Facilitated Ion Transfers at the Micro-Water/1,2-Dichloroethane Interface by Crown Ether Derivatives

The transfers of potassium ion (K+) facilitated by 3,3,6,6-tetrakis[p-(n-dodecyloxy)benzoyloxymethyl]dibenzo-18-crown-6 (L1) and of sodium ion (Na+) facilitated by 3,6-bis{3,4,5-tris[p-(n-dodecyloxy)benzyloxy]benzoyloxymethyl}benzo-15-crown-5 (L2) have been investigated at the micro-water/1.2-dichloroethane (micro-W/DCE) interface supported at the tip of a micropipette by cyclic voltammetry and chronoamperometry. The experimental results demonstrate that the mechanisms of both facilitated ion transfer (FIT) processes correspond to the transfer by an interfacial complexation (TIC) and the transfer by an interfacial dissociation (TID) processes. Some thermodynamic parameters, such as, stoichiometry, diffusion coefficient and the association constants are evaluated by cyclic voltammetry. Furthermore, the chronoamperometry has been employed to explore the roughness of the interface supported at the micropipette by analysis of the current-time curves based on the system of facilitated Na+ transfer by L2 at the water/DCE interface.