Voltammetric investigation of host-guest systems in the absence of a supporting electrolyte

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