Hydrophilic polymer supported nanoparticles prepared from samarium trichloride and lanthanum trichloride in liquid-phase

Nanoparticles were obtained by the reaction of SmCl₃·6H₂O with sodium borohydride (NaBH₄) in the presence of sodium polyacrylate (PAA) with average molecular weight of 5,100 as a capping polymer. The resulting colloidal solution was placed on a Cu grid and characterized by transmission electron microscope (TEM) measurement, which clearly indicated the generation of nanoparticles. The reaction of LaCl₃ with NaBH₄ in the presence of PAA led to preparation of lanthanum nanoparticles, similarly as samarium nanoparticles.     

Highly enantioselective reformatsky reaction of ketones: chelation-assisted enantioface discrimination

[reaction: see text] Highly enantioselective Reformatsky reaction of ketones was accomplished using cinchona alkaloids as chiral ligands. Chelation with the sp(2)-nitrogen adjacent to the reactive carbonyl center contributed the enantioface discrimination for the high enantioselectivities.     

Centrifugal concentrator for the substitution of nitrogen blow-down micro-concentration in dioxin/polychlorinated biphenyl sample preparation

A centrifugal concentrator was applied for the substitution of nitrogen blow-down micro-concentration in dioxin/PCB sample preparation. Automation was achieved through this apparatus and resulted in significant improvements in sample preparation productivity, along with excellent reproducibility and recovery rate of dioxin/PCB. Mean recoveries of dioxin congeners were 90-106%, respectively.     

Possible spin triplet superconductivity in NaxCoO2.yH2O

Symmetry-based considerations are combined with inputs from available experimental results to make the case that a novel spin-triplet superconductivity triggered by antiferromagnetic fluctuations may be realized in the newly discovered layered cobaltide NaxCoO2.yH(2)O. In the proposed picture, inaccessible via resonating-valence-bond physics extrapolated from half-filling, the pairing process is similar to that advanced for Sr2RuO4, but enjoys a further advantage coming from the hexagonal structure of the Fermi surface which gives a stronger pairing tendency.     

Observation of fluorescence in an optically pumped erbium-containing perfluorinated medium at 1.5 microm

We report what is to our knowledge the first observation of erbium fluorescence at the optical communication wavelength of 1.5 microm in a perfluorinated medium. Using a Nd:YAG (355-nm) source, we observed fluorescence of the 4I(13/2) - 4I(15/2) transition with a peak wavelength of 1.535 microm and with a full width at half-maximum of 28 nm. These results can lead to new active devices that use all-fluorinated polymers.     

Brønsted acid-base ionic liquids and their use as new materials for anhydrous proton conductors

Novel Br?nsted acid-base ionic liquids, derived from a simple combination of a wide variety of organic amines with bis(trifluoromethanesulfonyl) amide are electroactive for H2 oxidation and O2 reduction at a Pt electrode under non-humidifying conditions, which shows the prospect of the use of protic ionic liquids as new materials for anhydrous proton conductors at elevated temperatures.     

Functionalization on silica gel with allylsilanes. A new method of covalent attachment of organic functional groups on silica gel

Treatment of an (allyl)organosilane with silica gel in refluxing toluene brought about deallylation forming an Si-O-Si bond with the silicon on the silica gel. This Si-O-Si bond formation provides us with a new reliable method for the functionalization of a silica gel surface.     

Ionicity of intramolecular charge-transfer molecule Ddelta+-pi-Adelta- based on 1,3,3-trimethyl-2-methyleneindoline and 7,7,8,8-tetracyanoquinodimethane

We report a simple and convenient method to evaluate the relative ionicity delta of the typical intramolecular charge-transfer (CT) molecules linked by pi-bond Ddelta+-pi-Adelta- (D, donor; A, acceptor; delta, degree of CT) derived from 1,3,3-trimethyl-2-methylene indoline and TCNQ derivatives on the basis of the solvatochromic effects of the CT band in various solvents and their redox properties. The functionality of the intramolecular CT molecules as dyes, photovoltaic materials, nonlinear optics, rectifiers, and conductors is discussed in terms of delta.     

Mechanistic study on mechanochemical polymerization of acrylamide

The ESR study of the radicals formed in mechanochemical polymerization of acrylamide (AAM) was undertaken. The nature of the radical formation was compared with the mechano-radical formation produced by mechanical fracture of polyacrylamide (PAAM). The structure of radicals formed were all identified to be an end-chain radical, equivalent to a polymer-chain propagating radical. The computer simulation disclosed that the observed spectra of the propagating radical can be approximated essentially by two kinds of component spectra, a large amount of triplet, and a small amount of quarter (a triplet of doublets). Thus, the existence of two major conformers in a single end-chain radical has been proposed. The ESR kinetics of the radical formation were further studied and its correlation with the nature of polymerization (the changes in molecular weight and polymer conversion) was discussed.     

Some reactions of mono substituted pyrazine monoxides

The reactions of the monoxides of propylpyrazine and phenylpyrazine with phosphoryl chloride or acetic anhydride were investigated. Except in the case of the reaction of 2-propylpyrazine 1-oxide with acetic anhydride, chlorination or acetoxylation occurred on the pyrazine ring in all cases; moreover, these reactions occurred preferentially at the position poorest in π-electron density. The N-oxidation and the successive chlorination of monochloro-phenylpyrazines were also investigated, and the structures of the products were confirmed.