Soluble Polythiophene Derivatives Research Articles

Synthesis, Characterization and Cell Imaging of Water Soluble Polythiophene Derivative†

Synthesis, Characterization and Cell Imaging of Water Soluble Polythiophene Derivative†

「光エネルギー変換人工膜」としての次世代有機系太陽電池

Next-generation solar cells based on new concepts and/or novel materials are currently attracting wide interests. The solar cell is recognized as “Artificial Membrane for Photo-energy Conversion”. Among new types of solar cells, dye-sensitized solar cell (DSSC) have received much attention as the low-cost solar cell. In our study, panchromatic photoelectric conversion up to around 1000 nm has been accomplished by the use of new sensitizer. We prepared the mechanical stack tandem solar cell showing a high overall power conversion efficiency (η) of about 12%. On the other hand, polymer-sensitized solar cell (PSSC) were constructed as hybrid organic solar cell by the use of novel soluble polythiophene derivatives with hydrophilic anchoring units. The PSSC sensitized with two types of the polymers yielded higher IPCE values in the visible region because of dual-sensitization. As for the other hybrid organic photovoltaics, surface complexes formed of TiO2 with dicyanomethylene compounds (TCNX) were used for the solar cells where the charge separation occurs directly by the charge-transfer transitions. At the last part, a three-electrode solar rechargeable battery, namely “energy-storable dye-sensitized solar cell (ES-DSSC)” was described.

Direct Electrosynthesis and Characterization of a New Soluble Polythiophene Derivative Containing Carboxyl Groups in Boron Trifluoride Diethyl Etherate

High-quality poly(3-thiophenemalonic acid) (P3TMA), a water-soluble polythiophene derivative, was successfully electrosynthesized in boron trifluoride diethyl etherate + 50% (by volume) trifluoroacetic acid at lower potential (0.1 V versus Pt). The carboxyl groups make P3TMA highly soluble in water, facilitating its potential application as a blue-light-emitting material. P3TMA film with conductivity of 16 S cm−1 obtained from this medium showed better redox activity and thermal stability. The structure and morphology of the polymer were studied by ultraviolet–visible, Fourier-transform infrared, and nuclear magnetic resonance spectroscopy and scanning electron microscopy, respectively. To the best of our knowledge, this is the first report on electrosynthesis of P3TMA film.

A novel polythiophene derivative as a sensitive colorimetric and fluorescent sensor for anionic surfactants in water

A novel cationic polythiophene derivative, poly[N,N,N-trimethyl-4-(thiophen-3-ylmethylene)cyclohexanaminium chloride] (PTCA-Cl), has been prepared successfully and applied as a colorimetric and fluorometric probe for the detection of anionic surfactants. In particular, a new method for the polymerization of cationic polythiophene derivatives is found, which has not been reported previously. The colorimetric and fluorescent response of PTCA-Cl to anionic surfactants have been investigated by absorption and emission spectroscopy. The sensing interaction can be apparently observed by the naked eye, which presents a great advantage for its practical applications. Moreover, the sensor (PTCA-Cl) shows high selectivity towards anionic surfactants in the presence of other negatively charged analytes, as well as high sensitivity with a detection limit at 10−9 M by using fluorimetry, which is the lowest ever achieved among all synthetic anionic surfactants sensors available. Therefore, the water soluble polythiophene derivative can be applied as a colorimetric and fluorescent probe for the detection of anionic surfactants with high selectivity and sensitivity.

Layer-by-layer deposition of a polythiophene/Au nanoparticles multilayer with effective electrochemical properties

Multilayers consisting of a water soluble polythiophene derivative and Au nanoparticles have been deposited onto different electrode substrates by means of layer-by-layer deposition technique. The assembly of the films has been performed by taking advantage of the electrostatic interactions between the positively charged imidazolic moiety of the polythiophene chain and the negative charges of citrate ions surrounding Au nanoparticles, as well of the affinity of S to Au. The nanoparticles result stably grafted to the organic matrix. The resulting modified electrodes have been characterised through electrochemical, spectroelectrochemical and microscopic techniques. The results evidenced that a high number of individual nanoparticles is present inside the multilayer. The presence of nanoparticles is of chief importance for most effective charge percolation through the multilayer, as suggested by the responses to electroactive probe species in solution. The electrocatalytic performances of the modified electrodes have been tested with respect to the oxidation of ascorbic acid.

Synthesis, characterization and electrochemical properties of new functional polythiophenes

Novel fully soluble polythiophene derivatives containing halogen or ester moieties at the end of a tetramethylenic side chain were synthesized using either the direct oxidative polymerization procedure of functionalized thiophene or the post polymerization functionalization of the preformed polymeric precursor. The structures of the polymers were characterized and their physical properties carefully investigated. High average molecular weights ( M ¯ n up to 30,550 g/mol) and thermostable products were obtained. The absorption wavelength of the polymers in different solvents can be tuned up by varying the composition of solvent mixtures. Cyclic voltammetry measurements displayed good charge transport properties, strongly related to the kind of substituent linked to the side chain.

Polymer-sensitized Solar Cells with Novel Soluble Polythiophene Derivatives

Polymer-sensitized Solar Cells with Novel Soluble Polythiophene Derivatives

Synthesis and properties of polythiophene derivatives containing triphenylamine moiety and their photovoltaic applications

AbstractA series of novel soluble polythiophene derivatives containing triphenylamine moiety were synthesized by Grignard metathesis (GRIM) method. The structures of the polymers were characterized and their physical properties were investigated. High molecular weight (Mn up to 25,800 g/mol) and thermostable polymers were obtained. The absorption spectra demonstrated that the absorption wavelength of the polymers could be tuned dramatically by introducing thiophene units in the main chain of the polymers. Photoluminescence spectra indicated that there was intramolecular energy transfer from the side chain to the main chain, and the maximum emission was red‐shifted gradually with the increase of thiophene units in the main chain. Cyclic voltammetry displayed that the polymers possessed relatively high oxidation potential, which promised good air stability and high open circuit voltage for photovoltaic cells application. Finally, bulk heterojunction photovoltaic devices were fabricated by using the polymers as donors and (6,6)‐phenyl C61‐butyric acid methyl ester (PCBM) as acceptor. The maximal open circuit voltage of the photovoltaic cells reached 0.71–0.87 V and the power conversion efficiencies of the devices were measured between 0.014% and 0.45% under white light at 100 mW/cm2. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3970–3984, 2008

Layer-by-layer deposited multilayer films of water soluble polythiophene derivative and goldnanoparticles exhibiting photoresponsive properties

Multilayer films of poly(3,4-(3′,3′-dithienyloxy) propyltrimethylammonium bromide) (P34TOPA) and 11-mercaptoundecanonate(MUA) capped gold nanoparticles (GNPs) have been fabricated by layer-by-layer (LBL)deposition. These films exhibit enhanced photoresponsive properties in comparison withthose of a monolayer of P34TOPA and MUA capped GNPs. The photocurrentdensities increased linearly with the bilayer number (1–10) of the multilayer films,indicating a sufficient charge separation and transportation. The size effect of goldnanoparticles on the photoresponsive properties of the multilayer films is also discussed.

A soluble and multichromic conducting polythiophene derivative

A new soluble polythiophene derivative was synthesized by both chemical and electrochemical oxidative polymerization of 1-4-nitrophenyl-2,5-di(2-thienyl)-1 H-pyrrole (SNSNO 2). Chemical method produces a polymer which is completely soluble in organic solvents. The structures of both the monomer and the soluble polymer were elucidated by 1H and 13C-NMR and FTIR. The average molecular weight has been determined by GPC to be Mn = 6.3 × 10 3 for the chemically synthesized polymer. P(SNSNO 2) was also synthesized via potentiostatic electrochemical polymerization. Characterizations of the resulting polymer were performed by cyclic voltammetry CV, FTIR and UV–Vis spectroscopy. Four-probe technique was used to measure the conductivities of the samples. Moreover, the spectroelectrochemical and electrochromic properties of the polymer film were investigated. In addition, dual type polymer electrochromic devices ECDs based on P(SNSNO 2) with poly3,4-ethylenedioxythiophene (PEDOT) were constructed. Spectroelectrochemistry, electrochromic switching and open circuit stability of the devices were studied. They were found to have good switching times, reasonable contrasts and optical memories.

Electrosynthesis of soluble polythiophene derivatives with high thermal stability

Poly(3-[4-(4-pentyl-cyclohexyl)-phenyl]-thiophene) (PPeChPhT) and poly(3-[2-fluoro-4-(4-pentyl-cyclohexyl)-phenyl]-thiophene) (PFPeChPhT) films were electrosynthesized by direct oxidation of the corresponding monomers in the mixed electrolytes of boron trifluoride diethyl etherate and ethyl ether (4:1, by volume). As grown PPeChPhT and PFPeChPhT films are in doped states and have conductivities of 0.10 and 0.11 S cm −1 , respectively. These two polymers in dedoped states are soluble in usual organic solvents such as tetrahydrofuran and chloroform, etc. The molar masses of the polymers were measured to be about 3400 g with dispersity of 1.32 (PPeChPhT) and 9300 g and dispersity of 1.51 (PFPeChPhT). Fluorescent spectral results showed that the polymers were strong yellow-green light emitters. Thermal degradation analysis results indicated that these polymers had high thermal stability with decomposition temperatures of about 500 °C.

Synthesis and Absorption Spectra of Poly(3-(phenylenevinyl)thiophene)s with Conjugated Side Chains

Six soluble polythiophene derivatives with phenylene−vinylene conjugated side chains were synthesized by GRIM or Stille methods. The absorption spectra of the polymers show two peaks located in the UV and visible region, where the visible absorption peak is attributed to the π−π* transition of the conjugated main chains and the UV absorption peak results from the conjugated side chains. By doubling the conjugation length of the phenylene−vinylene side chains and reducing the concentration of the conjugated side chains, we synthesized PT4, which possesses a strong and broad absorption in the visible region from 380 to 650 nm and is promising for the application in polymer solar cells. For the polymers of PEHPVT and PMEHPVT where every thiophene unit is attached with a conjugated side chain, the absorption spectra of their films red-shifted by 30 and 50 nm, respectively, in comparison with their solution. After thermal annealing at 130 °C for 10 min, the absorption of the films red-shifted further, and the ...

Synthesis and Characterization of Soluble Polythiophene Derivatives Containing Electron-Transporting Moiety

Soluble π-conjugated polythiophene derivatives containing the electron-transporting moiety were synthesized through FeCl3-oxidative polymerization; poly(3-(2-benzotriazoloethyl)thiophene) (PBET) and poly(3-(2-(5-chlorobenzotriazolo)ethyl)thiophene) (PCBET). The structure of the polymers was verified by FT-IR, 1H NMR, and element analysis. Introduction of the electron-transporting moiety, benzotriazole, on the side chain in poly(3-alkylthiophene) was an attempt to balance the injection rates of the electron and the hole from the opposite electrode into the light-emitting diodes (LEDs). This modification, therefore, would enhance electroluminescence (EL) efficiency. As the result, the external EL quantum efficiencies of PBET and PCBET were 7 and 3 times higher than that of poly(3-octylthiophene) (POT).

Soluble polythiophene derivatives for NO 2 sensing applications

Different soluble polythiophenes including poly(3-octylthiophene, poly(3-octylthiophene-co-thienylethanol) copolymers and c 14-alkylated poly(3,4-ethylenedioxythiophene methanol) were first synthesized and characterized by GPC, NMR, FT-IR and UV-visible spectroscopies. Films were deposited by spray coating on an especially designed interdigitated array of electrodes. Film responses during NO 2 pulses were monitored by conductivity measurements. The effects of chemical structure and storage conditions on gas sensitivity and reversibility are discussed.

Synthesis and Properties of a Soluble Polythiophene Derivative with a Urethane Side Chain

Abstract A solution processible thiophene polymer with a hydrogen-bond-forming urethane group in the side chain, viz., poly[2-(3-thienyl)ethanol n-butoxycarbonylmethylurethane] (PURET), has been synthesized. The polymer is soluble in a wide variety of solvents such as chloroform, dimethylsulfoxide, N-methylpyrrolidone, and trifluoroacetic acid among others. Optical quality thick films are obtained by solution casting. The presence of extensive hydrogen bonding is established with the help of temperature-dependent infrared spectroscopy. NMR spectroscopic study indicates the presence of about 33% regio-isomeric defects in the polymer. The polymer forms yellow-colored solutions (λmax = 430 nm) in most of the organic solvents, while in trifluoroacetic acid the polymer is oxidized and exhibits an additional band with an absorption maximum at around 780 nm. The conductivity of the polymer is in the order of 1 S/cm.

Studies on Conjugated Polymers: Preparation, Spectroscopic, and Charge-Transport Properties of a New Soluble Polythiophene Derivative: Poly(3',4'-dibutyl-2,2':5',2''-terthiophene)

Studies on Conjugated Polymers: Preparation, Spectroscopic, and Charge-Transport Properties of a New Soluble Polythiophene Derivative: Poly(3',4'-dibutyl-2,2':5',2''-terthiophene)

Picosecond photoinduced absorption and polarization memory in polythiophene derivatives

Although the fast dynamics of photoexcitations have been thoroughly explored in the conjugated polymer trans -polyacetylene, the experimental picture is much less complete for polymers in which the ground state is nondegerate. We report time-resolved photoinduced absorption data from films of one family of such polymers: the soluble polythiophene derivatives, poly(3-hexylthiophene) and poly(3-octylthiophene). Fast (<10 −12s bleaching of the interband transition is observed at 2.06 eV, accompanied by subgap photoinduced aborption at 1.17 eV. The results indicate a shift of a fraction of the oscillator strength, consistent with rapid structural relaxation to form polarons with associated gap states. By varying the polarization of the optical probe relative to that of the pump, photoinduced dichroism is observed. The magnitude of the initial dichroism implies that in spin-cast films the polymers are (locally) chain extended and chain aligned. The time decay of the polarization memory is consistent with rapid trapping of the initially mobile charged excitations.

Conducting polymer composites of soluble polythiophenes in polystyrene

We report optical and electronic properties of composites of soluble polythiophene derivatives and polystyrene over the full range of composition. The composite films were prepared by evaporating the solvent in an inert atmosphere from a solution containing both polymers. The films, made conducting by charge transfer doping (reaction with NOPF 6 in acetonitrile), display an insulator-metal transition at the percolation threshold: a volume fraction of ≈16% conducting polymer in polystyrene.