Natural Environment Monitoring 2011, No 12, 125-131
COMPLEXATION CHARACTERISTICS OF MEMBRANE-ACTIVE CROWN-ETHERS
Unida Sharafutdinova, Uktam Toyirov, Bachtior Salakhutdinov,
Anisa Tashmukhamedova, Ulugbek Mirkhodjaev
Summary
Crown ethers are the large class of membrane-active organic compounds which are intensively studied due to their complexon, ionophoric and channel forming activity. The present study describes the investigations of the possible interactions between sulfo-derivatives of DB18C6 with ions of K+, Na+, Ca2+ in water and ethanol solutions using conductance-measuring method. The analysis of thermodynamic characteristics of interaction, particularly free Gibbs energy (G) alteration, shows that the process of interaction of crown-ethers and uni- and bivalent ions is held spontaneously. In this case the interaction is supposed to proceed due to forming ion bounds between ions of dissociated salt and charged regions of crown-ethers. The obtained results for the sulfo-derivatives of DB18C6 show no ability to form stable interactions with ions of uni- and bivalent metals neither in water nor in ethanol solutions. It allows us to make a conclusion about non-inophoric nature of investigated compounds and proves the idea of their ability to change membrane permeability by forming ion-transporting structures.
