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 + Δδ) 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.