THE POTENTIOMETRIC DETERMINATION OF STABILITY-CONSTANTS OF MACROCYCLIC ETHERS USING LINEAR-REGRESSION TECHNIQUES

The stability constants of various stoichiometries of NaCl complexes o f the macrocyclic ethers of 15-crown-5, benzo-15-crown-5, 18-crown-6 a nd benzo-18-crown-6 were measured by maintaining identical initial ion -ligand concentrations [A0+] = [L(o)] and using the expression of the stability constant beta(i) of a complex formation, 1/beta(i)[L(o)]n+m- 1 = (1 - nP')n(1 - mP')m/P' where P' = P(AL)/[1 + P(AL)(M - 1)]. The p otentiometric measurements were carried out in water with a glass memb rane electrode in a computer-ion meter system.