14282-76-9Relevant articles and documents
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
Chen, Liangjun,Liu, Wei,Yan, Yonggao,Su, Xianli,Xiao, Shengqiang,Lu, Xinhui,Uher, Ctirad,Tang, Xinfeng
, p. 2333 - 2344 (2019)
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).
Novel crown-containing 3-styryl derivatives of oligothiophenes: Synthesis, structure, and optical and electrochemical characteristics
Lukovskaya,Bobyleva,Fedorova,Fedorov,Anisimov,Didane,Brisset,Fages
, p. 1509 - 1515 (2009)
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.
Thallium(III) Trifluoroacetate-Trifluoroacetic Acid in the Chemistry of Polythiophenes. 2. Treatment of 3-Alkylthiophenes and Electron Paramagnetic Resonance Results
Tormo, Jordi,Jesus Moreno,Ruiz, Jordi,Fajari, Lluis,Julia, Luis
, p. 878 - 884 (1997)
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.
One-step synthesis of a thienylenepyridazinylenethienylene-based coil-rod-coil copolymer with enhanced emission and improved fluorescence stability
Wu, Wei,Xu, Haibo,Shen, Dezhi,Qiu, Tian,Fan, Li-Juan
, p. 1636 - 1644 (2013)
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
Bithiophene with winding vine-shaped molecular asymmetry. Preparation, structural characterization, and enantioselective synthesis
Toyomori, Yuka,Tsuji, Satoru,Mitsuda, Shinobu,Okayama, Yoichi,Ashida, Shiomi,Mori, Atsunori,Kobayashi, Toru,Miyazaki, Yuji,Yaita, Tsuyoshi,Arae, Sachie,Takahashi, Tamotsu,Ogasawara, Masamichi
, p. 1480 - 1486 (2016)
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.
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)
Yamamoto, Atsushi,Matsui, Yasunori,Ohta, Eisuke,Ogaki, Takuya,Sato, Hiroyasu,Furuyama, Taniyuki,Kobayashi, Nagao,Mizuno, Kazuhiko,Ikeda, Hiroshi
, p. 48 - 55 (2016)
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.
Influence of incorporating different electron-rich thiophene-based units on the photovoltaic properties of isoindigo-based conjugated polymers: An experimental and DFT study
Zhuang, Wenliu,Bolognesi, Margherita,Seri, Mirko,Henriksson, Patrik,Gedefaw, Desta,Kroon, Renee,Jarvid, Markus,Lundin, Angelica,Wang, Ergang,Muccini, Michele,Andersson, Mats R.
, p. 8488 - 8499 (2013)
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.
2-AMINO-N-(AMINO-OXO-ARYL-LAMBDA6-SULFANYLIDENE)ACETAMIDE COMPOUNDS AND THEIR THERAPEUTIC USE
-
Page/Page column 221, (2021/06/26)
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.
A study on regulating the conjugate position of NLO chromophores for reducing the dipole moment and enhancing the electro-optic activities of organic materials
Zhang, Hui,Tian, Yanxin,Bo, Shuhui,Xiao, Linghan,Ao, Yuhui,Zhang, Ji,Li, Ming
, p. 1380 - 1390 (2020/02/11)
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.
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
Zhang, Fengyu,Wang, Ran,Wang, Yajun,Zhang, Xiaomin,Liu, Bo
, p. 6256 - 6264 (2019/04/04)
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.
