Solvent extraction of barium into nitrobenzene by using ammonium dicarbollylcobaltate in the presence of 15-crown-5

Extraction of microamounts of barium by a nitrobenzene solution of ammonium dicarbollylcobaltate (NH₄⁺B^-) in the presence of 15-crown-5(15C5,L) has been investigated. The equilibrium data have been explained assuming that the complexes NH₄L⁺, NH₄L₂⁺ and BaL₂²⁺ are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.