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

摘要

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 (k~0) were evaluated by analysis of the experimental voltammetric data. They increase in the following order: k_(Cs+)~0 < k_(Li+)~0 < k_(Rb+)~0 < K_(Na+)~0 < k_(K+)~0, which is in accordance with their association constants except Cs~+ and Li~+.