Complexation of the Silver Cation with Dibenzo-30-crown-10: Extraction and DFT Study

From extraction experiments and gamma-activity measurements, the exchange extraction constant corresponding to the equilibrium Ag+(aq) + 1 center dot Cs+(nb) double left right arrow 1 center dot Ag+ (nb) + Cs+(aq) taking place in the two-phase water-nitrobenzene system (1 = dibenzo-30-crown-10; aq = aqueous phase, nb = nitrobenzene phase) was determined as log K-ex (Ag+, 1 center dot Cs+) = -1.7 +/- 0.1. Further, the stability constant of the complex 1 center dot Ag+ in nitrobenzene saturated with water was calculated for a temperature of 25 degrees C: log beta(nb) (1 center dot Ag+) = 6.0 +/- 0.2. Finally, by using quantum mechanical DFT calculations, the most probable structure of the resulting complex 1 center dot Ag+ was solved.