Aromatic cation ionic liquids (ILs) based on alkylpyridiniums are shown to be good phenol extractants from model oils (hexane/toluene). ILs with hard basic anions are found to have best extraction efficiency consistent with tetraalkylammonium salts ([NR4]X). Key extraction interactions were analysed using small angle neutron diffraction. Trifluoromethanesulfonate ([OTf]- or triflate) anions provide the synergistic effects of reduced cation-phenol centre of mass (COM) distances and increased hydrogen bonding that are linked to the improved extraction efficiency. Increases in cation electron density (methyl-pyridinium ([Me-Py]+) vs methyl-picolinium ([Me-3-Pic]+)) also reduce cation-phenol COM interaction lengths consistent with small increases in extraction efficiency for the same ionic liquids.
- ionic liquids
- phenol extraction
- Neutron Scattering
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
Turner, A., Byrne, E., Pereira, T., & Holbrey, J. D. (2020). Enhanced Extraction of Phenol from Model Oils Using Ionic Liquids Elucidated with Neutron Diffraction. Physical Chemistry Chemical Physics (PCCP), 22(18), 10219-20226. https://doi.org/10.1039/D0CP01013H