Ion-Selectivity of Tetranactin

Abstract

The complex formation of tetranactin with Na, K, Rb, and Cs thiocyanates in methanol and acetone-d₆ was examined by infrared and ¹H-nuclear magnetic resonance spectra measurements. The equilibrium constants of complex formation were obtained from the analysis of the spectra and were compared with each other with respect to the kind of cation and solvent. The ion-selectivity of tetranactin was explained mainly by the difference among ionic species with respect to the changes of ionic solvation and tetranactin conformation due to complex formation.