Systematic Investigation of Alkali Metal Ion Transfer Across the Micro- and Nano-Water/1,2-Dichloroethane Interfaces Facilitated by Dibenzo-18-crown-6

Abstract

Facilitated alkali metal ion (M+= Li+, Na+, K+, Rb+, and Cs+) transfers across the micro- and nano-water/1,2-dichloroethane (W/DCE) interfaces supported at the tips of micro- and nanopipets by dibenzo-18-crown-6 (DB18C6) have been investigated systematically using cyclic voltammetry. The theory developed by Matsuda et al. was applied to estimate the association constants of DB18C6 and M+ in the DCE phase based on the experimental voltammetric results. The kinetic measurements for alkali metal ion transfer across the W/DCE interface facilitated by DB18C6 were conducted using nanopipets or submicropipets, and the standard rate constants (k0) were evaluated by analysis of the experimental voltammetric data. They increase in the following order: < < < < , which is in accordance with their association constants except Cs+ and Li+.