Laura M. Sprunger

Characterization of room-temperature ionic liquids by the abraham model with cation-specific and anion-specific equation coefficients

Gas-to-RTIL (room-temperature ionic liquid) partition coefficients have been compiled for 592 different solute-RTIL combinations. These partition coefficients were converted into water-to-RTIL partition coefficients using the corresponding gas-to-water partition coefficients. Both sets of partition coefficients were analyzed using the Abraham solvation parameter model with cation-specific and anion-specific equation coefficients. The derived equations correlated the experimental gas-to-RTIL and water-to-RTIL partition coefficient data to within 0.10 and 0.14 log units, respectively. The 8 sets of calculated cation-specific equation coefficients and 4 sets of calculated anion-specific equation coefficients can be combined to yield expressions capable of predicting the partition coefficients of solutes in 32 different RTILs.

Linear Free Energy Relationship Correlation of the Distribution of Solutes between Water and Sodium Dodecyl Sulfate (SDS) Micelles and between Gas and SDS Micelles

Data have been assembled from the published literature on the water-to-micellar sodium dodecyl sulfate (SDS) partition coefficient data for more than 200 compounds and on the gas-to-micellar SDS partition coefficient data for more than 140 compounds. It is shown that an Abraham solvation equation with only five descriptors can be used to correlate the observed partition coefficient data to within a standard deviation of 0.22 log units. Micellar electrokinetic chromatographic (MEKC) retention factor data measured on a micellar SDS pseudostationary phase was also gathered from the literature. The water-to-micellar SDS partition coefficient and MEKC retention factor data were combined into a single database and correlated with the Abraham model. The derived correlation described the 486 experimental values to within a standard deviation of 0.15 log units. The micellar SDS system has been compared to various liquid phases in terms of solubility of gases and vapors and has been shown to be a very selective system-more so than room-temperature ionic liquids.

Linear free energy relationship (LFER) correlations for the solubilising characterisation of room temperature ionic liquids containing triethylsulphonium and 1-butyl-1-methylpyrrolidinium cations

Gas-to-room temperature ionic liquid (RTIL) partition coefficients have been compiled from the published literature for solutes dissolved in triethylsulphonium bis(trifluoromethylsulphonyl)imide, {[E3S]+[(Tf)2N]−}, and in 1-butyl-1-methylpyrrolidinium trifluoromethanesulphonate, {[BMPyr]+[Trif]−}. These partition coefficients were converted into water-to-RTIL partition coefficients using the corresponding gas-to-water partition coefficients. Both sets of partition coefficients were analysed using the Abraham model with cation-specific and anion-specific equation coefficients. Equation coefficients are reported for the triethylsulphonium and 1-butyl-1-methylpyrrolidinium cations. The calculated cation coefficients can be combined with our previously determined eight sets of anion-specific equation coefficients to yield expressions capable of predicting the partition coefficients of solutes in 16 different RTILs.

Computation methodology for determining Abraham solute descriptors from limited experimental data by combining Abraham model and Goss-modified Abraham model correlations

A new computation methodology is proposed for calculating the Abraham solute descriptors. The proposed method combines correlations based on both the Abraham model and the Goss-modified version of the Abraham model. The computation methodology is illustrated using published solubility and partition data for benzil in a wide range of organic solvent systems. Calculated solute descriptors back-calculate the observed experimental values to 0.119 log units. The proposed method of using both the Abraham model and the Goss-modified Abraham model correlations significantly increases the number of available equations that can be used in the solute descriptor determination.

LFER correlations for the solubilising characterisation of room temperature ionic liquids containing trifluoromethanesulfonate and trifluoroacetate anions

Gas-to-RTIL (room temperature ionic liquid) partition coefficients have been compiled from the published literature for solutes dissolved in 1-methyl-3-butylimidazolium trifluoromethylsulfonate, {[MBIm]+[Trif]−}, and in 1-methyl-3-ethylimidazolium trifluoroacetate, {[MEIm]+[F3Ac]−}. These partition coefficients were converted into water-to-RTIL partition coefficients using the corresponding gas-to-water partition coefficients. Both sets of partition coefficients were analysed using the Abraham model and Goss modified Abraham models with cation-specific and anion-specific equation coefficients. Equation coefficients are reported for the trifluoromethylsulfonate and trifluoroacetate anions. The calculated anion coefficients can be combined with our previously determined eight sets of cation-specific equation coefficients to yield expressions capable of predicting the partition coefficients of solutes in 16 different RTILs.

Characterisation of room temperature ionic liquid chromatographic stationary phases by combining experimental retention factor and partition coefficient data into a single model

Experimental gas-to-liquid partition coefficients, K, and chromatographic retention factors, k, have been compiled from the published literature for gases and organic solutes in 1-methyl-3-butylimidazolium bis(trifluoromethylsulfonyl)imide. In total, 102 experimental values were collected. It is shown that an Abraham solvation equation with five solute descriptors and one experimental data-type indicator can be used to correlate the combined log K and log k values. The derived correlation described the experimental data two within 0.1 log units. Training and test set analyses were used to validate the derived correlation model.

Linear free energy relationship correlations for the solubilising characterisation of room temperature ionic liquids containing 1-hexyloxymethyl-3-methylimidazolium and 1,3-dihexyloxymethylimidazolium cations

Gas-to-room temperature ionic liquid (RTIL) partition coefficients have been compiled from the published literature for solutes dissolved in 1-hexyloxymethyl-3-methylimidazolium bis(trifluoromethylsulphonyl)imide, {[HxomMIm]+[(Tf)2N]−}, and in 1,3-dihexyloxymethylimidazolium bis(trifluoromethylsulphonyl)imide, {[(Hxom)2Im]+[(Tf)2N]−}. These partition coefficients are converted into water-to-RTIL partition coefficients using the corresponding gas-to-water partition coefficients. Both sets of partition coefficients are analysed using the Abraham model with cation-specific and anion-specific equation coefficients. The equation coefficients are reported for the 1-hexyloxymethyl-3-methylimidazolium and 1,3-dihexyloxymethylimidazolium cations. The calculated cation coefficients can be combined with our previously determined nine sets of anion-specific equation coefficients to yield expressions capable of predicting the partition coefficients of solutes in 18 different RTILs.