Cyclizing Radical Carboiodination,Carbotelluration, and Carboaminoxylation of Aryl Amines

Radical carboiodination of various aryl amines is reported. Aryl diazonium salts, generated in situ from the corresponding aryl amines, are reacted with Bu₄NI to provide the corresponding aryl radicals which undergo 5‐exo or 6‐exo cyclization. Iodine abstraction eventually affords the carboiodinated products in good to excellent yields. If TEMPO is added, the cascade provides the cyclized carboaminoxylation products. Running the reaction in the presence of PhTeTePh affords the phenyltellurated cyclized products.     

Estimation of the surface energetic heterogeneity of fillers by inverse gas chromatography

The surface properties of the fillers are determining for obtaining high performance filled polymers. Yet, their determination is most difficult. This paper proposes to use inverse gas chromatography, either at infinite dilution or finite concentration conditions, to estimate surface energy and nanomorphological characteristics, but also surface heterogeneity of different clays, talcs of various origins and ground muscovites.     

Precipitation of inorganic salts inside hollow micrometer-sized polyelectrolyte shells

Hollow polymer shells formed by layer-by-layer adsorption of oppositely charged polyelectrolytes onto micrometer-sized colloidal particles with subsequent decomposition of the colloidal core were employed as a model system for the study of inorganic crystallization reactions in restricted volumes. The size-selective permeability of shells is used for spatially controlling the precipitation of inorganic salts CaCO3 and BaCO3 into the shell interior. Outside the shells the precipitation was suppressed by the polymers, which are unable to penetrate the shell wall. The precipitates were studied by scanning electron microscopy and atomic force microscopy. The fundamental and applied aspects of research on spatially confined synthesis of inorganic particles are under discussion.     

Libraries of composite polyfluors built from fluorescent deoxyribosides

We report on a new class of water-soluble fluorescent molecules (polyfluors) that are composed of multiple individual fluorophores assembled on a DNA-like backbone. Four fluorophore deoxyribosides were synthesized, and these individual molecules were assembled into oligofluor strings on a DNA synthesizer. A library of 256 tetrafluors was generated by split and pool methods on polystyrene beads. Images of the library under a fluorescence microscope revealed at least 40-50 different hues and intensities. Selected tetrafluors were resynthesized in pure form in solution and displayed properties, such as large Stokes shifts, that individual fluorophores do not have.