Chapter 5 - Physiochemical Properties of Aromatic Sulfur and Nitrogen Compounds with Imidazolium-Based Ionic Liquids

Abstract

The present chapter discussed the physiochemical properties of the hydrodesulphurization and hydrodenitrification inhibiting compounds with Ionic Liquids. Experimental density, surface tension and refractive index data will be discussed for the following systems with IL namely pyridine, pyrrole, quinoline, indoline, thiophene and water over the entire mole fraction of ILs at ambient conditions. Further from experimental density values, coefficient of thermal expansivity and excess molar volume are also reported. It was found that the heteroaromatic nitrogen/sulphur compounds and water are completely miscible in the ILs. The surface tension values were found to increase while the refractive index decreases with increasing mole fraction of ILs. On the other side non-aromatic molecule such as water showed mobility of ions on mixing resulting in lower surface tension. The experimental values of surface tension increased in the order: thiophene > pyridine > pyrrole > indoline > quinoline and for refractive index: quinoline > indoline > pyrrole > pyridine > thiophene > water. It was found that the composition of ILs has a greater influence than temperature in deciding the densities, surface, optical and thermodynamic properties for nitrogen and sulphur heterocycle.