Extraction of microamounts of calcium and strontium into nitrobenzene using synergistic mixture of hydrogen dicarbollylcobaltate and 2,3-naphtho-15-crown-5

摘要

Extraction of microamounts of calcium and strontium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H~+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 HL~+, HL_2~+, CaL~(2+), CaL_2~(2+) and SrL_2~(2+) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. It has been found that in water saturated nitrobenzene the stability constant of the SrL_2~(2+) cationic complex species is substantially higher than that of the complex CaL_2~(2+).