Synthesis and Characterization of Co3O4 Nanoparticles by Thermal Treatment Process

The simple preparation of Co₃O₄ nanoparticles from a solid metallorganic molecular precursor [bis(salicylaldehydeato)cobal(II)]; [Co(sal)₂] has been achieved via two simple steps: firstly, the [Co(sal)₂] precursor was precipitated from the reaction of cobalt(II) acetate and salicylaldehyde; in propanol under nitrogen condition; then, cubic phase Co₃O₄ nanoparticles with the size of mostly 20–30 nm could be produced by thermal treatment of the [Co(sal)₂] in air at 500 °C for 5 h. The as-synthesized products were characterized by powder XRD, FT-IR, TEM and SEM. The results confirm that the resulting oxide was pure single-crystalline Co₃O₄ nanoparticles. The optical absorption spectrum indicates that the direct band gaps of Co₃O₄ nanoparticles are 1.53 and 2.02 eV. The optical property test indicates that the absorption peak of the nanoparticles shifts towards short wavelength, and the blue shift phenomenon might be ascribed to the quantum effect. The hysteresis loops of the obtained samples reveal the ferromagnetic behaviors the enhanced coercivity (H _c ) and decreased saturation magnetization (M _s ) in contrast to their respective bulk materials.     

One-pot synthesis of oxoisoindoline-1,2,3-triazole hybrid by a Ugi–click reaction

1,2,3-Triazole-3-oxoisoindoline-1-carboxamide system was successfully synthesized by using a combination of Ugi and click reactions. This two-step, one-pot synthesis was started by the reaction of 2-formyl benzoic acid, propargyl amine, and cyclohexyl isocyanide in ethanol. The resultant Ugi adduct underwent a copper-catalyzed click reaction, producing the desired products in good yields.     

Kinetic Aspects of Styrene Polymerization with an Acyloxyamine

The present paper evaluates largely unstudied kinetic aspects of styrene polymerization with a (relatively new) acyloxyamine over several temperature levels and contrasts these features with regular styrene polymerization and styrene polymerization with TEMPO. These comparisons show that the system behaves rather like regular thermal polymerization of styrene at temperatures between 120–180°C. However, at higher temperatures (> 180°C), acyloxyamine has an initiator-like contribution, giving the rate of polymerization an extra boost while decreasing molecular weights. This is further corroborated by mathematical modeling for both conversion and molecular weight averages.