The work focuses on the thermodynamics of controlling molecular photoswitches, a fundamental challenge for the stabilization of high-energy metastable states. Inspired by Maxwell's demon-like systems, researchers have employed hydrogen bonds as a molecular-level selector to modulate the thermal backconversion of quadricyclane (QC) to norbornadiene (NBD).
By strategically incorporating hydrogen-bond donors and acceptors, it has been shown that these interactions form a water "bridge" that restricts rotational degrees of freedom. This bridge significantly elevates the kinetic barrier and redirects isomerization along an alternative reaction coordinate. In this manner, the hydrogen-bonding system selectively regulates the thermal backconversion dynamics, achieving directional control over isomerization kinetics and extending the thermal half-life by up to 5000-fold.
This research illustrates how hydrogen bonds can facilitate precise control over backconversion dynamics and molecular thermal stability in photoswitches. The study is titled "Orchestrating photoswitch thermal backconversion using hydrogen bonds to reshape energy landscapes" and has been published in Nature Communications.
