TY - JOUR
T1 - Heat of mixing profile, complexation curve and spectroscopic investigation of binary mixtures containing bicyclic Brønsted superbase DBN with hydrogen ethanoate
AU - Driver, Gordon W.
AU - Sprakel, Lisette J.M.
AU - Kilpeläinen, Ilkka
AU - Schuur, Boelo
N1 - Funding Information:
GWD and IK acknowledge The Bio-based Industries Joint Undertaking (BBI-ju) project GRETE ( www.greteproject.eu), and LMJS and BS the Institute for Sustainable Process Technology (ISPT), for funding. Jussi Helminen (UH) is thanked for discussions regarding superbase hydrolysis and Sami Heikkinen (UH) for discussions regarding aspects of the NMR analysis.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/10
Y1 - 2021/10
N2 - 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.
AB - 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.
KW - Complexometric titration
KW - Double liquid salt
KW - Heat of mixing
KW - Ionic liquids
KW - Isothermal titration calorimetry
KW - Superbase
UR - http://www.scopus.com/inward/record.url?scp=85107396794&partnerID=8YFLogxK
U2 - 10.1016/j.jct.2021.106516
DO - 10.1016/j.jct.2021.106516
M3 - Article
AN - SCOPUS:85107396794
SN - 0021-9614
VL - 161
JO - The Journal of chemical thermodynamics
JF - The Journal of chemical thermodynamics
M1 - 106516
ER -