ENHANCED LI-SELECTIVE IONOPHORIC PROPERTIES OF DOUBLE ARMED DIAZA-12-CROWN-4 DERIVATIVES( ION)

A variety of double armed crown ethers were prepared in which amine, a mide, ester, nitrile and pyridine moieties were attached as cation-lig ating sidearms to diaza-12-crown-4 ring. FAB-MS arid Li-7/C-13/Na-23 N MR binding and liquid membrane transport studies revealed that most of them exhibited Li+ cation selectivity, though corresponding single ar med lariat ethers showed Naf cation selectivity. Among them, amine-arm ed diaza-12-crown-4 derivative offered the highest Li+ ion-selective i onophoric property. its transport efficiency and selectivity were part icularly superior to those of commercially available Li+ ion-selective ionophores. (C) 1997 Elsevier Science Ltd.