Voltammetric Investigation of Host–Guest Systems in the Absence of a Supporting Electrolyte

Abstract

In the classic voltammetric approach to host--guest systems the investigations are carried out in excess of a supporting electrolyte, i.e., an inactive ionic salt. This approach ensures high electric conductivity of solution and ion migration is avoided. However, the presence of supporting electrolyte may introduce competitive equilibria and change activity coefficients, influencing the equilibrium constants using ultramicroelectrodes. Host–guest systems can be studied without addition of supporting electrolyte. Under such conditions, the interpretation of experimental results requires a theoretical description that accounts for migrational transport. Such a description is presented in this paper which also shows that migrational effects are so small that they can be neglected for some systems.