Synthesis and Potentiometric Selectivity Study of 14-Cyclic Dioxadiamides

Abstract

Three compounds of a new class of ionophores, 14-cyclic dioxadiamides, were synthesized and tested for potentiometric selectivity for lithium ion in poly(vinyl chloride) membrane electrodes. Four plasticizers were studied and the addition of trioctylphosphine oxide (TOPO) was considered. One ionophore exhibited a sodium/lithium selectivity, K^pot_{Li, Na}, by the matched potential method, of 0.012 in the presence of 1% TOPO, using o-nitrophenylphenyl ether as plasticizer. Selectivities are reported for sodium, potassium, ammonium, barium and calcium ions with respect to lithium ions.