ABSTRACT
J. C. Lockhart considered the complexation kinetics of cations from Periodic Groups I–III interacting with a variety of ligands, including macrocyclic ligands. Izatt et al., focused on cation-macrocycle interactions in a comprehensive survey of the thermodynamic and kinetic data, including references up through 1984. This chapter presents understanding of reaction mechanisms of complexation and the nature of current debates over this subject. An attempt at correlating the dynamics of the macrocycle ligand to the mechanisms of complexation will be made with the limited data available. In the many cation-crown ether systems have examined so far by ultrasonic absorption methods in aqueous and nonaqueous media, the Eigen-Winkler reaction mechanism, adequately describes the kinetic data. The mechanism of complexation that was generally accepted in the 1970s is the one attributed to Chock. The effect of chains or tails attached to macrocycle rings on complexation reactions has been addressed for Na+ reacting with a monoazo 15-crown-5 (15C5)-tailed macrocycle in methanol.
