Аннотация:Calorimetry was used to study the formation of the complexes: acetylbenzo-12-crown-4, acetylbenzo-15-crown-5 (AB15C5) and benzoylbenzo-15-crown-5 with alkali metal and NH4 thiocyanates at 298 K. Equil. consts. of (1:1 and 1:2) complexes and heats and entropies of formation were detd. The Na+ cation forms only the 1:1 complex with AB15C5. The Ca2+ cation forms only 1:1 complexes.