A Light-Driven Constitutional Pump

Area of Science:

• Chemical Science
• Materials Science
• Supramolecular Chemistry

Background:

• Achieving high degrees of nonequilibrium in dynamic covalent chemistry is crucial for emulating energy-dissipative, biomimetic behaviors.
• Reversible covalent bond reorganization is limited by rapid thermal equilibration, hindering kinetic asymmetry amplification.

Purpose of the Study:

• To develop a strategy for reaching high degrees of nonequilibrium in dynamic covalent systems.
• To create a light-driven constitutional pump for biomimetic applications.

Main Methods:

• Embedding a unidirectional pathway onto a reversible dynamic covalent metathesis reaction using light.
• Designing molecules with conjugative coupling between a diarylethene photoswitch and a polar olefin moiety.
• Utilizing photonic gating to suppress reverse pathways and generate a photoisomer intermediate.

Main Results:

• The system reached high degrees of nonequilibrium under continuous irradiation.
• A light-driven constitutional pump was demonstrated, driving the reaction network toward a nonequilibrium steady state (NESS).
• Pronounced constitutional selection was observed, with full reversibility upon light removal.

Conclusions:

• This work establishes a new strategy for highly nonequilibrium dynamic covalent systems.
• The findings lay the groundwork for developing life-like nonequilibrium matter.
• The molecular design enables photonic control over dynamic covalent reactions.