Understanding and Measurement for the Binding Energy of Hydrogen bonds of Biomass-Derived Hydroxyl Compounds

Experimental measurement for the binding energy of hydrogen-bonds (HBs) has long been an attractive and challenging topic in chemistry and biochemistry. In the present study, the binding energy of OH···O HBs can be determined by ¹H NMR technique using a set of model biomass-derived hydroxyl compounds, including furfuryl alcohol, isosorbide, tetrahydrofurfuryl alcohol, and (S)-3-hydroxytetrahydrofuran. By performing concentration- and temperature-variation experiments, we put forward a modified Arrhenius-type equation, in which the compensated natural logarithm of the chemical shift (ln δ + Δ_δ) is linearly correlated with 1/T. HBs energies can be directly determined by the slope of the plot, and are substantiated by density functional theory (DFT) theoretical calculations. This study provides a reliable method to measure the binding energy of OH···O HBs in hydroxyl-containing biomass-derived feedstocks.