Solvent extraction of microamounts of cesium into nitrobenzene using ammonium and thallium dicarbollylcobaltates in the presence of 2,3-naphtho-15-crown-5

Extraction of microamounts of cesium by a nitrobenzene solution of ammonium dicarbollylcobaltate (NH4B-) and thallium dicarbollylcobaltate (Tl+B-) in the presence of 2,3-naphtho-15-crown-5 (N15C5, L) has been investigated. The equilibrium data have been explained assuming that the complexes ML+ and ML2+ (M+ = NH4+; Tl+; Cs+) are present in the organic phase. The stability constants of the ML+ and ML2+ species (M+ NH4+; Tl+) in nitrobenzene saturated with water have been determined. It was found that the stability of the complex cations ML+ and ML2+ (M+ NH4+; Tl+; Cs+; L = N15C5) in the mentioned medium increases in the Cs+ < NH4+ < Tl+ order. (author)