Self‐Assembled Fibers Containing Stable Organic Radical Moieties: Alignment and Magnetic Properties in Liquid Crystals

Macroscopically oriented stable organic radicals have been obtained by using a liquid–crystalline (LC) gel composed of an l ‐isoleucine‐based low molecular weight gelator containing a 2,2,6,6‐tetramethylpiperidine 1‐oxyl moiety. The LC gel has allowed magnetic measurements of the oriented organic radical. The gelator has formed fibrous aggregates in liquid crystals via intermolecular hydrogen bonds. The fibrous aggregates of the radical gelator are formed and oriented on cooling by applying a magnetic field to the mixture of liquid crystals and the gelator. Superconducting quantum interference device (SQUID) measurements have revealed that both oriented and nonoriented fibrous aggregates exhibited antiferromagnetic interactions, in which super‐exchange interaction constant J is estimated as ?0.89 cm^?1.     

Abnormal Li diffusion in β-LiGa by the formation of defect complex

The diffusion coefficients of Li in the NaTl-type Li intermetallic compound of β-LiGa have been measured by using a short-lived radioactive diffusion tracer. As the tracer, the α-emitting radioisotope of ⁸Li delivered as the energetic and pulsed beam from Tokai Radioactive Ion Accelerator Complex (TRIAC) was implanted into the β-LiGa compounds with the composition in the range of about 43 to 54 at.% Li. By analyzing the time-dependent yields of the α-particles measured according to the repetition cycle of the beam, the tracer diffusion coefficients were extracted over the wide range of Li composition. Abnormal composition-dependence of Li diffusion coefficients in β-LiGa was observed; the stoichiometric β-LiGa showed the highest diffusivity of Li. By referring to the composition-dependent diffusivity of Li in the iso-structural β-LiAl and β-LiIn, we could identify the abnormal diffusion of Li in very Li-poor composition of β-LiGa. The anomaly has been discussed qualitatively in terms of the formation of defect complex and the interaction between the constitutional defects.     

Voltammetric Determination of Boric Acid Using the Ternary Complexation System with Salicylaldehyde and H‐Acid

A square‐wave voltammetric method for the determination of boric acid in water has been described based on the new understanding of the electrochemical behavior of boric acid‐Azomethine H complexation. Salicylaldehyde and H‐acid were used as the starting materials of boric acid‐Azomethine H complex and their concentrations were optimized for boric acid determination in water. A glassy carbon electrode, instead of a conventional mercury electrode, was used in the measurement. The detection limit of the proposed method was 0.10 mg B dm^?3. The proposed method was successfully used for boric acid determination in the water from a seawater desalination RO plant.     

Chemoselective Oxidation of Secondary Hydroxy Functions Catalyzed by [PMo12O40]3-[C5H5N+(CH2)15 CH3]3

Abstract

The epoxidation of allylic alcohols with H₂O₂ catalyzed by a new Mo-species, [PMo₁₂O₄₀]^3?[C₅H₅N⁺(CH₂)₁₅CH₃]₃ (MPCP), prepared from 12-molybdatophosphoric acid (H₃PMo₁₂O₄₀) and cetylpyridinium chloride [C₅H₅N⁺(CH₂)₁₅CH₃ · Cl^?], has recently rep0rted.) The high regioselectivity for the epoxidation by this MPCP-H₂O₂ system was comparable to that of Sharpless method using t-BuOOH as oxidant.     

Ketonization of Secondary Hydroxy Groups of Alcohols and Diols with Hydrogen Peroxide Under the Influence of Tricetylpyridinium-12-Tungstophosphate

Molydbenum and tungsten-catalyzed oxidations of alcohols with dilute hydrogen peroxide under phase-transfer conditions have been focused in recent years 1–3. In a previous paper, we have reported that tricetylpyridinium-12-molybdophosphate(CMP), [π - C₅H₅N+(CH_{2 15}CH₃]₃ (PMO₁₂O₄₀)³-, prepared from 12-molybdophosphoric acid (MPA) and cetylpyridinium chloride (CPC), catalyzed the oxidation of secondary alcohols to carbonyl compounds with tert-butylhydroperoxide(t-BuOOH)⁴. When hydrogen peroxide in place of t-BuOOH was employed as the oxidant for the above oxidation, however, alcohols were oxidized with difficulty to give carbonyl compounds in poor yields. In continuation of this study, we wish to report here the selective oxidation of secondary hydroxy group of alcohols and diols and diols with H₂O₂ under the influence to tricetylpyridinium-12 tungstophosphate (CWP), [π-C₅H₅N+ (CH₂) 15 CH₃]₃(PW₁₂O₄₀)³-, derived from 12-tungstophosporic acid (WPA) and CPC.     

Universal fluorescent labeling of amplification products using locked nucleic acids

Amplification/hybridization‐based genetic analyses using primers containing locked nucleic acids (LNAs) present many benefits. Here, we developed a novel design for universal fluorescent PCR using LNAs. Universal fluorescent PCR generates intermediate nonlabeled fragments and final fluorescent fragments in a two‐step amplification process that uses locus‐specific primers with universal tails and universal fluorescent primers. In this study, a few standard nucleotides were replaced with LNAs only in the fluorescent universal primers. The sequence of the fluorescent universal primer significantly affected the amplification efficiency. For primers with three LNAs, the fluorescent primers with stable M13(‐47) sequences provided the most efficient signal (approximately tenfold higher than the primers with M13(‐21) sequences at lower Tm values). Moreover, AT‐rich LNA substitutions in the fluorescent primers produced much lower amplification efficiencies than GC‐rich substitutions. GC‐rich LNAs produced greater differences in Tm values among primers, and resulted in the preferential production of fluorescently labeled amplicons. The specificity and sensitivity of LNA‐containing fluorescent primers were assessed by genotyping eight STRs in Japanese individuals, and full STR profiles could be generated using as little as 0.25 ng of genomic DNA. The method permitted clear discrimination of alleles and represents sensitive STR genotyping at a reduced cost.     

Bimetallic Co–Pd alloy nanoparticles as magnetically recoverable catalysts for the aerobic oxidation of alcohols in water

Co–Pd bimetallic alloy nanoparticle catalysts were prepared from CoCl₂, Pd(OAc)₂ and several capping agents with Li(C₂H₅)₃BH. The nanoparticle catalysts were applied to the aerobic oxidation of a variety of alcohols in water to give the corresponding carbonyl products. The catalyst was magnetically recovered and reused for further oxidation. The nanoparticle catalysts were characterized with TEM, ICP, and XPS analyses.