Synthetic Polyether Dicarboxylic Acids Exhibiting Lithium Ion-Selective Transport

Polyether dicarboxylic acid carriers with several alternate units of oxytrimethylene and oxy-o-phenylene groups have been synthesized. They exhibit lithium ion selectivity in the competitive cation transport among lithium, sodium, and potassium ions through liquid membranes. On the basis of the cation extraction and the spectroscopic behavior, it is proposed that these carriers form a coiled structure into which the lithium ion becomes selectively incorporated to exhibit lithium ion-selective transport.