Complexing ability of 2,8,14,20-tetrabenzol-sulfo-calix[4]resorcenarene in relation to Cs+, Рd2+, Се3+, Eu3+ ions in aqueous solution

Abstract

The stability constants of complexes formed in a result of interaction «host-guest» of water-soluble calix[4]resorcinarene with metal ions (Cs+, Pd2+, Ce3+, Eu3+) in ratio 1:1 and thermodynamic parameters of their formation were calculated. The dependence of the Gibbs energy change of formation of complexes on the atomic number of the element was constructed. It is shown that the value of stability constants depends on the degree of deprotonation of the rim of the calix[4]resorcinarene. It is found that the guest-cations — Ce3+ and Eu3+ are characterized by high charge density, whereby they form the complexes which are relatively strong, and more hydrated.