Thermodynamic properties of infinitely diluted solutions of organic solutes in in silico designed task-specific ionic liquid

Abstract

New experimental infinite dilution activity coefficients (IDACs) of 45 different molecular solutes (alkanes, cycloalkanes, alkenes, alkynes, aromatics, alcohols, ethers, ketones, thiophene, acetonitrile, pyridine and 1-nitropropane) in the novel ionic liquid 1-(3-cyanopropyl)-1-methyl pyrrolidinium thiocyanate are presented. The considered IL has been in silico designed in our previous work by using empirical group contribution method for IDAC calculation. The experimental results shown in this paper are discussed in terms of the strength and the chemical nature of mutual interactions between the IL and the molecular solutes. An effect of nitrile group is elucidated by means of comparison of the measured data with those reported in the literature for non-functionalized counterpart of the studied IL. Furthermore, an impact of the studied “task-specific” cation on the infinite dilution selectivity in thiophene/n-octane separation problem is highlighted. The entire data set presented herein is analyzed using linear solvation-energy relationship (LSER), regular solution theory and conductor-like screening model for real solvents (COSMO-RS).