Phase behavior of catalytic deactivated compounds and water with 1-ethyl-3-methylimidazolium acetate [EMIM][OAc] ionic liquid at T=298.15-323.15 K and p=1 bar

Density, surface tension and refractive index of the binary mixture of catalytic deactivated compounds with 1-ethyl-3-methylimidazolium acetate {[EMIM][OAc]} ionic liquid were measured at temperature of 298.15-323.15 K from which the derived thermodynamic properties including excess molar volume and deviation of surface tension and refractive index were calculated. The derived thermodynamic properties could be explained well by the interaction between similar and dissimilar aromatic structure of the molecules over the entire mole fraction of ILs. It was observed that all the catalytic deactivated compounds and water molecules have significant structural interaction with [EMIM][OAc] via CH center dot center dot center dot pi bond interaction, pi center dot center dot center dot pi stacking and n center dot center dot center dot pi interaction over the entire mole fraction of IL at T = 298.15 K. Further the composition of ionic liquid have significant influence on the interaction between dissimilar aromatic structure of molecules like pyridine, indoline and quinoline in liquid phaseas compared to temperature. The surface tension increases in the order of: hiophene > pyridine > quinoline > pyrrole > indoline > water; while the refractive index increases in the order: pyridine < water < pyrrole < thiophene < indoline < quinoline. The deviation of surface tension was found to be inversely proportional to the deviation of refractive index at T = 298.15 K. From these results it was concluded that the structure of the ionic liquids is very important for extraction processes on catalytic deactivated compounds, especially for pyridine, indoline and quinoline as compared to water molecules. (C) 2011 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.