Solvatochromic parameters for binary mixtures of an ionic liquid with various protic molecular solvents

摘要

Solvatochromic parameters(E_T~N,normalized polarity parameter;pi*,dipolarity/polarizability;beta,hydrogen-bond acceptor basicity;alpha,hydrogen-bond donor acidity)have been determined for binary mixtures of pro-pan-2-ol,propan-1-ol,ethanol,methanol and water with recently synthesized ionic liquid(IL;2-hydroxyefhylam-monium formate)at 25 °C.In all solutions except aqueous solution,E_T~N values of the media increase abruptly with the ILs mole fraction and then increase gradually to the value of pure IL.A synergistic behavior is observed for the alpha parameter in all solutions.The behavior of pi* and beta are nearly ideal for all solutions except for solutions of methanol with the IL.The applicability of nearly ideal combined binary solvent/Redlich-Kister equation was proved for the correlation of various solvatochromic parameters with solvent composition.The correlation between the calculated and the experimental values of various parameters was in accordance with this model.Solute-solvent and solvent-solvent interactions were applied to interpret the results.