Effect of complexation on electrical conductivity in system consisting of an anion-radical salt and a crown ether

Various experimental methods have been used in a study of the effect of complexation on the electrical conductivity in systems consisting of an anion-radical salt of an alkali metal, a crown ether (CE), and a polar solvent. The electrical conductivity of solutions of M⁺TCQDM (TCQDM = tetracyanoquinodimethane) in the presence of the CE is determined by the ratio () of the radius of the CE cavity to that of the metal ion. The equilibrium constants of the processes taking place in these systems have been determined. It has been established that the electrical conductivity of the systems is determined by the following: a) electrostatic interaction (with = 0–0.8 and > 2); b) formation of complexes {M⁺...CE (with }- 1); c) formation of ternary associates {A...M⁺...CE (with }- 1.4). In the last case, the symmetry of the environment of the M⁺ ion is increased and the potential barrier to the transition of ions between the equilibrium positions is lowered, which is responsible for the observed increase in mobility of the ions in solution.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 22, No. 2, pp. 188–196, March–April, 1986.