The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Nobuhide Watanabe - One of the best experts on this subject based on the ideXlab platform.
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convenient method for the preparation of the 2 methyl thiophen 3 yl magnesium bromide lithium chloride complex and its application to the synthesis of 3 substituted 2 methylthiophenes
ChemInform, 2013Co-Authors: Masakazu Kogami, Nobuhide WatanabeAbstract:LiCl significantly accelerates the formation of Grignard reagent from inactive 3-bromo-2-methylthiophene (I) and thus provides access to a variety of 3-substituted 2-methylthiophenes (15 examples).
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convenient method for the preparation of the 2 methyl thiophen 3 yl magnesium bromide lithium chloride complex and its application to the synthesis of 3 substituted 2 methylthiophenes
Synthetic Communications, 2013Co-Authors: Masakazu Kogami, Nobuhide WatanabeAbstract:Abstract Lithium chloride was found to accelerate formation of the Grignard reagent from inactive 3-bromo-2-methylthiophene (1) and commercial magnesium metal. Based on this finding, a convenient and potentially scalable preparation of ethyl 2-methylthiophene-3-carboxylate (3) was achieved. In addition, this process has been found to provide a new, general approach to 3-substituted 2-methylthiophenes.
Masakazu Kogami - One of the best experts on this subject based on the ideXlab platform.
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convenient method for the preparation of the 2 methyl thiophen 3 yl magnesium bromide lithium chloride complex and its application to the synthesis of 3 substituted 2 methylthiophenes
ChemInform, 2013Co-Authors: Masakazu Kogami, Nobuhide WatanabeAbstract:LiCl significantly accelerates the formation of Grignard reagent from inactive 3-bromo-2-methylthiophene (I) and thus provides access to a variety of 3-substituted 2-methylthiophenes (15 examples).
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convenient method for the preparation of the 2 methyl thiophen 3 yl magnesium bromide lithium chloride complex and its application to the synthesis of 3 substituted 2 methylthiophenes
Synthetic Communications, 2013Co-Authors: Masakazu Kogami, Nobuhide WatanabeAbstract:Abstract Lithium chloride was found to accelerate formation of the Grignard reagent from inactive 3-bromo-2-methylthiophene (1) and commercial magnesium metal. Based on this finding, a convenient and potentially scalable preparation of ethyl 2-methylthiophene-3-carboxylate (3) was achieved. In addition, this process has been found to provide a new, general approach to 3-substituted 2-methylthiophenes.
Peter G. Pickup - One of the best experts on this subject based on the ideXlab platform.
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X-ray emission analysis of thin poly(3-Methylthiophene) and poly{(3-Methylthiophene)-co-[1-methyl-3-(pyrrol-1-ylmethyl)pyridinium]} films. Composition, oxidation level, and overoxidation
Analytical Chemistry, 1993Co-Authors: Peter G. PickupAbstract:X-ray emission spectroscopy (electron microprobe analysis) has been to determine CI:S atomic ratios in thin (0.1-5 μm) films of poly(3-Methylthiophene) and poly{(3-Methylthiophene)-co-[1-methyl-3-(pyrrol-1-ylmethyl)pyridinium]} on carbon and Pt electrodes. The composition of a copolymer films is given directly by the CI:S ratio for the reduced copolymer with perchlorate counterions. The thiophene content of the copolymers increases with increasing polymerization current density
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Reactivation of poly(3-Methylthiophene) following overoxidation in the presence of chloride
Journal of the Chemical Society Chemical Communications, 1992Co-Authors: Peter G. PickupAbstract:Poly(3-Methylthiophene) films made electrochemically inactive by overoxidation in the presence of Cl– can be reactivated both electrochemically and chemically to produce a partially chlorinated conducting polymer.
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In situ conductivity of poly-(3-Methylthiophene) and (3-Methylthiophene)x-[Ru(2,2'-bipyridine)2(3-{pyrrol-1-ylmethyl}pyridine)2]2+
Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1991Co-Authors: Jolanta Ochmanska, Peter G. PickupAbstract:Abstract The in situ electronic conductivities of poly(3-Methylthiophene) and (3-Methylthiophene) x -[Ru(bp) 2 (pmp) 2 ](ClO 4 ) 2 copolymers (bp = 2,2'-bipyridine, pmp = 3-(pyrrol-1-ylmethyl)pyridine) have been investigated by dual (sandwich) electrode voltammetry and rotating disc voltammetry. The experimental data have been treated using an ohmic conductivity model which takes into account the variation in conductivity across the film. The conductivity of the methylthiophene homopolymer increases exponentially with a slope of 96 mV/decade from ca. 10 −8 Ω −1 cm −1 at 0 V vs. SSCE to ca. 1 Ω −1 cm −1 at +0.8 V. Significant hysteresis is observed in the conductivity vs potential data; the conductivity of the polymer is generally higher during reduction than during oxidation at the same potential. Copolymerization of the Ru complex with 3-Methylthiophene results in films with a much lower conductivity at all potentials. In terms of an electron hopping model the Ru sites lead to a substantial decrease in the electron hopping rate between oxidized poly(3-Methylthiophene) sites. The maximum conductivity of the copolymer films decreases exponentially with increasing Ru concentration as predicted by such a model. A secondary effect of the Ru sites is to increase the average redox potential of the poly(3-Methylthiophene) so that higher potentials are required to produce charge carriers (oxidized sites).
Attila Yildiz - One of the best experts on this subject based on the ideXlab platform.
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Electropolymerization of thiophene and 3-Methylthiophene on PbO2 electrodes
Journal of Electroanalytical Chemistry, 2004Co-Authors: Serdar Abaci, Attila YildizAbstract:Abstract Aqueous electropolymerization of thiophene and 3-Methylthiophene was accomplished on β-PbO 2 electrodes. Poly 3-Methylthiophene films were also formed on α-PbO 2 surfaces under acidic conditions. It was also determined that the upper potential limit for thiophene electropolymerization could be lowered by about 400 mV using β-PbO 2 compared to the platinum electrode in pure acetonitrile, whereas this limit was lowered only by about 200 mV on the α-PbO 2 electrode. In the case of 3-Methylthiophene, the upper potential limit was decreased to 1.1 V vs. Ag|AgCl on the β-PbO 2 electrode and this lower limit was found to be 1.3 V vs. Ag|AgCl on the α-PbO 2 electrode. It was also shown that the polymorphic composition and degrees of crystallinities of PbO 2 films also influenced the extent of the electropolymerizations and the conductivity values.
Teketel Yohannes - One of the best experts on this subject based on the ideXlab platform.
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Poly(3-Methylthiophene-co-3-octylthiophene) based solid-state photoelectrochemical device
Journal of the Brazilian Chemical Society, 2007Co-Authors: Tesfalidet Lemma, Teketel YohannesAbstract:The copolymer, poly(3-Methylthiophene-co-3-octylthiophene), was electrochemically synthesized from a mixture of 3-Methylthiophene and 3-octylthiophene. Once the best condition for the copolymer formation was obtained a solid-state photoelectrochemical cell (PEC) was constructed and studied. The PEC contains the photoactive material poly(3-Methylthiophene-co-3-octylthiophene), poly(3MT-co-3OT), coated on indium doped tin oxide (ITO) coated glass, an amorphous poly(ethylene oxide), POMOE, an ion conducting polymer electrolyte complexed with I3-/I- redox couple and an electrochemically polymerized poly(3,4-ethylenedioxythiophene) (PEDOT) coated on ITO-coated glass as a counter electrode. An open-circuit voltage of 165 mV and a short circuit current of 0.21 µA cm-2 were obtained with light illumination of approximately 100 mW cm-2. Incident monochromatic photon-to-current conversion efficiency (IPCE%) of 0.51 for front side (ITO/PEDOT) illumination and 0.15 for backside (ITO/poly(3MT-co-3OT)) illumination at wavelength of 460 nm were obtained. In addition, dependence of the short circuit current and open circuit voltage on light intensity and time of illumination were studied.
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Electrochemical and spectroscopic characteristics of copolymers electrochemically synthesized from 3-Methylthiophene and 3,4-ethylenedioxy thiophene
Synthetic Metals, 1997Co-Authors: Teketel Yohannes, J.c. Carlberg, Olle Inganäs, Theodros SolomonAbstract:The copolymers poly(3-Methylthiophene-co-3,4-ethylenedioxythiophene) were prepared from mixtures of 3-Methylthiophene and 3,4-ethylenedioxythiophene via electrochemical oxidation. Various concentrations of the monomers in the mixture at a fixed polymerization potential, or fixed concentrations of the monomers in the mixture at various polymerization potentials were used to produce copolymers. Electrochemical and spectroscopic characterizations demonstrate the possibility of modulating continuously the electrochemical and optical properties of the individual polymers.
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Polymer-electrolyte-based photoelectrochemical solar energy conversion with poly(3-Methylthiophene) photoactive electrode
Synthetic Metals, 1996Co-Authors: Teketel Yohannes, Theodros Solomon, Olle InganäsAbstract:A photoelectrochemical cell based on neutral poly(3-Methylthiophene) electrochemically coated on indium—tin oxide as a photoactive electrode, an amorphous poly(ethylene oxide) complexed with an I3−/I− redox couple as a solid polymer electrolyte, and thin transparent platinum film vapour deposited on indium—tin oxide as a counter electrode has been constructed. At catholic potentials a cathodic photocurrent was obtained indicating that the neutral poly(3-Methylthiophene) is a p-type semiconductor. The short-circuit current and open-circuit voltage obtained with white light illumination at 100 mW cm−2 are 0.35 μA cm−2 and 140 mV, respectively. The monochromatic photon to current conversion efficiency obtained under illumination through back and front side is 0.3 and 0.6%, respectively. Studies of the photocurrent action spectra revealed that the poly(3-Methylthiophene)/solid polymer electrolyte junction is responsible for the photocurrent generation. The intensity and time dependence of the short-circuit current and open-circuit voltage have been studied.
