Interactions between tetra(trifluoromethylsulfonyl)-1,4,8,11-tetraazocyclotetradecane and perchlorate anion in propylene carbonate, nitromethane, acetonitrile, and tetrahydrofuran

Electrical conductance measurements are reported for lithium perchlorate and the anion receptor tetra(trifluoromethylsulfonyl)-1,4,8,11-tetraazocyclotetradecane (TTCD) in different aprotic solvents (propylene carbonate, nitromethane, acetonitrile, and tetrahydrofuran). The data have been analyzed by a suitable method based on the Lee-Wheaten theory on mixed electrolytes in order to obtain the true thermodynamic formation constants of macrocyclic-anion complexes and the ion pairs of both the uncomplexed (ClO4-) and complexed (TTCD-ClO4-) anions. The results show that the anion-ligand formation constants increase with decreasing dielectric constant and that the presence of the ligand increases the ionization of lithium perchlorate and enhances the transference number of lithium ion. These findings are of particular interest in view of the technological application of anion receptors in electrolyte solutions for lithium batteries.