A calorimetric titration study of uni-and bivalent metal ion interaction with several thia derivatives of 9-crown-3, 12-crown-4, 15-crown-5, 18-crown-6, 24-crown-8, and with several oxathiapentadecanes in water or water-methanol solvents at 25 °C

Abstract

The interaction of several sulfur derivatives of crown-3, crown-4, crown-5, crown-6, crown-8, and three oxathiapentadecanes with Ag +, Hg 2+, Tl +, and Pb 2+ in water or water-methanol solvents has been studied by a calorimetric titration procedure. The partial substitution of sulfur for oxygen in the crown-5 and crown-6 ligands results in little change in the affinity of the ligand for Tl + and Pb 2+, but greatly increased affinity for Ag + and Hg 2+. Values of log K, ΔH, and TΔS are reported where their determination was possible. Cation-ligand stoichiometries of 1:2 were found for Ag + and Hg 2+ complexes of many of the cyclic thia ethers. Only 1:1 complexes were found for Tl + and Pb 2+.