Imidazolium-Based Ionic Liquids. 1-Methyl Imidazolium Nitrate: Thermochemical Measurements and Ab Initio Calculations

Abstract

In this work data of the molar enthalpies of formation of the ionic liquid 1-methylimidazolium nitrate [H-MIM][NO3] was measured by means of combustion calorimetry. The molar enthalpy of fusion of [H-MIM][NO3] was measured using DSC. Experiments to vaporize the ionic liquid into vacuum or nitrogen stream in order to obtain vaporization enthalpy have been performed. Ab initio calculations of the enthalpy of formation in the gaseous phase have been performed for the ionic species using the G3MP2 theory. The combination of traditional combustion calorimertry with modern high-level ab initio calculations allow the determination of the molar enthalpy of vaporization of the ionic liquid under study. The ab initio calculations indicate that [H-MIM][NO3] is most probably separated into the neutral species methyl-imidazole and HNO3 in the gaseous phase at conditions of the vaporization experiments.

Imidazolium Ionic Liquids: An Environment-Friendly Medium for Various Applications

“…Many reviews had shown the importance of IL such as in supercritical fluid applications by Seda Keskin et al [54]. Measurements of thermochemical properties of imidazolium-based ionic liquid (ILs) carried out has been reported [55]. Tamar L. Greaves et al [56] explained the properties and applications of protic ILs.…”

Interactions and Transitions in Imidazolium Cation Based Ionic Liquids

“…drastically. [13][14] For instance, density of IL decreases as the length of the alkyl chain on the cation increases up to a certain length. For a given cation, the density increases as the molecular weight of the anion increases.…”

Experimental determination of enthalpy of 1-butyl-3-methylimidazolium iodide synthesis and prediction of enthalpies of formation for imidazolium ionic liquids

“…Calorimetric determination of the enthalpies of vaporization was reported in one work [3]. However, noncalorimetric techniques for determination of D g l H were used more often (for example, [4][5][6][7]). A review of the thermodynamics of IL vaporization has been recently published [8].…”

“…The enthalpies of formation have been obtained from the experimental data only for five ILs (table 1). The measurements were made either in combustion calorimeters [7,[26][27][28] or in a reaction calorimeter [10]. …”