Capillary electrophoretic study of solvent effects on complexation of dibenzo-18-crown-6 with potassium ions
Abstrakt
Affinity capillary electrophoresis was used for investigation of solvent effect on stability constant of model complex of dibenzo-18-crown-6 with potassium ion in mixed hydro-organic solvents at different water/methanol, water/ethanol and water/propan-2-ol ratios. The apparent stability constant was obtained by non-linear regression analysis of the dependency of effective electrophoretic mobility of the dibenzo-18-crown-6 on potassium ion concentration in the background electrolyte.
Prior to the regression analysis, the measured effective electrophoretic mobilities of the dibenzo-18-crown-6 were recalculated to the constant ionic strength. The obtained apparent stability constant of the complex was found to be strongly decreasing with increasing molar fraction of water in mixed solvents.