| Abstrakt: |
AbstractA complexation study concerning the interaction between Ag+, NH+4, Li+, Na+, K+, Rb+, Cs+, Mg2+, Ca2+, Sr2+, and Ba2+ions with the crown ethers 15-crown-5, benzo-15-crown-5, 18-crown-6, benzo-18-crown-6 and the cryptands (211), (221) and (222) in N,N-dimethylform-amide solution has been carried out at 25°C. The stability constants of the resulting complexes were determined by means of conductometric, calorimetric and potentiometric titrations. The calorimetric titration was also used to determine the reaction enthalpy. It is found that the silver ion forms with cryptands the most stable complexes. Among the investigated alkali and alkaline earth cryptates the [Li+C211], [Ca2+C211], [Na+C221], [Srf+C221], [K+C222], and [Ba2+C222] cryptates show the highest stability constants. K+and Ba2+form with the examined crown ethers the most stable complexes among the alkali and alkaline earth complexes; 15-crown-5 and benzo-15-crown-5 form 2:1 complexes with some of the cations. |
