Influence of nano-structure on electrolytic properties in CeO2 based system

Doped ceria (CeO₂) compounds are fluorite type oxides that show oxygen ionic conductivity higher than yttria stabilized zirconia, in oxidizing atmosphere. In order to improve the conductivity, the effective index was suggested to maximize the oxygen ionic conductivity in doped CeO₂ based oxides. In addition, the true microstructure of doped CeO₂ was observed at atomic scale for conclusion of conduction mechanism. Doped CeO₂ had small domains (10-50 nm) with ordered structure in a grain. It is found that the electrolytic properties strongly depended on the nano-structural feature at atomic scale in doped CeO₂ electrolyte. This revised version was published online in August 2006 with corrections to the Cover Date.     

Determination of trace amounts of vanadium in air samples with 2-(8-quinolylazo)-5-N,N-diethylaminophenol by reversed-phase liquid chromatography

A reversed-phase liquid chromatographic method for the determination of trace amounts of vanadium is described. Metal ions are converted into 2-(8-quinolylazo)-5-N,N-diethylaminophenol chelates in an off-line system. The chelates are injected onto a Zorbax CN column and separated with an aqueous acetonitrile mobile phase containing no chromogenic reagent. Unter these conditions, only vanadium(V) is spectrophotometrically detected at 540 nm among the metal ions Al(III), Ba(II), Ca(II), Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Ga(III), Hg(II), Mg(II), Mn(II), Ni(II), Pb(II), V(V) and Zn(II). Amounts of 8.0–200 pg of vanadium(V) in 100-μl injections can be determined without interference from 10-fold molar excesses of many cations. At 0.001 a.u.f.s., the detection limit (twice the peak-to-peak noise) for vanadium(V) is 8.0 pg in 100 μl of injected solution and the relative standard deviation at 120 pg of vanadium(V) in a 100-μl injection is 3.5%. The proposed method is applied to the determination of vanadium in rain water and airborne particulates.     

Modification of poly(vinyl chloride). XIII. Crosslinking of poly(vinyl chloride) with dithiols and properties of the crosslinked products

PVC was crosslinked by immersing PVC–dithiol blends in ethylenediamine at 30°C. Properties of the products depended on the chain length and chemical structure of the crosslinkage and on the molecular weight of the polymer chain between crosslinks M_c. Crosslinking by the agent of soft structure and long molecular chain resulted in high tensile strength at break and impact strength and low brittle temperature. The use of the crosslinking agent of short molecular chain gave high yield strength, Young's modulus, and heat distortion temperature. The relation of M_c and the chemical structure of the crosslinks to the properties of the crosslinked rigid polymer was discussed in regard to the crosslinking effect and plasticizing effect.     

Profiling analysis of oligosaccharides in antibody pharmaceuticals by capillary electrophoresis

Carbohydrate chains in glycoprotein pharmaceuticals have important roles for the expression of their biological activities. Therefore, development of an assessment method for the carbohydrate chains is an important parameter for quality control of glycoprotein pharmaceuticals such as newly developed therapeutic antibodies. In this report, we applied capillary electrophoresis with laser-induced fluorescence detection to the analysis of carbohydrate chains after releasing with glycoamidase followed by derivatization with 3-aminobenzoic acid. We found that four major oligosaccharides present in antibody pharmaceuticals were successfully separated with good resolution. The present method showed good precision in both migration times and relative peak areas, and gave comparable accuracy with that using a derivatization method with 8-aminopyrene-1,3,6-trisulfonate.     

Synthesis of the enantiomers of cis-2-methyl-5-hexanolide,the major component of the sex pheromone of the carpenter bee

(2R,5S)-2-Methyl-5-hexanolide and its antipode were synthesized in highly optically pure state (?98–99% e.e.) starting from ethyl (S)-lactate and the enantiomers of methyl β-hydroxyisobutyrate. The specific rotations of our samples were [α]_D±91.0-93.5° (CHCl₃), while the reported values of the samples prepared by resolution or asymmetric synthesis were ±64.5–65.6°.     

Reaction of α-haloester having internal double bond with the low-valent metal complex

The α-haloester having an internal double bond was allowed to react with a catalytic amount of Pd(PPh₃)₄ to afford a cyclized product in a fairly good yield and the same product was obtained by treatment with Pd(OAc)₂ to ketene silyl acetal.     

Chlorovulones,new halogenated marine prostanoids with an antitumor activity from the stolonifer clavularia viridis Quoy and Gaimard

New halogenated marine prostanoids, chlorovulone I, II and III were isolated from the stolonifer $\text{Clavularia}$$\text{viridis}$ Quoy and Gaimard. The structure elucidation and the antitumor activity of chlorovulones were described.     

Pheromone synthesis—63 Synthesis of both the enantiomers of 2,3-dihydro-2- isopropyl-2,5-dimethylfuran,a sex specific compound in females of the beetle hylecoetus dermestoidesL

Both the enantiomers of 2,3-dihydro-2-isopropyl-2,5-dimethylfuran were synthesized employing the Sharpless asymmetric epoxidation reaction. The (R)-(—)-enantiomer of this cyclic enol ether was also synthesized starting from (R)-(—)-linalool.     

A facile synthesis of 1-cycloalkenyl isothiocyanates with silicon tetraisothiocyanate

The reaction of cycloalkanones with silicon tetraisothiocyanate in the presence of (Me₃SiO)₂SO₂^?nBu₃SnF or Zn(NCS)₂ provides 1-cycloalkenyl isothiocyanates in good yields under mild conditions.