首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Lukovskaya  E. V.  Bobyleva  A. A.  Fedorova  O. A.  Fedorov  Yu. V.  Anisimov  A. V.  Didane  Y.  Brisset  H.  Fages  F. 《Russian Chemical Bulletin》2009,58(7):1509-1515
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.  相似文献   

2.
聚噻吩制备条件对其结构和导电性能的影响   总被引:1,自引:0,他引:1  
通过改变聚噻吩合成条件(温度、浓度、反应时间)得到各种不同样品, 用FESEM, FTIR光谱, Raman光谱, XRD, UV-Vis光谱和TG等手段对样品进行研究. 结果表明, 不同的制备条件会影响噻吩环的连接方式, 直接影响聚噻吩结构的分布. 导电性能研究表明, 聚噻吩的结构差异和其导电性能直接相关, 实验证明以α-α相连接的聚噻吩有更高的电导率.  相似文献   

3.
报道了3种取代聚噻吩,3-己基聚噻吩(P3HT)、3,4-二戊基聚噻吩(P34PT)、3-辛氧基聚噻吩(P3OOT)的合成方法1、H-NMR测试结果及UV-Vis吸收光谱和荧光光谱分析结果。用密度泛函方法计算了无取代噻吩、3-乙基噻吩、3,4-二乙基噻吩、3-乙氧基噻吩二聚体的电子性能。随聚合度的提高,聚合物能隙变窄。无取代噻吩二聚体的能隙为4.216 eV,重复单元长度为0.392 7 nm;乙基取代噻吩二聚体的能隙为4.733 eV,重复单元长度为0.393 9 nm;乙氧基取代噻吩二聚体的能隙为3.890 eV,重复单元长度为0.390 8 nm;双乙基取代噻吩二聚体的能隙为5.168 eV,重复单元长度为0.392 5 nm。理论变化规律与实验结果基本一致。  相似文献   

4.
The synthesis and characterization of a new family of soluble oligothiophene‐S,S‐dioxides and their use as building blocks to form polythiophene‐S,S‐dioxides via microwave‐assisted Stille coupling polymerization are described. Incorporation of the sulfone group into the polythiophene backbone leads to narrowing of the polymer bandgap, and while the energies of both Frontier orbitals in polythiophene‐S,S‐dioxide are lower with respect to polythiophenes, this tendency is considerably stronger for the lowest unoccupied molecular orbital than for the highest occupied molecular orbital, resulting in greater electron‐accepting ability. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011  相似文献   

5.
Two soluble side‐chain conjugated polythiophenes, poly{3‐[2‐(4‐octyloxy‐phenyl)‐vinyl]‐thiophene} (P3OPVT) and poly{3‐(4‐octyloxy‐phenylethynyl)‐thiophene} (P3OPET) have been synthesized successfully. In P3OPVT and P3OPET, substituted benzene rings are connected with the polythiophene backbone through trans carbon–carbon double bond and carbon–carbon triple bond, respectively. Absorption spectra of the P3OPVT and P3OPET both show two absorption peaks located in UV and visible region, respectively. The results of optical and electrochemical measurements indicate that the conjugated side‐chains can reduce the bandgap effectively. This type of side‐chain conjugated polythiophenes may be promising for the applications in polymer photovoltaic cells and field effect transistors. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2206–2214, 2006  相似文献   

6.
Bobacka J  Lewenstam A  Ivaska A 《Talanta》1993,40(9):1437-1444
The potentiometric response of some polythiophenes in aqueous solutions has been investigated. Polythiophene (PT), poly(2,2'-bithiophene) (PBT), poly(3-methylthiophene) (PMT), poly(3-octylthiophene) (POT) and poly(4,4'-dioctyl2,2'-bithiophene) (POTd) were electrochemically deposited on platinum in 0.1M LiBF(4)-propylene carbonate solution containing the corresponding monomer or dimer. Polymer electrodes were also prepared by solution casting of chemically synthesized poly(3-octylthiophene) (POTc) dissolved in chloroform. After film deposition (electrochemical or chemical) the polymer coated electrodes were used as indicator electrodes in potentiometric measurements. The open-circuit potential of the polymer electrodes was measured in aqueous solutions containing inorganic salts (10(-1)-10(-4)M). Interestingly, all the polythiophenes studied were found to give a cationic response to monovalent cations such as H(+), Li(+), Na(+), K(+) and NH(+)(4) (Cl(-) salts). The slope, calculated from the linear part of the response curve, was found to depend on the polythiophene used but always remained lower than that predicted for a Nernstian response. The polythiophenes also showed some sensitivity to divalent cations such as Mg(2+) and Ca(2+) (Cl(-)-salts). POT was used as the polymer to study the influence of the polymerization conditions on the potentiometric response. By investigating different polymers from the polythiophene family it was possible to evaluate how the starting material (monomer or dimer) and the presence of alkyl side-chains influence the potentiometric response of the polymer membranes.  相似文献   

7.
The electric conductivity of π‐conjugated and radical‐bearing polymers, i.e., polythiophenes bearing pendant galvinoxyl and phenoxyl radical groups, was measured using a microcomb‐shaped electrode. The electric conductivity was found to be enhanced by the radical content in the polymer. The infrared (IR) and Raman spectroscopies suggested a structural change from an aromatic form to a quinoid one in the polythiophene backbone by the phenoxyl radical generation. The effect of the pendant galvinoxyl radical's unpaired electron on the electric conductivity of the polythiophene was discussed by comparing the conductivity of a radical‐bearing polystyrene and a polythiophene mixed with low‐molecular radical molecules. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

8.
Electrochemical polymerization of 3-fluoroalkoxy and 3-fluoroether thiophenes givespolymers with relatively high molecular weights and good processibility. Investigationof these polymers by means of GPC indicates that an increase in the number of fluorineatoms in the fluorinated group results in a decrease in degree of polymerization of thepolymers in the same polythiophene series. As shown by NMR and FTIR, the polyfluo-rinated group substituted polythiophenes have regular 2, 5-coupling in their main chains.The SEM micrographs of the polymer films exhibit that polymer (1)-poly [3-2, 2, 3, 3-tetrafluoro-propoxy) thiophene] possesses more regular structure than the other polymersdo. Substitution of polythiophenes by fluorinated groups leads to the polymers with highelectric, electrochemical and thermal stability.  相似文献   

9.
Novel crown-containing styryl dyes (CSD) based on 15-crown-5-substituted benzothiazole with various electron-donating groups in thepara-position of the benzene ring were synthesized. Spectral and photochemical properties ofcis- andtrans-isomers of CSD and their complexes with Mg2+ ions in solutions were studied. By analysis of spectral parameters and the magnitudes and directions of the shifts of absorption (fluorescence) maxima, the effects of substituents and complex formation on the photochromism of CSD were elucidated. Using quantum-chemical calculations, the possibility of controlling the degree of participation of either of the two chromophores in the long-wave electron transition by complex formation was analyzed. For Part 19, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 999–1006, May, 1997.  相似文献   

10.
Azobenzene‐functionalized polythiophene derivatives, Poly[4‐((4‐(phenyl)azo)phenoxy)alkyl‐3‐thienylacetate] (alkyl=hexyl and octyl) (P6 and P8) and the copolymers of 3‐hexylthiophene and 4‐((4‐(phenyl)azo)phenoxy)alkyl‐3‐thienylacetate (alkyl=hexyl and octyl) (P66 and P86) were synthesized. The composition, structure, and thermal property of these polythiophene derivatives were fully characterized by NMR, FTIR, GPC, MDSC, and XRD. The structural dependence of the photochromic features and thermochromic behaviors were also investigated by means of photoluminescence and UV‐Vis absorption spectroscopy. The results have shown that the azobenzene substitution renders the homopolymer (P6 and P8) some interesting optical properties that can be modulated by UV light irradiation. In these azobenzene‐modified polythiophenes, the intensity of photoluminescent emission associated with the conjugated polythiophene main chain was found to decrease significantly upon UV irradiation. The finding suggests that the photo‐induced trans–cis isomerization of the azobenzene pendant groups has significant effect on photoluminescent emission. However, the effect becomes less prominent for copolymer P66 and P86 due to the lower content of azobenzene chromophore in the side chain of the copolymers. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1421–1432, 2005  相似文献   

11.
A new kind of all-organic heterojunction consisting of polythiophene and its derivatives was prepared by the electrochemical method in the presence of boron trifluoride diethyl ether as supporting electrolyte on indium–tin oxide glass electrode. It was observed that sequential-different oxidation potential among layers of polythiophenes is a prerequisite for the heterojunction to show rectification effect. The carrier-flow of the three semiconductors for PBrT/PT/PMT heterojunction was discussed in detail. Its rectification ratio, barrier height, and ideality factor were 392 (±2 V), 0.89 eV, and 8.1, respectively. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 2905–2910, 1998  相似文献   

12.
UV-vis optical spectra of several polythiophene with number of dimers n=1, 5, 10, 15 for cis- and trans-forms were investigated. The study was done theoretically using semi-empirical AM1 (Austin Model 1) and PM3 (Parametric Method 3) methods with the appropriate molecular geometry optimization. The experimental UV-vis absorption spectra were used for verification of the both semi-empirical theoretical models. With the increasing number of dimers a red shift of the absorption edge was observed. Solvent does not play a crucial role on behavior of the absorption spectrum. A comparison of the both semi-empirical methods with the observed experimental absorption spectra is performed. Role of state dipole moments of the investigated polythiophenes in the behavior of the observed UV-vis spectra is discussed. Particular role of pi-conjugated bonds is demonstrated.  相似文献   

13.
We have investigated the experimental X-ray and far-infrared responses of three polythiophenes synthesized from a thiophene, alpha-bithiophene, and alpha-quaterthiophene monomer. The X-ray data show that the crystallinity of the different polythiophene samples depends on the synthesis conditions. An excellent correlation between the crystallinity of polythiophenes and their far-infrared signatures is demonstrated. In addition, the assignment of the far-infrared phonon modes in polythiophenes is given by using both an experimental filiation procedure and first-principles calculations. In particular, the ring libration inside the polymeric chain, directly involved in the electron-phonon coupling, is assigned.  相似文献   

14.
聚噻吩与取代聚噻吩的能带结构的计算   总被引:1,自引:0,他引:1  
聚噻吩与取代聚噻吩的能带结构的计算曹阳,陈良进(苏州大学化学系苏州215006)关键词取代,聚噻吩,能带结构,导电性在五元杂环的高聚物中,3-取代聚噻吩已引起了人们广泛的兴趣,已有人对其能带结构和导电性能[1-2]尤其是其温度与导电性能的关系[3-5...  相似文献   

15.
Donor‐ or acceptor‐substituted polythiophenes have many potential applications in optoelectronics. Fluorinated polythiophenes are particularly attractive because of the presence of fluorine, which can withdraw electrons and also improve polymer chemical stability. Because of the promising future of these polymers, there has been much interest in identifying favorable synthetic routes to new fluorinated monomers and polymers. In this study, the monomer had an electron‐withdrawing fluorinated ester and was derived from 3‐thiophene carboxylic acid and 2,2,3,3,4,4,4‐heptafluoro‐1‐butanol. The synthesis of an n‐type fluorinated and terminal‐functionalized polythiophene was accomplished with the Ullmann coupling reaction. A polymer soluble in tetrahydrofuran was obtained with a molecular weight of approximately 15,000 g/mol. In solution, it exhibited a band gap of 2.4 eV, and the photoluminescent excitation and emission maxima were 370 nm and 555 nm, respectively. All peaks were bathochromically shifted when they were measured in the solid state. The glass‐transition and decomposition (in air) temperatures were 129 and 493 °C, respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4280–4287, 2005  相似文献   

16.
严德官  王卫江  吴浩青  杜庆琪 《化学学报》2006,64(24):2431-2436
采用Gaussian软件和HF方法, 通过从头计算(ab initio)法选取4-31G基组计算锂离子嵌入聚噻吩过程中结构与结合能的变化关系. 发现噻吩聚合时主要生成三或四聚合物. 聚合物在Li原子(或Li离子)嵌入后, 聚噻吩间距离明显变小, 同时发生电荷转移, 形成稳定嵌合物; 并使噻吩环的C-α—C-β键级变小. 同时, 研究了锂离子(或原子)嵌入后体系的HOMO, LUMO能级. 聚噻吩在嵌入锂离子时LUMO轨道能级变为负值, 成为电池反应得电子的正极. 而金属Li2 释放Li后的Li的HOMO能级为+0.7427 eV, 则成为给电子的负极. 由此, 可以完成由锂/聚噻吩在高氯酸锂电解质中组成的放电过程, 并提出嵌合键级概念用来表征锂在聚噻吩间的结合程度.  相似文献   

17.
Methods for the selective synthesis of mono-(RPcLnOAc), di-(RPc2Ln), and triphthalocyanines (RPc3Ln2) of rare-earth metals (Ln = Lu, Er, Eu) from symmetrically substituted 2,3,9,10,16,17,23,24-octaalkylphthalocyanines RPcH2 (R = Et, Bu) were developed. The synthesized complexes were characterized by NMR spectroscopy, mass spectrometry, and electronic absorption spectra. The conditions for 1H NMR spectra recording were optimized. Regularities in changing the spectral properties of the synthesized compounds, depending on the lanthanide nature and the planarity of metal phthalocyanine complexes, were found. tom@org.chem.msu.su Dedicated to Academician A. L. Buchachenko on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2024–2030, September, 2005.  相似文献   

18.
可溶性聚噻吩和富勒烯(主要是C60)及其衍生物,是聚合物太阳能电池中被广泛使用的给体和受体材料,它们之间的相容性和富勒烯的聚集效应对于太阳能电池能量转换效率有很大影响。将富勒烯与聚噻吩通过共价键连接在一起,可解决它们的共混膜中的相分离问题,有望提高器件效率,是未来有机和聚合物光伏材料研究的一个重要方向。本文按主链是聚噻吩或齐聚噻吩将这种连有富勒烯的材料分为两类,介绍了这些材料的合成方法、电化学性质及基于这些材料的太阳能电池器件近几年来的研究进展。  相似文献   

19.
This article reports the synthesis and characterization of a new polythiophene derivative phenoxy‐substituted, the poly[3‐(4‐octylphenoxy)thiophene] (POPOT). The oxidative polymerization was found to yield low molecular weight material, whereas a modified Grignard metathesis (GRIM) yielded polymers of high molecular weights. One‐ and two‐dimensional NMR indicated the latter to be highly regioregular. POPOTs exhibited higher thermal stabilities than equivalent alkoxy‐substituted polythiophenes and exhibited red shifts in the absorption spectra with respect to equivalent. The absorption spectra showed a red shifted λmax at 540 nm in tetrahydrofuran solutions and 580 nm in spin‐coated films, with respect to poly(3‐alkylthiophene)s. A further red shift of 40 nm in going from solution (540 nm) to solid states (580 nm) is correlated with results from density functional theory electronic structure calculations. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7505–7516, 2008  相似文献   

20.
Three new side‐chain conjugated polythiophene derivatives, poly{3‐[2‐(3‐methoxy‐4‐octyloxy‐phenyl)‐vinyl]‐thiophene} (P3MOPVT), poly{3‐[2‐(3,5‐dimethoxy‐4‐octyloxy‐phenyl)‐vinyl]‐thiophene} (P3DMOPVT), and poly{3‐[2‐(3,4‐dioctyloxy‐phenyl)‐vinyl]‐thiophene} (P3DOPVT), were synthesized by Wittig‐Hornor reaction and GRIM method and compared with poly{3‐[2‐(4‐octyloxy‐phenyl)‐vinyl]‐thiophene} (P3OPVT) for investigating the effect of the end groups of the conjugated side‐chain on the properties of the polymers. Owing to the electron‐donating ability of methoxy groups, the visible absorption peaks of P3MOPVT and P3DMOPVT solutions and films become stronger and red‐shifted compared with P3OPVT. The electrochemical bandgaps of the four polymers are 2.15 eV for P3OPVT, 1.99 eV for P3MOPVT, 1.85 eV for P3DMOPVT, and 2.36 eV for P3DOPVT, respectively, which indicate that the electron‐donating ability of the methoxy end group on the conjugated side chain of P3MOPVT and P3DMOPVT and the large steric hindrance of the two octyloxy end groups on the conjugated side chain of P3DOPVT have obvious influence on the electrochemical properties of the side‐chain conjugated polythiophenes. Polymer solar cells were fabricated with a structure of ITO/PEDOT:PSS/Polymer:PCBM/LiF/Al. The best device, based on P3DMOPVT, shows a power conversion efficiency of 1.63% under the illumination of AM1.5, 80 mW/cm2. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4916–4922, 2006  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号