SYNTHESIS AND APPLICATION OF CROWN ETHERS

Mono- and bis-benzo-15-crown-5-ether derivatives have been synthesized and determined their potentiometric K+ selectivity factors. Of bis-crown ether urethanes highly selective Iigands were found some of which was used as active ingredient in potassium selective membrane electrode. Sugar based crown ethers, aza-crowns and cryptands were also prepared and applied as chiral catalyst in enantioselective reactions

Bis-crown ether derivatives as ionophores for potassium selective electrodes

The correlation between the chemical structure and potentiometric ion-selectivity of a new group of biscrown ether-derivatives has been studied in detail. It was concluded that with bis-benzo-15-crown-5 derivatives with a urethane linkage, NO 2 -substitution on both benzene rings is of utmost importance with respect to potentiometric performance. Hints have been given for the interpretation of the selectivity increasing effect of the NO 2 -substituent. The performance characteristics of the new ligand based electrodes were compared with those of the existing potassium selective sensors. © 1985 Springer-Verlag