- Hierarchical helical assembly of conjugated poly(3-hexylthiophene)-block- poly(3-triethylene glycol thiophene) diblock copolymers
-
We report on the solution-state assembly of all-conjugated polythiophene diblock copolymers containing nonpolar (hexyl) and polar (triethylene glycol) side chains. The polar substituents provide a large contrast in solubility, enabling formation of stably suspended crystalline fibrils even under very poor solvent conditions for the poly(3-hexylthiophene) block. For appropriate block ratios, complexation of the triethylene glycol side chains with added potassium ions drives the formation of helical nanowires that further bundle into superhelical structures.
- Lee, Eunji,Hammer, Brenton,Kim, Jung-Keun,Page, Zachariah,Emrick, Todd,Hayward, Ryan C.
-
-
Read Online
- Study of an efficient and selective bromination reaction of substituted thiophenes
-
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.
-
-
Read Online
- Synthesis and photovoltaic properties of polythiophene incorporating with 3,4-difluorothiophene units
-
Two polythiophene derivatives using fluorine atoms and hexyl or hexyloxy group as electron-withdrawing and donating substituents have been synthesized. The introduction of fluorine atoms to the polythiophene backbones simultaneously lowers the HOMO and narrows the bandgap, and the stronger electron-donating ability of hexyloxy side chain further reduces the bandgap. As a result, poly[3-hexylthiophene-2,5-diyl-alt-3,4-difluorothiophene] (PHTDFT) shows HOMO and bandgap of -5.31/1.83 eV and poly[3,4-dihexyloxythiophene-2,5-diyl-alt-3,4- difluorothiophene] (PDHOTDFT) shows HOMO and bandgap of -5.14/1.68 eV, both are lower than -4.76/2.02 eV of P3HT. Benefiting from the lower HOMO, PHTDFT:PC 61BM (1:1) polymer solar cells obtain a power conversion efficiency of 1.11% and an impressed open-circuit voltage of 0.79 V under solar illumination AM1.5 (100 mW/cm2). Two new polythiophene derivatives incorporating with 3,4-difluorothiphene units, PHTDFT and PDHOTDFT, show lower HOMO and narrower bandgap than that of P3HT. Benefiting from the lower HOMO, PHTDFT:PC61BM (1:1) polymer solar cells obtain a power conversion efficiency of 1.11% and an impressed open-circuit voltage of 0.79 V under solar illumination AM1.5 (100 mW/cm2). Copyright
- Huang, Linquan,Yang, Dong,Gao, Qiang,Liu, Yan,Lu, Shengmei,Zhang, Jian,Li, Can
-
-
Read Online
- Synthesis and Characterization of Diferrocenyl Conjugates: Varying π-Conjugated Bridging Ligands and its Consequence on Electrochemical Communication
-
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.
- Roy, Sourav Saha,Patra, Sanjib K.
-
-
Read Online
- Preparation of near-infrared absorbing composites comprised of conjugated macroligands on the surface of PbS nanoparticles
-
We report a facile macroligand strategy towards the synthesis of low-bandgap inorganic-organic composites comprised of semiconductor PbS nanoparticles and functional copolymers. For this, thiol-functional thiophene-based macroligands have been used as coligands for PbS nanoparticles. Thus, solution processable organic-inorganic hybrid materials with absorption in the near-infrared have been obtained. The resulting nanoparticle-polymer composites were characterized in detail by optical and FT-IR spectroscopy as well as TEM showing their potential as novel functional inorganic-organic hybrid materials when applied in initial proof-of-concept hybrid photovoltaic devices.
- Zhang, Jinming,Bahrig, Lydia,Puetz, Andreas,Kanelidis, Ioannis,Lenkeit, Daniel,Pelz, Simon,Hickey, Stephen G.,Klein, Michael F.G.,Colsmann, Alexander,Lemmer, Uli,Eychmüller, Alexander,Holder, Elisabeth
-
-
Read Online
- Synthesis, morphology, and field-effect transistor characteristics of new crystalline-crystalline diblock copolymers of poly(3-hexylthiophene-block-steryl acrylate)
-
We report the synthesis, morphology, and charge-transporting characteristics of new crystalline-crystalline diblock copolymers, poly(3-hexylthiophene-block-stearyl acrylate) (P3HT-b-PSA). Three different diblock copolymers, P1, P2, and P3, with P3HT/PSA polymerization degree block ratios of 60/26, 60/50, and 60/360, respectively, were prepared for investigating the morphology-property relationship and the dependence of optoelectronic properties on the block copolymer structure. Small- and wide-angle X-ray scattering indicated the presence of both P3HT and PSA crystalline domains and the presence of microphase separation among blocks. The transmission electron microscopy and atomic force microscopy results revealed that the diblock copolymers cast from chlorobenzene, tended to form needle-like morphologies. The field-effect mobilities of the diblock copolymers deposited on untreated SiO2 substrates, decreased with increasing PSA block length. In a sharp contrast, the mobilities enhanced with increasing PSA content when the P3HT-b-PSA was deposited on phenyltrichlorosilane (PTS)-treated substrates. The copolymers with a 60/360 P3HT/PSA ratio showed a good mobility of 4 × 10-3 cm2 V-1 s-1 and a high on/off ratio of 7 × 106 on PTS-treated substrates. This study highlighted the importance of the block ratio, the substrate and self-assembly structures on the charge transport characteristics of the crystalline-crystalline conjugated diblock copolymers.
- Lin, Jung-Chuan,Lee, Wen-Ya,Kuo, Chi-Ching,Li, Chaoxu,Mezzenga, Raffaele,Chen, Wen-Chang
-
-
Read Online
- Controlling phase separation and optical properties in conjugated polymers through selenophene-thiophene copolymerization
-
Selenophene-thiophene block copolymers were synthesized and studied. The properties of these novel block copolymers are distinct from those of statistical copolymers prepared from the same monomers with a similar composition. Specifically, the block copolymers exhibit broad and red-shifted absorbance features and phase-separated domains in the solid state. Scanning transmission electron microscopy and topographic elemental mapping confirmed that the domains are either rich in selenophene or thiophene, indicating that the blocks of distinct heterocycles preferentially associate with one another in the solid state. This preference is surprising in view of the chemical similarities between repeat units. The overall results demonstrate a phase separation that is controlled by elemental differences. As a result of this phase separation, these novel conjugated block copolymers should find utility in a variety of studies and optoelectronics uses.
- Hollinger, Jon,Jahnke, Ashlee A.,Coombs, Neil,Seferos, Dwight S.
-
-
Read Online
- Diruthenium(ii)-capped oligothienylethynyl bridged highly soluble organometallic wires exhibiting long-range electronic coupling
-
Organometallic molecular wires with π-conjugation along their molecular backbones are of considerable interest for application in molecular-scale electronics. In this regard, thienylethynyl-based π-conjugated oligomers of three, five and seven thienylethynyl units with -CC-H termini have been successfully synthesized through stepwise Pd(0)/Cu(i)-catalyzed Sonogashira coupling. The corresponding highly soluble diruthenium(ii) diacetylide complexes (O1-Ru2, O3-Ru2, O5-Ru2 and O7-Ru2, respectively) have been prepared by the reaction of cis-Ru(dppe)2Cl2 and NaPF6 in DCM with the corresponding rigid rod-like thienylethynyl oligomers with one, three, five and seven thienylethynyl π-conjugated segments containing alkynyl termini (O1, O3, O5 and O7). These Ru(ii)-Cl capped diacetylide complexes have been further functionalized by incorporating a phenylacetynyl moiety to afford [Ru(ii)-CC-Ph]-capped diacetylide organometallic wires (O1-Ru2-Ph, O3-Ru2-Ph, O5-Ru2-Ph and O7-Ru2-Ph). The photophysical properties of the highly soluble thienylethynyl-based oligomers and Ru(ii)-organometallic wires have been explored to understand their electronic properties. Electrochemical studies of the binuclear ruthenium(ii)-alkynyl complexes showed highly interesting results, revealing long-range electrochemical communication between the two remote Ru(ii) termini connected even with five and seven thienylethynyl units. DFT computational studies further support the long range electrochemical communication between the redox active metal termini through heavy participation of the thienylethynyl bridge in the corresponding mono-oxidized mixed valence species of the organometallic wire-like complexes.
- Saha Roy, Sourav,Sil, Amit,Giri, Dipanjan,Roy Chowdhury, Sabyasachi,Mishra, Sabyashachi,Patra, Sanjib K.
-
-
Read Online
- Copolymerization of Polythiophene and Sulfur to Improve the Electrochemical Performance in Lithium-Sulfur Batteries
-
We first report on the copolymerization of sulfur and allyl-terminated poly(3-hexylthiophene-2,5-diyl) (P3HT) derived by Grignard metathesis polymerization. This copolymerization is enabled by the conversion of sulfur radicals formed by thermolytic cleavage of S8 rings with allyl end-group. The formation of a C-S bond in the copolymer is characterized by a variety of methods, including NMR spectroscopy, size exclusion chromatography, and near-edge X-ray absorption fine spectroscopy. The S-P3HT copolymer is applied as an additive to sulfur as cathode material in lithium-sulfur batteries and compared to the use of a simple mixture of sulfur and P3HT, in which sulfur and P3HT were not covalently linked. While P3HT is incompatible with elementary sulfur, the new S-P3HT copolymer can be well dispersed in sulfur, at least on the sub-micrometer level. Sulfur batteries containing the S-P3HT copolymer exhibit an enhanced battery performance with respect to the cycling performance at 0.5C (799 mAh g-1 after 100 cycles for S-P3HT copolymer versus only 544 mAh g-1 for the simple mixture) and the C-rate performance. This is attributed to the attractive interaction between polysulfides and P3HT hindering the dissolution of polysulfides and the charge transfer (proven by electrochemical impedance spectroscopy) due to the homogeneous incorporation of P3HT into sulfur by covalently linking sulfur and P3HT.
- Oschmann, Bernd,Park, Jungjin,Kim, Chunjoong,Char, Kookheon,Sung, Yung-Eun,Zentel, Rudolf
-
-
Read Online
- An efficient and reliable procedure for the preparation of highly reactive Rieke zinc
-
Rieke zinc has a wide potential for applications in organic chemistry, notably for the synthesis of highly chemoselective organozinc reagents. However, due to the rather unreliable preparation method, leading to large batch to batch variations, its use has been rather limited. Rieke zinc is commonly prepared by the reduction of zinc chloride with lithium using a stoichiometric amount of naphthalene. In our hands, it was observed that the reaction outcome was highly dependent on the naphthalene source and purity grade. The presence of benzothiophene seems crucial to avoid coagulation of the zinc particles and the amount of benzothiophene has a large effect on the physical properties and the reactivity of the resulting zinc powder. Accordingly, highly reactive Rieke zinc was easily prepared from zinc chloride by adding an optimum amount (3 mol% with regard to ZnCl2) of benzothiophene into the lithium naphthalenide solution (prepared in situ). The Rieke zinc obtained in this way was successfully employed in the so-called "Rieke method" to prepare regioregular poly(3-hexylthiophene) (P3HT). The novel approach enables preparation of Rieke zinc in a reproducible manner, which considerably facilitates its use in both small molecule and polymer synthesis.
- Kudret, Suleyman,D'Haen, Jan,Lutsen, Laurence,Vanderzande, Dirk,Maes, Wouter
-
-
Read Online
- Cross-linked conjugated polymer fibrils: Robust nanowires from functional polythiophene diblock copolymers
-
A series of poly(3-hexyl thiophene) (P3HT)-based diblock copolymers were prepared and examined in solution for their assembly into fibrils, and post-assembly cross-linking into robust nanowire structures. P3HT-b-poly(3-methanol thiophene) (P3MT), and P3HT-b-poly(3-aminopropyloxymethyl thiophene) (P3AmT) diblock copolymers were synthesized using Grignard metathesis (GRIM) polymerization. Fibrils formed from solution assembly of these copolymers are thus decorated with hydroxyl and amine functionality, and cross-linking is achieved by reaction of diisocyanates with the hydroxyl and amine groups. A variety of cross-linked structures, characterized by transmission electron microscopy (TEM), were produced by this method, including dense fibrillar sheets, fibril bundles, or predominately individual fibrils, depending on the chosen reaction conditions. In solution, the cross-linked fibrils maintained their characteristic vibronic structure in solvents that would normally disrupt (dissolve) the structures.
- Hammer, Brenton A. G.,Bokel, Felicia A.,Hayward, Ryan C.,Emrick, Todd
-
-
Read Online
- Approaching the Integer-Charge Transfer Regime in Molecularly Doped Oligothiophenes by Efficient Decarboxylative Cross-Coupling
-
A library of symmetrical linear oligothiophene was prepared employing decarboxylative cross-coupling reaction as the key transformation. Thiophene potassium carboxylate salts were used as cross-coupling partners without the need of co-catalyst, base, or additives. This method demonstrates complete chemoselectivity and is a comprehensive greener approach compared to the existing methods. The modularity of this approach is demonstrated with the preparation of discreet oligothiophenes with up to 10 thiophene repeat units. Symmetrical oligothiophenes are prototypical organic semiconductors where their molecular electrical doping as a function of the chain length can be assessed spectroscopically. An oligothiophene critical length for integer charge transfer was observed to be 10 thiophene units, highlighting the potential use of discrete oligothiophenes as doped conduction or injection layers in organic electronics applications.
- Forgione, Pat,Hase, Hannes,Liu, Jiang Tian,Salzmann, Ingo,Taylor, Sarah
-
supporting information
p. 7146 - 7153
(2020/03/23)
-
- 1,2,3-Triazolyl functionalized thiophene, carbazole and fluorene based A-: Alt -B type π-conjugated copolymers for the sensitive and selective detection of aqueous and vapor phase nitroaromatics (NACs)
-
A series of highly emissive π-conjugated A-alt-B type copolymers (P1-P3) appended with a 1,2,3-triazole moiety was synthesized via Suzuki polymerization. The well-defined and soluble π-conjugated copolymers were characterized via multinuclear NMR spectroscopy and tetradetector GPC studies, showing a molecular weight (Mn) in the range of 16.4-20.1 kDa with a polydispersity index in the range of 1.25-1.42. The synthesized emissive π-conjugated polymer probes were explored as fluorescent chemosensors for nitroaromatic compounds (NACs) in solution, vapor and contact mode. Detailed photophysical and sensing studies were performed to understand the polymer-NAC interaction, inducing the selective fluorescence quenching of the π-conjugated polymer probes through the photoinduced electron transfer (PET) mechanism. All the polymeric probes (P1-P3) were highly reversible in nature with NACs, and thus could be reused multiple times. The limit of detection of the probes towards nitroaromatics was found to be in the range of 120-200 ppb with a high association constant in the order of 104 M-1. Furthermore, test paper kits were also fabricated, which allowed the trace detection of picric acid by the naked eye, making it a practical means for the quick, easy and inexpensive on-site detection of NAC-based explosives.
- Giri, Dipanjan,Patra, Sanjib K.
-
supporting information
p. 14469 - 14480
(2020/11/09)
-
- Synthesis and photovoltaic properties of low bandgap dimeric perylene diimide based non-fullerene acceptors
-
Non-fullerene organic acceptors have attracted increasing attention in recent years. One of the challenges in the synthesis of non-fullerene organic acceptors is to tune the absorption spectrum and molecular frontier orbitals, affording low bandgap molecules with improved absorption of the near-infrared solar photons. In this paper, we present the synthesis, optoelectronic and photovoltaic properties of a series of dimeric perylene diimide (PDI) based non-fullerene acceptors. These PDI dimers are bridged by oligothiophene (T) from 1T to 6T. With the increase of the oligothienyl size, the highest occupied molecular orbital (HOMO) energy is raised from -5.65 to -5.10 eV, while that of the lowest unoccupied molecular orbit (LUMO) is kept constant at -3.84 eV, affording narrow bandgap from 1.81 to 1.26 eV. The absorption from the oligothiophene occurs between 350 and 500 nm, which is complementary to that from its bridged PDI units, leading to a wide spectral coverage from 350 to 850 nm. The optimal dihedral angle between the bridged two perylene planes is dependent on the oligothienyl size, varying from 5° to 30°. The solubility of the dimers depends on the oligothienyl size and can be tuned by the alkyl chains on the bridged thienyl units. The possible applications as the solution-processable non-fullerene organic acceptor is primarily studied using commercial P3HT as the blend donor. The photovoltaic results indicate that 1T, 4T and 6T all yield a higher efficiency of ～1.2%, whereas 2T, 3T and 5T all give a lower efficiency of 0.5%. The difference in the cell performance is related with the tradeoff between the differences of absorption, HOMO level and film-morphology between these dimers.
- Zhang, Xin,Yao, Jiannian,Zhan, Chuanlang
-
p. 209 - 217
(2016/02/18)
-
- Synthesis and mesophase behavior of phenylthiophene based amphiphilic molecules
-
Novel amphiphilic molecules consisting of a rigid 2-phenylthiophene core, with a polar flexible tri(oxylethylene) moiety attached to the phenyl ring and one or two alkyl chains attached to the thiophene ring at the other side have been synthesized by using Ni(II) and Pd(0) catalyzed coupling reaction as key steps. The tri(oxylethylene) moieties were terminated with hydroxyl group, sodium carboxylate group and lithium carboxylate group respectively. The thermotropic and solvent induced liquid crystalline behavior of these substances was investigated by polarized optical microscopy, differential scanning calorimetry and X-ray diffraction. Thereby the influence of the terminal groups attached to the tri(oxylethylene) moities as well as the influence of the length and the number of the alkyl chains on the mesophase behavior were investigated. The single alkyl chain Na-carboxylate termianted derivatives show smectic A phases, double alkyl chain Na-carboxylate terminated derivatives show a thermo tropic hexagonal columnar mesophase, while columnar mesophases are found in both single and double alkyl chain Li-carbonate terminated derivatives. The model for molecular organization in the hexagonal columnar mesophase is established.
- Jing, Shan,Zhang, Ruilin,Dai, Heng,Du, Chao,Cheng, Xiaohong
-
scheme or table
p. 577 - 584
(2012/06/04)
-
- Grafting P3HT brushes on GO sheets: Distinctive properties of the GO/P3HT composites due to different grafting approaches
-
In this study, we have grafted poly(3-hexylthiophene) (P3HT) brushes on GO sheets via a silylation reaction of the surfaces of GO sheets and a succeeding "click" reaction (GO(C)/P3HT composite). Compared with pure P3HT and the blend of P3HT and GO, the GO(C)/P3HT composite shows a red-shifted optical absorption maximum because of increased conjugation length of the grafted P3HT, which might be due to the crowding of the P3HT chains grafted on GO sheets. For comparison, P3HT chains were also grafted on GO sheets via the amidation reaction of the carboxylic acid groups (GO(A)/P3HT composite). However, the GO(A)/P3HT composite doesn't show a red shift in the UV-visible spectrum. The overall fluorescence quenching in the GO(C)/P3HT composite includes both dynamic quenching and forming a non-fluorescent ground-state complex. Additionally, thermogravimetric analysis and X-ray photoelectron spectroscopy results demonstrate that the efficiency of grafting P3HT on GO sheets via the "click" reaction approach is higher than via the amidation reaction approach. Atomic force microscopy and transmission electron microscopy observations show that the GO(C)/P3HT composite sheets are much thicker than the GO(A)/P3HT composite sheets, due to the higher grafting efficiency of the "click" reaction approach. Therefore, this work opens a novel avenue to tuning the optical properties of conjugated polymers via surface grafting chemistry.
- Meng, Dongli,Sun, Jinhua,Jiang, Shidong,Zeng, Yi,Li, Yi,Yan, Shouke,Geng, Jianxin,Huang, Yong
-
supporting information
p. 21583 - 21591
(2013/01/15)
-
- Synthesis and photovoltaic properties of copolymers based on benzo[1,2-b:4,5-b′]dithiophene and thiophene with electron-withdrawing side chains
-
Six alternating conjugated copolymers (PL1-PL6) of benzo[1,2-b:4,5- b′]dithiophene (BDT) and thiophene, containing electron-withdrawing oxadiazole (OXD), ester, or alkyl as side chains, were synthesized by Stille coupling reaction. The structures of the polymers were confirmed, and their thermal, optical, electrochemical, and photovoltaic properties were investigated. The introduction of conjugated electron-withdrawing OXD or formate ester side chain benefits to decrease the bandgaps of the polymers and improve the photovoltaic performance due to the low steric hindrance of BDT. Bulk heterojunction polymer solar cells (PSCs) were fabricated based on the blend of the as-synthesized polymers and the fullerene derivative [6,6]-phenyl-C 61-butyric acid methyl ester (PC61BM) in a 1:2 weight ratio. The maximum power conversion efficiency of 2.06% was obtained for PL5-based PSC under the illumination of AM 1.5, 100 mW/cm2.
- Nie, Yujuan,Zhao, Bin,Tang, Peng,Jiang, Peng,Tian, Zongfang,Shen, Ping,Tan, Songting
-
experimental part
p. 3604 - 3614
(2012/05/05)
-
- POLYMERS COMPRISING 3 -SUBSTITUTED THIOPHENE MOIETIES AS ACTIVE LAYERS FOR SOLAR CELLS
-
The invention relates to new monomers and polymers as well as blends of such polymers with an electron acceptor. The invention also relates to a blend for use in a photovoltaic device, comprising: (a) a polymer comprising monomer units according to the formula (I), wherein L' is selected from the group consisting of L-C(O)O-J, L-C(O)NR'-J, L-OCO-J', L-NR'CO-J', L-SCO-J', L-O-J, L-S-J, L-Se-J, L-NR'-J and L-CN wherein L is a linear or branched alkylene group having from 1 to 10 carbon atoms, wherein J is a hydrogen atom or a linear or branched alkyl group having from 1 to 4 carbon atoms, wherein J' is a group having from 1 to 10 carbon atoms, being saturated or unsaturated, linear or branched, comprising a phenyl unit or not comprising a phenyl unit, wherein R' is a hydrogen atom or a linear or branched alkyl group having from 1 to 4 carbon atoms, and (b) an electron acceptor such as a fullerene derivative.
- -
-
Page/Page column 28-29
(2011/06/26)
-
- POLYMERISABLE COMPOUNDS FOR MAKING OPTO-ELECTRONIC DEVICES
-
This invention provides monomeric compounds represented by the structural formula (I) or the structural formula (II) which can be polymerized into crosslinkable polymers useful for producing opto-electronic devices.
- -
-
Page/Page column 25-26
(2010/04/03)
-
- Base-catalyzed halogen dance reaction and oxidative coupling sequence as a convenient method for the preparation of dihalo-bisheteroarenes
-
Figure presented A one-pot preparation of the 2,2′-dibromo-1, 1′-bisheteroarenes 3a-d from bromo-heteroarenes utilizing the sequence of the base-catalyzed halogen dance (BCHD) reaction and CuCl2-promoted oxidative coupling of the in situ formed α-lithio-β-halo-heteroarenes 2a-d provides a convenient access to precursors for the preparation of tricyclic heteroaromatic cores. The structures of 3a,b,d, 6, and 9 were confirmed by single-crystal X-ray analysis, and dibromides 3a and 3b were used for the preparation of dithieno-[2,3-b:3′,2′-d]-pyrrole 10a and its selenophene analogue 10b, respectively.
- Getmanenko, Yulia A.,Tongwa, Paul,Timofeeva, Tatiana V.,Marder, Seth R.
-
supporting information; experimental part
p. 2136 - 2139
(2010/08/05)
-
- Synthesis and photovoltaic properties of polythiophene stars with porphyrin core
-
Two novel porphyrin-polythiophene star-shaped polymer (P-bs1 and P-bs2) containing triphenylamine terminated poly(3′-hexyl-2,2′-bithiophene) and poly(3′-hexyl-2,2′-bithiophene) as four arms in the peripheral of porphyrin core were synthesized by Stille reaction. The thermal, photophysical, electrochemical and photovoltaic properties of the porphyrin-polythiophene derivatives were investigated. The porphyrin- polythiophene derivatives showed broad absorption in the region of 350 ～ 650 nm. In particular, the absorption intensity at 450 ～ 650 nm was greatly enhanced for the meso-substituted polythiophene derivatives, P-bs2. The photoluminescence spectra indicated that the emission peaks of porphyrin units were suppressed by the intensive emission of thiophene units. The electrochemical properties indicated that the porphyrin-polythiophene derivatives are potential electron-donor materials for bulk heterojunction solar cells and dye-sensitized solar cells (DSSCs). Polymer bulk heterojunction solar cells based on P-bs2:PCBM (1:1, w/w) showed power conversion efficiencies (PCE) up to 0.61% under the illumination of AM 1.5, 100 mW cm-2, which increased by 69% compared to that of P-bs1 (0.36%). Meanwhile, higher PCE of 2.17% and 3.91% based on P-bs1 and P-bs2 polymer-sensitized solar cells were attained. The better photovoltaic properties benefited from longer arms of polythiophene derivatives.
- Liu, Yijiang,Guo, Xia,Xiang, Na,Zhao, Bin,Huang, Hui,Li, Hui,Shen, Ping,Tan, Songting
-
scheme or table
p. 1140 - 1146
(2010/08/20)
-
- Synthesis and characterization of donor-acceptor poly(3-hexylthiophene) copolymers presenting 1,3,4-oxadiazole units and their application to photovoltaic cells
-
We have used Grignard metathesis polymerization to prepare poly(3-hexylthiophene)-based copolymers containing electron-withdrawing 4-tert-butyl phenyl-1,3,4-oxadiazole-phenyl moieties as side chains. We characterized these copolymers using 1H and 13C nuclear magnetic resonance spectroscopy, thermogravimetric analysis, and gel permeation chromatography. The band gap energy of copolymer was determined from the onset of the optical absorption. The quenching effects were observed in the photoluminescence spectra of the copolymers incorporating pendant electron-deficient 1,3,4-oxadiazole moieties on the side chains. The photocurrents of devices were enhanced in the presence of an optimal amount of the 1,3,4-oxadiazole moieties, thereby leading to improved power conversion efficiencies.
- Wang, Hsu-Shen,Su, Ming-Shin,Wei, Kung-Hwa
-
scheme or table
p. 3331 - 3339
(2011/04/25)
-
- PROCESS FOR BROMINATING ALKYLTHIOPHENES
-
What is described is a process for brominating alkylthiophene, in which an alkylthiophene of the general formula (I) where R is a branched or unbranched alkyl radical having 1 to 12 carbon atoms is contacted with stoichiometric amounts of HBr and H2O2, optionally in the presence of a solvent.
- -
-
Page/Page column 1
(2009/10/21)
-
- Mechanistic studies on Ni(dppe)Cl2-catalyzed chain-growth polymerizations: Evidence for rate-determining reductive elimination
-
The mechanisms for Ni(dppe)Cl2-catalyzed chain-growth polymerization of 4-bromo-2,5-bis-(hexyloxy)phenylmagnesium chloride and 5-bromo-4-hexylthiophen-2-ylmagnesium chloride were investigated. Rate studies utilizing IR spectroscopy and gas chromatography revealed that both polymerizations exhibit a first-order dependence on the catalyst concentration but a zeroth-order dependence on the monomer concentration. 31P NMR spectroscopic studies of the reactive organometallic intermediates suggest that the resting states are unsymmetrical NiII-biaryl and Ni II-bithiophene complexes. In combination, the data implicate reductive elimination as the rate-determining step for both monomers. Additionally, LiCl was found to have no effect on the rate-determining step or molecular weight distribution in the arene polymerization.
- Lanni, Erica L.,McNeil, Anne J.
-
supporting information; experimental part
p. 16573 - 16579
(2010/02/16)
-
- Thiophene-linked porphyrin derivatives for dye-sensitized solar cells
-
Three novel organic dyes based on porphyrin derivatives were designed and synthesized for dye-sensitized solar cells, resulting in a maximum power conversion efficiency (η) of 5.14% and a maximum IPCE value of 72% for a cell based on the PZn-hT dye. The Royal Society of Chemistry 2009.
- Liu, Yijiang,Xiang, Na,Feng, Xiaoming,Shen, Ping,Zhou, Weiping,Weng, Chao,Zhao, Bin,Tan, Songting
-
supporting information; experimental part
p. 2499 - 2501
(2009/09/30)
-
- Preparation and characterization of π-stacking quinodimethane oligothiophenes. Predicting semiconductor behavior and bandwidths from crystal structures and molecular orbital calculations
-
A series of new quinodimethane-substituted terthiophene and quaterthiophene oligomers has been investigated for comparison with a previously studied quinoid oligothiophene that has demonstrated high mobilities and ambipolar transport behavior in thin-film transistor devices. Each new quinoidal thiophene derivative shows a reversible one-electron oxidation between 0.85 and 1.32 V, a quasi-reversible one-electron second oxidation between 1.37 and 1.96 V, and a reversible two-electron reduction between -0.05 and -0.23 V. The solution UV-vis-NIR spectrum of each compound is dominated by an intense (ε ? 100 000 M-1 cm-1) low energy π-π* transition that has a γmax ranging between 648 and 790 nm. All X-ray crystal structures exhibit very planar quinoidal backbones and short intermolecular π-stacking distances (3.335-3.492 A). Structures exhibit a single π-stacking distance with parallel cofacial stacking (sulfur atoms of equivalent rings pointed in the same direction) or with alternating distances and antiparallel cofacial stacking (sulfur atoms of equivalent rings pointed in the opposite direction). Examples of the layered and herringbone-packing motifs are observed for both the parallel and the antiparallel cofacial stacking. Analysis of the X-ray structures and molecular orbital calculations indicates that all of these compounds have one-dimensional electronic band structures as a result of the π-stacking. For structures with a unique π-stacking distance, a simple geometric overlap parameter calculated from the shape of the molecule and the slip from perfect registry in the π-stack correlates well with the transfer integrals (f) calculated using molecular orbital theory. The calculated valence (633 meV) and conduction (834 meV) bandwidths for a quinoid quaterthiophene structure are similar to those calculated for the benchmark pentacene and indicate that both hole and electron mobilities could be significant.
- Janzen, Daron E.,Burand, Michael W.,Ewbank, Paul C.,Pappenfus, Ted M.,Higuchi, Hiroyuki,Da Silva Filho, Demetrio A.,Young, Victor G.,Bredas, Jean-Luc,Mann, Kent R.
-
p. 15295 - 15308
(2007/10/03)
-
- New and efficient access to 3-substituted 2,5-dibromothiophenes. Consecutive nickel-catalyzed electrochemical conversion to thienylzinc species
-
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
-
p. 318 - 321
(2007/10/03)
-
- 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
-
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.
-
p. 1597 - 1604
(2007/10/03)
-
- Synthesis and Properties of α,ω-Disubstituted Oligo(3-hexylthiophene)s and Oligothienoquinonoids in Head-to-head Orientation
-
The two types of Highly-ordered oligo(3-hexylthiophene)s in head-to-head orientation, a series od α,ω-disubstituted oligothiophenes and a series of bis(dicyanomethylene)oligothienoquinonoids, were synthesized.The properties of these compounds are discussed on the basis of the electronic spectra and cyclic voltammetry.
- Higuchi, Hiroyuki,Nakayama, Taketoshi,Koyama, Haruki,Ojima, Juro,Wada, Tatsuo,Sasabe, Hiroyuki
-
p. 2363 - 2378
(2007/10/03)
-
- Regiocontrolled synthesis of poly(3-alkylthiophenes) mediated by Rieke zinc: Their characterization and solid-state properties
-
A systematically regiocontrolled synthesis of poly(3-alkylthiophenes) (P3AT) mediated by Rieke zinc is reported. Rieke zinc undergoes oxidative addition to 2,5-dibromo-3-alkylthiophene or 2-bromo-5-iodo-3-alkylthiophene regioselectively to afford 2-bromo-5-(bromozincio)-3-alkylthiophene (2) or 2-bromo-5-(iodozincio)-3-alkylthiophene (10). The intermediate 2 or 10 can be polymerized catalytically to a series of regiospecific poly(3-alkylthiophenes) using different catalysts. The regioregularity of the polymer chain is solely controlled by the structure of the catalyst. An almost completely regioregular head-to-tail (HT) P3AT (4) is obtained by using Ni(DPPE)Cl2 ([1,2-bis-(diphenylphosphino)ethane]nickel(II) chloride). Use of Pd(DPPE)Cl2 leads to a reduction in the regioregularity (70: 30 HT/HH), while using Ni(PPh3)4 also leads to a much reduced regioregular P3AT (63:35 HT/HH). A totally regiorandom (50:50 HT/HH) P3AT (5) is afforded by using Pd(PPh3)4. The poly(3-butylthiophene) 4a is a 97% HT regioregular polymer. Other poly(3-alkylthiophenes) (alkyl = hexyl (4b), octyl (4c), decyl (4d), dodecyl (4e), and tetradecyl (4f)) are regioregular P3ATs with the HT linkage larger than 98.5% based on NMR analysis. Electronic absorption, X-ray diffraction, and crossed polarizing micrograph studies show that the cast films of the regioregular P3ATs (4) are self-organized, crystalline, flexible, and bronze-colored films with a metallic luster, while that of the regiorandom P3ATs (5) are amorphous and orange-colored films. The regioregular P3ATs exhibit a small bandgap (1.7 eV) which is 0.4 eV lower than that of regiorandom P3ATs (2.1 eV). Regioregular HT P3ATs have considerably improved electroconductivity and other physical properties over regiorandom P3ATs.
- Chen, Tian-An,Wu, Xiaoming,Rieke, Reuben D.
-
p. 233 - 244
(2007/10/02)
-
