Kinetics of the protonation of macrocyclic amines in the presence of monovalent cations in aqueous solution

For macrocyclic bases such as: 1-aza-15-crown-5 (N15C5),1,4,10-trioxa-7,13- diazacyclopentadecan (21), 1,7,10,16-tetraoxa-4,13-diazacyclooctadecan (22) and 1, 4, 7, 13,16-pentaoxa-10,19-diazacycloheneicosane (23), the kinetics of deprotonation and protonation reactions in the presence of monovalent c ations was studied using the temperature jump technique. For the sake of co mparison, the measurements were also performed for 1,4-diazabicyclo[2,2,2]o ctane (DABCO) base, which does not form complexes with monovalent cations. The monovalent cations affect the temperature dependence of the kinetic par ameters of deprotonation. They also affect the activation parameters, which is shown by a distribution of DeltaH(not equal) and DeltaS(not equal) valu es, but do not influence the value of DeltaG(not equal).