Electrochemical catalytic dechlorination of polychlorinated benzenes was achieved by use of an electrode coated with a film of poly [N-(6-aminohexyl) pyrrole] and Pd in 50% alcoholic solutions containing an alkali metallic salt. The dechlorination of the chlorinated benzenes achieved high benzene yield through the production of intermediate chlorinated benzenes.
Palladium/2,2,6,6-tetramethylpiperidine-1-oxyl (Pd/TEMPO) double-mediatory electrooxidative Wacker-type cyclization of 1 was developed. In a mixture solution of dioxane and water, the reaction efficiently proceeded at room temperature to give benzofuran derivative 2.
Electroreduction of N,N′-dioctyl-4,4′-bipyridinium (C8V2+) bis(triflimide) was carried out in ionic liquids to give the corresponding quinoid C8V0, which promoted reductive coupling of aryl halides in the presence of a Pd catalyst to give biaryls. C8V2+ and the ionic liquids were used repeatedly.
We have developed vapor-deposited films of acenaphtho[1,2-k] fluoranthene (AF) and their 7,14-dicarbalkoxy derivatives as active layers of organic field-effect transistors (OFETs). The AF- and 7,14-dicarbmethoxyacenaphtho[1,2-k] fluoranthene (DMAF)-based OFET devices did not work sufficiently. On the other hand, the 7,14-carbethoxyacenaphtho[1,2-k] fluoranthene (DEAF)-based OFET device showed typical p-channel FET responses with a field-effect mobility of 1.7×10−3 cm2 V−1 s−1 and a current on/off ratio of about 102. According to the X-ray diffraction measurements, the carbethoxy groups could largely improve the molecular packing that is favorable for high-performance OFETs.
The structural and electrochemical properties of Ag cubic-particles supported on highly oriented pyrolytic graphite (HOPG) have been studied using atomic force microscopy (AFM) and voltammetry. Ag cubic-particles aggregate in an array on HOPG in solution. The AFM image of the Ag particles is similar to that obtained using transmission electron microscopy. Voltammogram of the Ag particles on HOPG electrode gives a pair of peaks at around −0.7 V (Ag/AgCl) in NaBr solution, which corresponds to the order-disorder structural transition of Br layer adsorbed on Ag(100) electrode. The surface structure and electrochemical properties of Ag cubic-particles are similar to those of Ag(100).
An unstable phenoxonium cation generated by the anodic oxidation of 4-methoxyphenol was observed by cyclic voltammetry. Electrochemical studies of the anodic electron transfer demonstrated the media effect of electrolyte solutions for achieving cycloaddition reactions between the electrochemically generated phenoxonium cation and alkenes.
Anodic oxidation of a furan derivative was accomplished in cycloalkane-based thermomorphic (CBT) electrolyte solutions. In the CBT system, hydrophobic phase-tagged substrates were efficiently electrolyzed in the reversibly immixed mono-phasic state followed by on-cooling phase-separation of the tagged product as the cycloalkane solution separated from the polar electrolyte solutions. In the case of anodic oxidation of the phase-tagged furanyl compound, a 3,5-didocosyloxybenzyl tag that possessed higher oxidation potential and high hydrophobicity worked efficiently for achieving the selective anodic oxidation of the furanyl moiety. The electrolytic products were also successfully subjected to catalytic hydrogenation, which is generally difficult for solid-supported substrates. The product was separated from the CBT electrolyte solution simply by on-cooling phase separation.
Deterioration rate of a lithium-ion battery can be accelerated by the existence of an extra positive electrode (P2) where does’t face to the negative electrode. Therefore, the size of the positive electrode (P1) is designed smaller than the size of the negative electrode (N1) with a lithium-ion battery. However, the mechanism was not yet made clear. Eight reference electrodes were embedded around a cell which connected with P2 through an ammeter, and electrical potential behavior in a horizontal plane of the cell was studied against the nearest reference electrode. When the charge and discharge of the cell was performed, remarkable potential shifts occurred and the electricity charged from P1 to P2 was observed. Electric potential distributions in a horizontal plane of the cell were also analyzed with contour maps. Lithium ions must be supplied from P2 to N1 when the charge of the cell is performed and they must be also supplied from P2 to P1 when it discharges. The ion conduction resistance between P2 and P1 was estimated as 250 Ω.
Alkaline polymer gel electrolytes mainly with modified polyvinyl alcohol (PVA) have been prepared for an electric double layer capacitor (EDLC). Their electrochemical characteristics were evaluated by impedance spectroscopy and constant-current charge/discharge measurement. The prepared gel electrolyte film with KOH exhibits excellent flexibility and an ionic conductivity of about 7×10−2 S cm−1 at 298 K. The gel electrolyte EDLC shows comparable discharge capacitance to that for EDLC containing a conventional aqueous electrolyte. These results suggest that the gel electrolyte based on the modified PVA is promising material for use in EDLC.
A new pathway to germane-stannane copolymers is reported here. Diphenylgermyl dianion and methylphenylgermyl dianion were generated and accumulated in the cathode compartment of the two compartment cell by electrochemical reduction of diphenylgermane and methylphenylgermane, respectively, at −50°C in DMF using tetrabutylammonium tetrafluoroborate as a supporting electrolyte. These anions gave germane-stannane copolymers upon the reaction with dibutyldichlorostannanes. The obtained copolymers showed less sensitive characteristics toward the moisture compared to poly(dibutylstannane), and photodecomposition as sensitive as poly(dibutylstannane).
Highly regioselective anodic monofluorination of 3H-1,4-benzoxathian-2-ones was successfully carried out using anodically stable Et4NF·4HF as supporting electrolyte and fluorine source to provide the corresponding monofluorinated products in good yields while anodically less stable supporting electrolyte, Et3N·3HF, gave only poor yields.