Activity Coefficients at Infinite Dilution for Organic Solutes Dissolved in Three 1-Alkyl-1-methylpyrrolidinium Bis(trifluoromethylsulfonyl)imide Ionic Liquids Bearing Short Linear Alkyl Side Chains of Three to Five Carbons

Abstract

In this work, we report the infinite dilution activity coefficients (γ 1,2 ∞ ) of 39 to 43 diverse organic solutes dissolved in three 1-alkyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquids (IL) homologues bearing propyl, butyl, and pentyl n-alkyl side chains, respectively, as determined by inverse gas chromatography at temperatures from 323 K to 343 K. The organic solutes include various (cyclo)alkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, ethers, nitroalkanes, and ketones. The measured retention data were further transformed to gas-to-IL and water-to-IL partition coefficients using established thermodynamic approaches based upon the corresponding gas-to-water partition coefficients of the test solutes. Both sets of partition coefficients were interpreted with a modified form of the basic Abraham general solvation parameter model. The mathematical correlations obtained by regression analysis backcalculated the observed gas-to-IL and water-to-IL partition coefficient data to within average standard deviations of 0.104 and 0.136 log units, respectively.

Abraham model correlations for describing solute transfer into 2-butoxyethanol from both water and the gas phase at 298K

“…The model that we have been using in our studies has been the Abraham solvation parameter model [2,[21][22][23][24][25][26], which allows one to describe solute transfer between two condensed phases (a biphasic aqueous-organic or organic-organic system) or solute transfer to a condensed phase from the vapor phase. During the past five years we have published Abraham model correlations for 11 additional organic solvents (e.g., diisopropyl ether [27], tributyl phosphate [28], 2-hexadecene [29,30], 1,9-decadiene [29,30], sulfolane [31], benzonitrile [32], ethylbenzene [33], o-xylene [34], m-xylene [34], p-xylene [34], 2-ethoxyethanol [35], and propylene glycol [36]) and several ionic liquids [37][38][39][40][41][42][43][44][45][46][47], as well as updating our existing correlations for hexane [48], heptane [48], octane [48], decane [48], isooctane [49], toluene [33], tetrahydrofuran [50], and 1,4-dioxane [50].…”

Activity coefficients at infinite dilution for organic solutes dissolved in two 1-alkylquinuclidinium bis(trifluoromethylsulfonyl)imides bearing alkyl side chains of six and eight carbons

“…Our contributions in the area of IL research have been to publish experimental physical property measurements and thermodynamic data for both neat ILs [1][2][3] and for solutes dissolved in IL solvents [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. The latter measurements have led to the development of IL-specific Abraham model correlations [4][5][6][7][8][9][10][11][12][22][23][24]:…”

“…The latter measurements have led to the development of IL-specific Abraham model correlations [4][5][6][7][8][9][10][11][12][22][23][24]:…”

“…In Eqs. (5) and (6), n i denotes the number of times that the given fragment group appears in the cation and the summations extend over all fragment groups. Predictions based on Eqs.…”

Infinite Dilution Activity Coefficients of Solutes Dissolved in Two Trihexyl(tetradecyl)phosphonium Ionic Liquids

“…We have furthered these efforts by measuring the infinite dilution activity coefficients (γ i ∞ ) and gas-to-IL partition coefficients (K L ) of organic solutes dissolved in a host of ILs: 1-propyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 6 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 6 1-pentyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 6 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 7 1-octyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, diethylphosphate, 12 trihexyl(tetradecyl)phosphonium bis-(trifluoromethylsulfonyl)imide, 13 1-butyl-3-methylimidazolium tetrafluoroborate, 14 1-hexadecyl-3-methylimidazolium tetrafluoroborate, 15 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 15 1-butyl-3-methylimidazolium hexafluorophosphate, 15 1-butyl-3-methylimidazolium octylsulfate, 16 and 1-ethyl-3-methylimidazolium tosylate. 16 Results of this suite of experimental measurements were used to develop IL-specific Abraham model correlations for describing the logarithm of gasto-IL partition coefficients (log K L ) and the logarithm of waterto-IL partition coefficients (log P) of solutes dissolved in the given anhydrous IL solvent, 6−14 to determine cation-specific and anion-specific Abraham model equation coefficients, [6][7][8][9][10][11]13 and to calculate numerical fragment values for a group contribution version of the Abraham model. 17,18 This latter method contains provisions for estimating log K L and log P as a function of temperature.…”