Liquid–Liquid Equilibrium of Cholinium-Derived Bistriflimide Ionic Liquids with Water and Octanol

Abstract

The liquid-liquid equilibria of mixtures of cholinum-based ionic liquids (N-alkyl-N,N-dimethylhydroxyethylammonium bis(trifluoromethane)sulfonylimide, [N(11n2OH)][Ntf(2)], n = 1, 2, 3, 4, and 5) plus water or 1-octanol were investigated at atmospheric pressure over the entire composition range. The experiments were conducted between 265 and 385 K using the cloud-point method. The systems exhibit phase diagrams consistent with the existence of upper critical solution temperatures. The solubility of [N(1 1 n 2OH)][Ntf(2)] in water is lower for cations with longer alkyl side chains (larger n values). The corresponding trend in the octanol mixtures is reversed. The ([N(1 1 1 2OH)][Ntf(2)] + water + octanol) ternary system shows triple liquid-liquid immiscibility at room temperature and atmospheric pressure. A combined analytic/synthetic method was used to estimate the corresponding phase diagram under those conditions. Auxiliary molecular dynamics simulation data were used to interpret the experimental results at a molecular level.

Assessing the activity coefficients of water in cholinium-based ionic liquids: Experimental measurements and COSMO-RS modeling

“…Cholinium chloride (also known as choline chloride, 2-hydroxyethyltrimethyl ammonium chloride or vitamin B4) is a cheap organic salt with high melting/degradation point (298-304 • C). Early works on the other organic solvents are still poorly characterized [32][33][34]. The thermodynamic and transport properties of ionic liquids and their mixtures with water are crucial to understand the molecular interactions between the components of the mixture and also for designing applications such as absorptive cooling, gas dehydration, extractive distillation, and liquid-liquid extraction, among others.…”

Development of Ionic Liquid‐Water‐Based Thermomorphic Solvent (TMS)‐Systems for Biocatalytic Reactions

“…The liquid–liquid‐phase equilibria of cholinium bistriflate amide 1 ([N 1112 (OH)][NTf 2 ]) including derivatives with longer alkyl chains with water are relatively well characterized. These ILs are considered as biocompatible, but such systems exhibit a relatively high cloud point temperature of at least 70 °C, depending on the IL and the composition of the mixture . For this study, this value was lowered by adding a set of phase mediators, whereas 1,4‐dioxane was chosen as the optimal additive (Figure A).…”

Probing Ionic Liquid Aqueous Solutions Using Temperature of Maximum Density Isotope Effects

“…discussion section), the table also includes molar volume values of the pure ionic liquids, estimated at 298K using the predictive method developed by Rebelo et al . [ 7 , 8 ].…”