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, NO2-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 NO2-substituent. The performance characteristics of the new ligand based electrodes were compared with those of the existing potassium selective sensors.