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

Abstract

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) ([Formula: see text]), 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.