The reaction of 2-picoline N-Oxide with o-substituled benzoates and lsatoic anhydrides

The reaction of 2-picoline N-Oxide anion with o-substituted henzoates and isatoic anhydrides to give synthetically useful l-(2-methoxyphenyl)-2-(2-pyridinyl)ethanone N-oxides, I-(2-hydroxy-phenyJ)-2-(2-pyridinyl)ethanone N-oxides and I -(2-arninopheny])-2-(2-pyridinyl)ethanone N-oxides is described.     

Constituents of the root of Dictamnus albus L.

In addition to several known constituents and their artefacts, the root of Dictamnus albus L. has yielded the new natural products, isomaculosidine (9) and preskimmianine (15, R== Me).²¹     

Pulsed titration sensors: Part 1: A breath-by-breath CO2 sensor

A novel electrochemical sensor for the determination of CO₂ in expired breath is described. The sensor works by generating from the reduction of O₂ in dimethyl sulphoxide (DMSO) in a generating pulse. There is a rapid titration reaction between the and any CO₂ present. In the recovery pulse the amount of unreacted is determined. The larger the concentration of CO₂ the less is found in the recovery pulse. The solubilities and diffusion coefficients of O₂ and CO₂ in DMSO have been determined using rotating disc voltammetry and rotation speed step experiments. The stoichiometry, the product, and the rate constant of the titration reaction have been determined using ring—disc voltammetry and laser Raman spectroscopy. The operation and the effect of adventitious water on the sensor are described. Results are presented which show that the sensor can indeed measure the breath-by-breath rhythm of expired CO₂ from a human subject.     

Mixed halide complexes of lead. A comparison with theoretical predictions

Experimentally and theoretically derived formation constants of mixed lead halide complexes are compared at 25.0°C and one molar ionic strength. The formation constant of PbBrCl, ₁₁=79±10, is somewhat larger than the theoretical results, ₁₁=55, predicted using the formation constants of PbBr₂ and PbCl₂. The molar absorptivity of PbBrCl was observed to be intermediate in character between the molar absorptivities of PbBr₂ and PbCl₂. Determinations of the formation constants of PbBr₂Cl^– and PbBrCl₂ ^– are in reasonable agreement with the predictions based on the formation constants of PbBr₃ ^– and PbCl₃ ^–. Mixed ligand species dominated the complexation scheme of Pb(II) in our test media.     

The pentacyclopropylethyl carbocation

The synthesis of pentacyclopropylethanol and nmr of the corresponding cation is desbribed.     

New developments in the dye-doped polymer dispersed liquid crystals gratings: A review

In this study, the dye-doped polymer dispersed liquid crystals (PDLC) gratings techniques performed by the various research groups or being developed are briefly reviewed. Especially, the electrically switched diffraction and holographic gratings, have attained much attention by various research groups working in the PDLC-related display studies. The fabrication methodologies used for such grating texture, include like the conventional dye-doped PDLC grating, Azo-dye doped PDLC gratings, and lasing techniques etc., adopted for dye-doped PDLC gratings. The useful features and characteristics of their fabrication process of such gratings are discussed. Finally, some of the future perspectives on this particular research field are presented.