Stability of valinomycin-ammonium complex in nitrobenzene saturated with water

From the extraction experiments and gamma-activity measurements, the extrac tion constant corresponding to the equilibrium NH4+(aq) + NaL+ (nb) reversi ble arrow NH4L+ (nb) + Na+(aq) in the two-phase water-nitrobenzene system ( L = valinomycin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated in the form logK(ex)(NH4+, NaL+) = 3.1. Further, the stability constant of the valinomycin-ammonium complex in nitrobenzene saturated with water was calculated. log beta(nb)(NH4L+) = 8.5 Finally, the stability constants of c omplexes of some univalent cations with valinomycin were summarized and dis cussed.