Disequilibrating azobenzenes by visible-light sensitization under confinement.

Area of Science:

• Supramolecular Chemistry
• Photochemistry
• Organic Materials Science

Background:

• Azobenzene photoisomerization (E to Z) is crucial for molecular applications.
• Current methods often require limiting ultraviolet light.
• A need exists for visible-light-driven azobenzene isomerization.

Purpose of the Study:

• To develop a supramolecular method for E-to-Z azobenzene isomerization using visible light.
• To overcome the limitations of UV-only photoexcitation.
• To enable new applications of azobenzene photoisomerization.

Main Methods:

• Introduction of disequilibration by sensitization under confinement (DESC).
• Utilizing a macrocyclic host and a photosensitizer.
• Selective binding and sensitization of E-azobenzenes within the host.

Main Results:

• DESC successfully induces E-to-Z isomerization using visible light, including red light.
• The Z isomer is expelled from the host, allowing continuous conversion.
• Out-of-equilibrium photostationary states, inaccessible by direct excitation, are achieved.

Conclusions:

• DESC offers a versatile supramolecular strategy for visible-light-driven azobenzene isomerization.
• This approach broadens the applicability of azobenzene-based technologies.
• The method efficiently converts photon energy into chemical energy.