Isothermal titration calorimetry (ITC) experiments were performed for investigation of binary mixtures comprised of the Brønsted superbase DBN with hydrogen ethanoate (AcOH). The heat of mixing (HE) profile was recorded at (343.15 ± 0.1) K and fitted with a 5-parameter Redlich-Kister (RK) polynomial. RK fit parameters were subsequently used to quantify partial molar heats of mixing, xiHiE, for each component i. ITC-based complexometric titration data for the binary mixtures were recorded separately in methyl isobutyl ketone (mibk) and dodecane, to investigate the energetics of non-random clustering phenomena. Variable temperature 1H-NMR in combination with ATR-FTIR spectroscopic analyses were employed in parallel for elucidation and verification of liquid state ion speciation. These investigations reveal a strongly non-ideal system, and indicate “superbase” character of DBN is preserved for specific compositions where stoichiometric ionic liquids (ILs) form. Available ion speciation has been found to include [DBN-H]+, [AcO]− as well as μ2-hydrogen-bridged, hydrogen-bonded homoassociate anions, of the type [H(OAc)2]−, with double liquid salt formation characterising various compositions based on spectroscopic determinations.
- Complexometric titration
- Double liquid salt
- Heat of mixing
- Ionic liquids
- Isothermal titration calorimetry