Toshio Fuchigami

Electropolymerization of pyrrole in 1-ethyl-3-methylimidazolium trifluoromethanesulfonate room temperature ionic liquid

Abstract Air and moisture stable ionic liquid like 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMICF 3 SO 3 ) has been used as an electrolyte for the electrooxidative polymerization of pyrrole; the morphological structure of polypyrrole film formed on the anode was greatly affected, and the polymerization rate, electrochemical capacity and electroconductivity were significantly increased. Furthermore, it was also found that EMICF 3 SO 3 could be recovered by a simple extraction of the remaining pyrrole monomer from the ionic liquid after use, and then reused without significant loss of reactivity for the polymerization.

Electrooxidative polymerization of aromatic compounds in 1-ethyl-3-methylimidazolium trifluoromethanesulfonate room-temperature ionic liquid

Abstract Electrooxidative polymerization of aromatic compounds such as pyrrole, thiophene and aniline was carried out in air-and moisture-stable ionic liquid, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMICF3SO3). The polymerization rate and morphological structure of polymer films formed on the anode were affected, and the electroconductivity was significantly increased. Furthermore, the polypyrrole film prepared in EMICF3SO3 was applied to a matrix for hosting catalyst particles electrodeposited.

Gradient Doping of Conducting Polymer Films by Means of Bipolar Electrochemistry

In this paper, we report a novel electrochemical doping method for conducting polymer films based on bipolar electrochemistry. The electrochemical doping of conducting polymers such as poly(3-methylthiophene) (PMT), poly(3,4-ethylenedioxythiophene) (PEDOT), and poly(aniline) (PANI) on a bipolar electrode having a potential gradient on its surface successfully created gradually doped materials. In the case of PEDOT film, the color change at the anodic side was also observed to be gradually transparent. PANI film treated by the bipolar doping gave a multicolored gradation across the film. The results of UV-vis and energy dispersive X-ray analyses for the doped films supported the distribution of dopants in the polymer films reflecting the potential gradient on the bipolar electrode. Furthermore, the reversibility of the bipolar doping of the PMT film was demonstrated by a spectroelectrochemical investigation.

Degradation and its prevention, and the deactivation and reactivation of electroactive polythiophene films during oxidation/reduction cycles

Abstract A polythiophene film prepared on a Pt electrode was degraded and deactivated by repeating the potential scan in electrolytic solutions including nucleophiles and bulky cations, respectively. In the cases of the degradation and the deactivation, the anodic peak current and potential of the cyclic voltammogram decreased and shifted positively, respectively. The degradation could be prevented by keeping nucleophilic species out of the solutions and by adding strong acids, sterically hindered phenols or methoxylated benzenes, while the deactivation was also prevented by using alkali metal salt supporting electrolytes and by adding ferricinium or tritylium salt. Once deactivated the film could also be reactivated by polarizing at a highly positive potential. The mechanisms of the degradation, deactivation and reactivation are also discussed.

Selective electrochemical fluorination of organic molecules and macromolecules in ionic liquids

This article provides an outline of recent studies on selective electrochemical fluorination in ionic liquid fluoride salts toward green sustainable chemistry. First, a brief historical background of electrochemical fluorination in organic solvents is provided, and some particular problems and unique solvent effects associated with this technique are briefly mentioned. Second, recent progress in selective fluorination and fluorodesulfurization of organic molecules and macromolecules in ionic liquids using direct and indirect electrolysis with recyclable mediators is reviewed.

Use of Task-Specific Ionic Liquid for Selective Electrocatalytic Fluorination

Highly selective indirect anodic fluorination of organic compounds was successfully carried out for the first time by using a task-specific ionic liquid of iodoarene as a mediator in ionic liquid hydrogen fluoride salts.

Electroorganic synthesis under solvent-free conditions. Highly regioselective anodic monofluorination of cyclic ethers, lactones, and a cyclic carbonate

Abstract Regioselective anodic fluorination of cyclic ethers, lactones, and a cyclic carbonate in Et 4 NF· n HF ( n =4, 5) and Et 3 N·5HF without a solvent was successfully carried out to give the corresponding monofluorinated products in moderate yields. This is the first report of direct electrochemical fluorination of cyclic ethers, lactones, and a cyclic carbonate using anodic fluorination.

Electrolytic partial fluorination of organic compounds. 20. Electrosynthesis of novel hypervalent iodobenzene chlorofluoride derivatives and its application to indirect anodic gem-difluorination

Abstract Electrosynthesis of novel hypervalent iodobenzene chlorofluorides was successfully performed for the first time and it was demonstrated that p -methoxyiodobenzene chlorofluoride could be used as a mediator for indirect anodic gem -difluorination of dithioacetals.

Electrolytic partial fluorination of organic compounds. 3. Regioselective anodic monofluorination of organoselenium compounds and their synthetic application

Abstract Regioselective anodic α-monofluorination of selenides bearing electron-withdrawing groups such as cyano, ester, and amide groups was successfully performed. Highly stereoselective synthesis of α-fluoro α,β-unsaturated esters was achieved by using an α-fluoro α-selenoester prepared.

Electrolytic partial fluorination of organic compounds ☆: Part 44. Anodic gem-difluorodesulfurization using triarylamine mediators

Indirect anodic gem-difluorodesulfurization of dithioacetals was successfully carried out using triarylamine mediators to provide gem-difluoromethylene compounds in moderate to good yields.