A phosphonated triarylmethyl radical as a probe for measurement of pH by EPR

A new water soluble phosphonated tetrathiatriarylmethyl radical has been synthesized and its application for pH measurement in a physiological range by EPR is reported.     

Synthesis of CeO2@SiO2 core-shell nanoparticles by water-in-oil microemulsion. Preparation of functional thin film

Synthesis of nanoparticles under restricted environment offered by water-in-oil (W/O) microemulsions provides excellent control over particle size and shape, and inter-particle spacing. Such an environment has been involved to synthesize silica nanoparticles with a CeO2 core, so-called CeO2@SiO2. Aqueous fluids made up of ceria nanoparticles with a size close to 5 nm have been used as the water phase component. The starting CeO2 sols and obtained CeO2@SiO2 nanoparticles have been characterized by dynamic light scattering (DLS), X-ray diffraction, scanning and transmission electron microscopy, and specific surface area measurements. The microemulsion process has been characterized by DLS. Preliminary results on CeO2@SiO2 thin films are presented.     

5‐aminothiazolium salts as potential cyclic azomethine ylides: Base‐induced cycloaddition reactions with aryl,alkyl, and benzoyl isothiocyanates

Reactions of the in situ generated thiazoles 2 with aryl and alkyl isothiocyanates appear to be totally regioselective and give the unexpected 5‐(phenylthio)imidazolium‐4‐thiolates 3 . Such rapid interconversion of mesoionic compounds is explained by a 1,3‐dipolar addition to the C=N bond of the heterocumulene followed by tBuNCS elimination. Similar interactions with benzoyl isothiocyanate exclusively proceed on the C=S unsaturation of the heteroallene moiety and produce the 4‐(phenylthio)thiazolium‐5‐amidines 12 . Structural assignment of isolated imidazoles and thiazoles is based on ¹³C NMR data and chemically confirmed by the NaBH₄ reduction of the alkylated derivatives 5 and 13 . Efforts to isomerize the starting mesoionic thiazole 2a without the use of tBuNCS are unsuccessful. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 10:16–26, 2000