1-Octanol/Water Partition Coefficients of 1-Alkyl-3-methylimidazolium Chloride~+

摘要

The solubilities of 1-alkyl-3-methylimidazolium chloride [C_nmim][Cl] where n=4,8,10,and 12,in 1-octanol and water have been measured by a dynamic method in the temperature range from 270to 370 k the solubility data was used to calculate the 1-octanol/water partition coefficients as a funcion and enthalpies of solid-solid phase transitions were determined by differentaila scanning calorimetry DSC The solubility of [C_nmin][Cl] where n=10 or 12 in 1-octanol si comparable and higher than that of [C_4mim][Cl] in 1-octanol.Liquid 1-n-octyl-3-methylimidazolium chloride [C-8mim][Cl] is not miscible with 1-octanol and water consequently the liquid-liquid equilibrium LLE was measured in this system The differences between the solubilities in water for n=4 and 12 are shown only in a and gammasolid crystalline phases Additionally the immiccibility region was observed for hte higher concentration of [C_10min][Cl] in water Teh intermolecular solute-solvent interactin of 1-buty1-3-methylimidzolium chloride with water is highere than for other 1-alkyl-3-methylimidazoilum chlorides The data was correlated by meand of the UNIQUAC ASM and two modified NRTL equatins utiliizing parameters derived form the solid-liquid equilibrium SLE The root-mean-square deviations of the solubility temperatures for all calaculated data are from 1.8to 7 K and depend on the particular euatin used Int he calculations the existence of two solid-solid first-order phade transitios in [C_12mimm][Cl] has also been taken into considerdatin Experimental partition coefficients (logP) are negative at three temperature this is evidence fro the spossible use of these ionic liluids as green solvents.