The potentiometric determination of stability constants of macrocyclic ethers using linear regression techniques

Abstract

The stability constants of various stoichiometries of NaCl complexes of the macrocyclic ethers of 15-crown-5, benzo-15-crown-5, 18-crown-6 and benzo-18-crown-6 were measured by maintaining identical initial ion-ligand concentrations [A0+]=[Lo] and using the expression of the stability constant βi of a complex formation, 1/βi[Lo]n+m−1=(1−nP′)n(1−mP′)m/P′ where P′=PAL/[1+PAL(m−1)]. The potentiometric measurements were carried out in water with a glass membrane electrode in a computer-ion meter system.