Thiophenes in Solution
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The general features of the kinetics of bromination of thiophene and substituted thiophenes have been investigated in dry and 15percent aq. acetic acid (v/v) and the Arrhenius activation energy (Ea) accurately determined for ten thiophene derivatives and interpreted.The mechanism proposed is supported with the detection of a ?-complex between bromine and 2-bromothiophene.
- Kannappan, V.,Nanjan, M. J.,Ganesan, R.
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p. 1183 - 1187
(2007/10/02)
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