Voltammetric characterization of selective potassium ion transfer across micro-water/1,2-dichloroethane interface facilitated by a novel calix[4]arene derivative

In this study, transfer reactions of alkali and alkaline-earth metal ions across a micro-water/1,2-dichloroethane (1,2-DCE) interface facilitated by a novel calix[4]arene derivative, 5,11,17,23-tetra-tert-butyl-25,27-bis(2′amino-methylpyridine)-26,28-dihydroxy calix[4]arene (APHC4), were investigated by cyclic and differential pulse voltammetry techniques. Well-defined voltammetric behavior was obtained only for K+ ion among the used metal ions. The electrochemical data were used to determine the stoichiometry and the appropriate association constant of the occurring complex between K+ ion and APHC4  . The obtained steady-state voltammograms indicated that the facilitated transfer process occurs with a TIC/TID mechanism according to 1:1 stoichiometry. The logarithm of the association constant (log β10) of K(APHC4)+ complex in the DCE phase was calculated to be 6.32. Also, the availability of the facilitated transfer for the design of an amperometric screening sensor for K+ ion was evaluated in the range of 50–500 μmol dm−3.

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► In this study, we investigate transfer reactions of alkali and alkaline-earth metal ions across a micro-water/1,2-dichloroethane interface facilitated by a novel calix[4]arene derivative (APHC4).
► Electrochemical data show that the facilitated transfer process of K+ ion occurs with a TIC/TID mechanism according to 1:1 stoichiometry.
► APHC4 exhibits good selectivity towards K+ ion among alkali and alkaline-earth metal ions.
► APHC4 can be a useful ionophore to fabricate ion-selective amperometric sensor.