Binding Energy as Driving Force for Controllable Reconstruction of Hydrogen Bonds with Molecular Scissors

Hydrogen bonds are one of the most
important directional intermolecular
interactions and play key roles in chemical and biochemical systems,
but there is still a lack of prediction and understanding of their
control. Herein, hydrogen-binding energy (EHB) acted as a driving force for controllably reconstructing hydrogen
bonds with molecular scissors. We related hydrogen-binding energies
of the donor–acceptor couple (EHB,2) and the donor itself (EHB,1) and ΔG based on ΔG = a1EHB,1 + a2EHB,2 + a3. When EHB,1 and EHB,2 satisfy the condition ΔG < 0, the acceptor is predicted as molecular scissors with sufficient
reconstruction capacity in breaking the initial hydrogen bonds and
forming new ones. Remarkably, we developed an experimental method
to determine the EHB values by a linear
equation as a function of chemical shifts (δ) (ln⁡δ+σδ=−EHBRT+A), which
is innovational since in the former
research EHB can only be deduced from
empirical formulas and DFT calculation. On that basis, the hydrogen
bonds of α-cellulose were broken and re-formed in molecular
scissors-consisting deep eutectic solvents, leading to the white powder
transforming into a hydrogel and colorless and transparent thin film
materials with distinct crystalline structure, surface flatness, and
morphology.