Redetermination of bis{[(2‐hydroxy­phenyl­methyl)­bis(2‐pyridyl­methyl)­aminato]copper(II)} diperchlorate

The structure of the title compound, [Cu₂(C₁₉H₁₈N₃O)₂](ClO₄)₂, was reported with insufficient accuracy because of a twinning problem by Adams, Bailey, Campbell, Fenton & He [J. Chem. Soc. DaltonTrans. (1996), pp. 2233–2237]. The dinuclear phenolate‐bridged Cu^II complex has an inversion centre.     

Chloro­[N′,N′‐diethyl‐N,N‐bis(2‐pyri­dyl­methyl)­ethyl­enedi­amine‐κ4N]copper(II) perchlorate

The title mononuclear copper(II) complex, [CuCl(C₁₈H₂₆N₄)]ClO₄, shows a square‐pyramidal coordination with the diethyl­amino N atom at the apical position. Large anisotropies in the displacement parameters of the non‐H atoms of the ligand seem to be due to rotational disorder of the ClO₄^? anion.     

Tetra‐μ‐acetato‐O:O′‐bis­[(7‐aza­indole‐N)­copper(II)]

The title complex, [Cu₂(C₂H₃O₂)₄(C₇H₆N₂)₂], shows a binuclear cage structure having an inversion centre. There are intramolecular N—H?O hydrogen bonds between the 7‐aza­indole ligands and the bridging acetate O atoms.     

Aerobic Dehydrogenation of N-Heterocycles with Grubbs Catalyst: Its Application to Assisted-Tandem Catalysis to Construct N-Containing Fused Heteroarenes

An aerobic dehydrogenation of nitrogen-containing heterocycles catalyzed by Grubbs catalyst is developed. The reaction is applicable to various nitrogen-containing heterocycles. The exceptionally high functional group compatibility of this method was confirmed by the oxidation of an unprotected dihydroindolactam V to indolactam V. Furthermore, by taking advantage of the oxygen-mediated structural change of the Grubbs catalyst, we integrated ring-closing metathesis and subsequent aerobic dehydrogenation to develop the novel assisted-tandem catalysis using molecular oxygen as a chemical trigger. The utility of the assisted-tandem catalysis was demonstrated by the concise synthesis of N-containing fused heteroarenes including a natural antibiotic, pyocyanine.     

Ionic Dopant‐Encapsulating Single‐Walled Carbon Nanotube Films with Metal‐Like Electrical Conductivity

Heavy doping is inevitable for utilizing single‐walled carbon nanotubes for wiring. However, the electrical conductivity of their films is currently as low as one tenth of the films made from typical metal pastes. Herein we report on metal‐comparable electrical conductivity from single‐walled carbon nanotube network films. We use ionic liquids and crown ether complexes for p‐type and n‐type doping, respectively. The encapsulation of counterions into carbon nanotubes promotes the conductivities in the range of 7000 S cm^?1, approximately ten times larger than those of undoped films.     

Kinetic analysis of distribution of weak acid in an oil-gelatin microcapsule/water system studied by microcapillary injection and microabsorption methods.

The distribution of anthracene-9-carboxylic acid across dibutyl phthalate/gelatin-membrane/water interface of a single microcapsule was analyzed using microcapillary manipulation and microabsorption methods. The partitioning ratio and the distribution rate in the microcapsule/water system were measured for various pH values in the water phase. Results were compared with those in the dibutyl phthalate/water system in the absence of the gelatin membrane. The distribution rate could be analyzed on the basis of a first-order type reaction. The observed rate constant was linearly proportional to the inverse of the microcapsule radius, indicating that the distribution rate is limited by interfacial mass transfer. Analysis of the pH dependence of the interfacial mass transfer rate suggests that the mass transfer of the neutral species of anthracene-9-carboxylic acid (AnH) competes with the ion transfer of the dissociated species (An-) at the liquid/liquid interface in the gelatin membrane of the microcapsule.     

Synthesis of 2-phenylimidazo[2,1-b]benzothiazole derivatives as modulators of multidrug resistance for tumor cells

We have investigated 3-substituted-2-phenylimidazo[2,1-b]benzothiazole derivatives and herein we have discussed their pharmaceutical activities. We found that some 2-phenyl-5,6,7,8-tetrahydroimidazo[2,1-b]-benzothiazoles could overcome multidrug resistance for tumor cells. Among them, 2-phenyl-3-(N-methyl-3-piperidyl)carbonylammomiinomemyl-5,6,7,8-tetrahydVoimidazo[2,1-b]benzothiazole [N276-12] demonstrated the most potent activity for overcoming multidrug resistance.     

A single-electron circuit as a discrete dynamical system

A single-electron circuit can be operated as a discrete dynamical system because it changes its internal state discontinuously because of electron tunneling. To confirm this idea, we designed a sample circuit for discrete dynamical operation and confirmed by computer simulation that the circuit successfully generated a sequence of discrete-time outputs by following a return map. The concept of discrete dynamical systems will be useful in developing new functional systems that consist of quantum devices and nanostructures.