125607-30-9Relevant articles and documents
Alternating copolymers based on 2,1,3-benzothiadiazole and hexylthiophene: Positioning effect of hexyl chains on the photophysical and electrochemical properties
El-Shehawy, Ashraf A.,Abdo, Nabiha I.,El-Barbary, Ahmed A.,Lee, Jae-Suk
, p. 4841 - 4852 (2011)
A series of donor-acceptor alternating π-conjugated copolymers based on 2,1,3-benzothiadiazole and hexylthiophene units has been synthesized by the palladium-catalyzed Stille cross-coupling method. Various precursory monomers possessing dibromo and bis(tributylstannyl) functionalities were readily prepared in high yields. Microwave-assisted polymerization proved efficient for the production of high-molecular-weight copolymers, ranging from 13550 to 52490 g mol-1. All copolymers exhibited excellent solubilities in most common organic solvents. The thermal properties of these copolymers were investigated by thermogravimetric analysis and differential scanning calorimetry, and the polymers showed high thermal stabilities. Incorporation of the benzothiadiazole unit into polyhexylthiophene chains affected the photophysical and electrochemical properties. The thin-film absorption spectra of all polymers are significantly red-shifted relative to the corresponding absorption bands in solution and exhibit broader absorption bands. The optical band gaps were estimated to be in the range of 2.02-1.74 eV. The highest occupied and lowest unoccupied molecular orbital energy levels are in the ranges of -5.37 to -5.66 eV and -3.33 to -3.44 eV, respectively. In the X-ray diffraction analysis of the deposited film of the copolymer P3, strong diffraction peaks were observed at 2θ = 5.72° (15.43 A) and 23.12° (3.84 A). These values relate to the distances between chains with interdigitated hexyl chains and to π-π stacking between the conjugated chains.
Precise control of quantum dot location within the P3HT-b-P2VP/QD nanowires formed by crystallization-driven 1D growth of hybrid dimeric seeds
Kim, Yong-Jae,Cho, Chul-Hee,Paek, Kwanyeol,Jo, Mijung,Park, Mi-Kyoung,Lee, Na-Eun,Kim, Youn-Joong,Kim, Bumjoon J.,Lee, Eunji
, p. 2767 - 2774 (2014)
Herein, we report a simple fabrication of hybrid nanowires (NWs) composed of a p-type conjugated polymer (CP) and n-type inorganic quantum dots (QDs) by exploiting the crystallization-driven solution assembly of poly(3- hexylthiophene)-b-poly(2-vinylpyridine) (P3HT-b-P2VP) rod-coil amphiphiles. The visualization of the crystallization-driven growth evolution of hybrid NWs through systematic transmission electron microscopy experiments showed that discrete dimeric CdSe QDs bridged by P3HT-b-P2VP polymers were generated during the initial state of crystallization. These, in turn, assemble into elongated fibrils, forming the coaxial P3HT-b-P2VP/QDs hybrid NWs. In particular, the location of the QD arrays within the single strand of P3HT-b-P2VP can be controlled precisely by manipulating the regioregularity (RR) values of P3HT block and the relative lengths of P2VP block. The degree of coaxiality of the QD arrays was shown to depend on the coplanarity of the thiophene rings of P3HT block, which can be controlled by the RR value of P3HT block. In addition, the location of QDs could be regulated at the specific-local site of P3HT-b-P2VP NW according to the surface characteristics of QDs. As an example, the comparison of two different QDs coated with hydrophobic alkyl-terminated and hydroxyl-terminated molecules, respectively, is used to elucidate the effect of the surface properties of QDs on their nanolocation in the NW.
Simple non-fullerene electron acceptors with unfused core for organic solar cells
Li, Yao,Xu, Yunhua,Yang, Fan,Jiang, Xudong,Li, Cheng,You, Shengyong,Li, Weiwei
, p. 222 - 224 (2019)
Two simple electron acceptors based on unfused bithiophene core and 1,1-dicyanomethylene-3-indanone end group were easily prepared via three synthetic steps. These acceptors exhibited broad absorption in the range of 300 nm to 800 nm, aligned energy levels and high crystallinity. When combined with a wide band gap donor polymer in non-fullerene solar cells, an initial power conversion efficiency of 2.4% was achieved. The relatively low efficiencies were due to the large phase separation in blended thin films, which is originated from their high aggregation tendency in thin films. Our results suggest that these electron acceptors with unfused core are promising candidates for commercial application of solar cells due to the low cost starting materials and facile synthesis.
Efficient deep-red electroluminescent donor-acceptor copolymers based on 6,7-dichloroquinoxaline
Gao, Xiang,Zhang, Yubao,Fang, Cheng,Cai, Xiang,Hu, Bin,Tu, Guoli
, p. 276 - 282 (2017)
Since the large steric hindrance caused by chlorine atoms not only suppresses the aggregation but also results in large stokes shift and low self-absorption, a series of donor-acceptor alternating copolymers based on 6,7-dichloroquinoxaline have been synthesized by modifying the structures of oligothiophenes. All the polymers have been well characterized to study the effects of the length of oligothiophenes and the steric hindrance on the optical, electronic and electroluminescent properties. It was observed that the intramolecular charge transfer absorption was weakened by steric hindrance. Unlike non-chloride analogues, prolonged conjugated length resulted in smaller bandgap, given similar steric hindrance. Deep-red emission centered at 678?nm with brightness about 1800?cd?m?2 was achieved with external quantum efficiency 1.34% using dopant/host technic.
The synthesis of head-to-tail (H-T) dimers of 3-substituted thiophenes by the hypervalent iodine(III)-induced oxidative biaryl coupling reaction
Dohi, Toshifumi,Morimoto, Koji,Kiyono, Yorito,Maruyama, Akinobu,Tohma, Hirofumi,Kita, Yasuyuki
, p. 2930 - 2932 (2005)
The head-to-tail (H-T) dimers could be obtained selectively by the oxidative coupling reaction of 3-substituted thiophenes using a combination of hypervalent iodine(III) reagents and trimethylsilyl trifluoromethanesulfonate. The Roval Society of Chemistry 2005.
Simple Separation of an Isomeric Mixture of Dihexylbithiophenes with Head-to-head and Head-to-tail Orientations
Higuchi, Hiroyuki,Hayashi, Noriyuki,Koyama, Haruki,Ojima, Juro
, p. 1115 - 1116 (1995)
The isomeric mixture of 3,3'-dialkylbithiophenes with head-to-head (H-H) and head-to-tail (H-T) orientations was separated into each isomer by using preferential bromination of the H-T isomer.This separation method proved to be useful for simultaneous preparation of the pure H-H and H-T bithiophenes which are inaccessable by other methods.
Intramolecular Noncovalent Interaction-Enabled Dopant-Free Hole-Transporting Materials for High-Performance Inverted Perovskite Solar Cells
Cao, Yan,Chen, Zhicai,Gao, Peng,Guo, Xugang,Huang, Jun,Lai, Ziwei,Liao, Qiaogan,Su, Mengyao,Wang, Dong,Woo, Han Young,Wu, Ziang,Yang, Kun,Zhang, Zilong
supporting information, (2021/12/06)
Intramolecular noncovalent interactions (INIs) have served as a powerful strategy for accessing organic semiconductors with enhanced charge transport properties. Herein, we apply the INI strategy for developing dopant-free hole-transporting materials (HTMs) by constructing two small-molecular HTMs featuring an INI-integrated backbone for high-performance perovskite solar cells (PVSCs). Upon incorporating noncovalent S???O interaction into their simple-structured backbones, the resulting HTMs, BTORA and BTORCNA, showed self-planarized backbones, tuned energy levels, enhanced thermal properties, appropriate film morphology, and effective defect passivation. More importantly, the high film crystallinity enables the materials with substantial hole mobilities, thus rendering them as promising dopant-free HTMs. Consequently, the BTORCNA-based inverted PVSCs delivered a power conversion efficiency of 21.10 % with encouraging long-term device stability, outperforming the devices based on BTRA without S???O interaction (18.40 %). This work offers a practical approach to designing charge transporting layers with high intrinsic mobilities for high-performance PVSCs.
Synthesis and Characterization of Diferrocenyl Conjugates: Varying π-Conjugated Bridging Ligands and its Consequence on Electrochemical Communication
Roy, Sourav Saha,Patra, Sanjib K.
, p. 2193 - 2201 (2019/04/17)
Organometallic wire-like complexes with ferrocenyl termini, conjugated with one and two units of thienylethynyl (M1 and M2) and thienyl (M3 and M4) groups, have been synthesized with a general formula of [Fc-C≡C-(Th-C≡C)1-2-Fc] and [Fc-(Th)1-2-Fc] (Fc = ferrocenyl, Th = thienyl) respectively. The diferrocenyl organometallic complexes have been characterized by various spectroscopic tools such as multinuclear NMR, FTIR, elemental analysis, and mass spectrometry. The electrochemical properties of these compounds have been investigated by cyclic (CV) and differential pulse voltammetry (DPV). The single reversible oxidation wave in diferrocenyl complexes with thienylethynyl spacers (M1 and M2) indicates the absence of intramolecular electrochemical communication between the two ferrocenyl termini. Interestingly, the diferrocenyl complexes with one and two thienyl spacers (M3 and M4) show two successive reversible one-electron oxidation waves, indicating electronic coupling between the two ferrocenyl (Fc) termini. The potential difference (ΔE1/2) between the two redox centers is 160 mV and 130 mV, respectively, with the corresponding comproportionation constants (Kc) of 6.2 × 102 and 1.5 × 102. Upon mono-oxidation of M3 by [Cp2Fe][BF4], a broad and weak intervalence charge-transfer (IVCT) transition is observed in the NIR region of 1200–2200 nm.
Convenient synthesis of organic-electronics-oriented building blocks via on-water and under-air homocoupling of (hetero)aryl iodides
Chen, Yi-An,Liu, Ching-Yuan
, p. 74180 - 74188 (2015/09/21)
We report herein an operationally simple homocoupling reaction that targets the convenient synthesis of organic-electronically important building blocks. A variety of synthetically useful bithiophene derivatives and functionalized biphenyls are efficiently prepared by an on-water and under-air protocol using Pd/C as catalyst. We find that Pd/C gives generally higher and cleaner homocoupling conversions than using Pd(OAc)2 in the cases of (hetero)aryl iodides since Pd(OAc)2 triggers more side reactions including dehalogenations and oligomerizations. Under the optimum conditions, a broad range of functional groups such as ester, ketone, aldehyde, nitrile, nitro, chloride, and bromide are well tolerated. We expect the present methodology would make a valuable synthetic contribution towards bridging green chemistry with thiophene-based organic materials.
Topological considerations for the design of molecular donors with multiple absorbing units
Lai, Lai Fan,Love, John A.,Sharenko, Alexander,Coughlin, Jessica E.,Gupta, Vinay,Tretiak, Sergei,Nguyen, Thuc-Quyen,Wong, Wai-Yeung,Bazan, Guillermo C.
supporting information, p. 5591 - 5594 (2014/05/06)
The molecule AT1, with two weakly conjugated chromophores, was designed, synthesized, and examined within the context of its film forming tendencies. While the addition of the second chromophore to the central core enables broadening of the absorption spectrum, this change is mostly apparent in films that are grown slowly. Grazing incidence X-ray scattering (GIWAXS) analysis indicates that these spectral characteristics correspond to an increase in solid state ordering. This information, in combination with differential scanning calorimetry, suggests that the overall molecular shape provides a kinetic barrier to crystallization. As a result, one finds the absence of molecular order when AT1 is combined with PC71BM in solution-cast blends. These findings highlight the importance of molecular topology when designing molecular components for solar cell devices.
