Spectroscopically Visualizing the Evolution of Hydrogen-Bonding Interactions.

Area of Science:

• Physical Chemistry
• Chemical Physics
• Spectroscopy

Background:

• Understanding chemical bond variations is crucial for chemical processes.
• Visualizing the evolution of hydrogen bonds during proton transfer is experimentally challenging due to transient timescales.

Purpose of the Study:

• To precisely manipulate and visualize different hydrogen-bonding configurations during proton transfer.
• To explore the nature and evolution of hydrogen bonds in acid-base interaction complexes.

Main Methods:

• Subtly regulating proton-donating ability of zeolites or tungstophosphoric acid.
• Utilizing advanced two-dimensional (2D) heteronuclear correlation nuclear magnetic resonance (NMR) spectroscopy.
• Employing theoretical simulations to derive potential energy surfaces.

Main Results:

• Simultaneously monitored electronic properties of proton donors and acceptors via chemical shifts.
• Identified hydrogen bond types using parabolic 1H-13C NMR relationships and potential energy surfaces.
• Successfully visualized the evolution of hydrogen bonds in diverse acid-base complexes.

Conclusions:

• The study provides a new perspective on revealing the nature and evolution of hydrogen bonds.
• Confirms the superiority of 2D NMR techniques in distinguishing subtle differences in hydrogen-bonding configurations.
• Demonstrates precise manipulation of hydrogen-bonding configurations through controlled proton donation.