Sorption/desorption study of strontium on Ain Oussera soils around the Es-Salam reactor facility

Four types of undisturbed soils around the Es-Salam reactor (Algeria) were used to evaluate the sorption behavior of strontium. The batch study was carried out under different experimental conditions. The kinetics were well fited by pseudosecond order model. Soils’s activation energies were 12.37, 14.76, 15.5 and 16.17 kJ mol⁻¹, corresponding to ion-exchange-type sorption. Sorption was exothermic (ΔH° < 0), spontaneous (ΔG° < 0) and favorable at low temperature. Competing cations, particularly Ca²⁺ reduce the Sr adsorption. Desorption reaction showed a higher value of Sr in the easily extractible phase indicating a relative availability of the element.

     

ortho-Lithium/magnesium carboxylate-driven aromatic nucleophilic substitution reactions on unprotected naphthoic acids

Substitution of an ortho-fluoro or methoxy group in 1- and 2-naphthoic acids furnishing substituted naphthoic acids occurs in good to excellent yields upon reaction with alkyl/vinyl/aryl organolithium and Grignard reagents, in the absence of a metal catalyst without the need to protect the carboxyl (CO(2)H) group. This novel nucleophilic aromatic substitution is presumed to proceed via a precoordination of the organometallic with the substrate, followed by an addition/elimination.