Using a dropping funnel, acid was added dropwise to a round bottomed
flask containing the corresponding amine, magnetically stirred, and
chilled to 0 °C using an ice bath. IL water content was reduced
to below 20 wt % by rotary evaporation and measured using a V20 Volumetric
Karl Fischer Titrator (Mettler-Toledo). Acid–base ratios of
[HSO4]− ILs were determined by titration
by 0.1 M NaOH, using a G20S Compact Titrator (Mettler-Toledo), standardized
using potassium hydrogen phthalate purchased from Sigma-Aldrich. Acid–base
ratios of [HCOO]−, [Cl]−, and
[OAc]− ILs were determined through calibration curves
of acid–base ratio vs pH for dilute solutions (0.5 wt %). 1H-NMR and 13C-NMR spectra were recorded on a Bruker
400 MHz spectrometer (Supporting Information ).
flask containing the corresponding amine, magnetically stirred, and
chilled to 0 °C using an ice bath. IL water content was reduced
to below 20 wt % by rotary evaporation and measured using a V20 Volumetric
Karl Fischer Titrator (Mettler-Toledo). Acid–base ratios of
[HSO4]− ILs were determined by titration
by 0.1 M NaOH, using a G20S Compact Titrator (Mettler-Toledo), standardized
using potassium hydrogen phthalate purchased from Sigma-Aldrich. Acid–base
ratios of [HCOO]−, [Cl]−, and
[OAc]− ILs were determined through calibration curves
of acid–base ratio vs pH for dilute solutions (0.5 wt %). 1H-NMR and 13C-NMR spectra were recorded on a Bruker
400 MHz spectrometer (