Extraction of silver into nitrobenzene using cesium dicarbollylcobaltate in the presence of 18-crown-6

From several cesium distribution experiments with Cs-134 tracer, the exchan ge extraction constant corresponding to the equilibrium Ag+(aq)+CsL-(nb)rev ersible arrow AgL-(nb)+Cs+(aq) in the two-phase water-nitrobenzene system ( L = 18-crown-6; aq = aqueous phase, nb = nitrobenzene phase) was determined as log K-ex(Ag-,CsL+) = -0.6+/-0.1. Furthermore, the stability constant of the silver - 18-crown-6 complex in nitrobenzene saturated with water was e valuated for a temperature of 25 degreesC: log beta (nb)(AgL+) = 8.2+/-0.1. Finally, the individual extraction constant of the species AgL+ in the wat er-nitrobenzene system corresponding to the equilibrium AgL+(aq)reversible arrow AgL+(nb) was calculated: K-AgL(1)+ = -1.2+/-0.1.