Abstract: | Abstract The stability constants of several alkali metal ion complexes with the macrotetrolides were determined polarographically in acetonitrile. For any single alkali metal ion the stability constant increased in the order nonactin < monactin < dinactin < trinactin. Their values are larger than those found in methanol. The Stoke's radii estimated from the limiting diffusion currents of the complexes increase with increasing crystallographic radius of the cation. The increasing strain on the ligand causes a decrease of stability constant for Rb+ and Cs+. |