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).
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.
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.
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.
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.
Nosyl (2-Nitrobenzenesulfonyl) Annulation Strategy toward Winding Vine-Shaped Bithiophenes
Ashida, Shiomi,Tanaka, Naoki,Ito, Yukiko,Matsuoka, Mitsuru,Hashimoto, Takayoshi,Okano, Kentaro,Miyazaki, Yuji,Kobayashi, Tohru,Yaita, Tsuyoshi,Mori, Atsunori
, p. 14797 - 14801 (2018/12/11)
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.
