Dual photoisomerization mechanism of azobenzene embedded in a lipid membrane

J Mater Chem B. 2023 Mar 15;11(11):2518-2529. doi: 10.1039/d2tb02767d.

Abstract

The photoisomerization of chromophores embedded in biological environments is of high importance for biomedical applications, but it is still challenging to define the photoisomerization mechanism both experimentally and computationally. We present here a computational study of the azobenzene molecule embedded in a DPPC lipid membrane, and assess the photoisomerization mechanism by means of the quantum mechanics/molecular mechanics surface hopping (QM/MM-SH) method. We observe that while the trans-to-cis isomerization is a slow process governed by a torsional mechanism due to the strong interaction with the environment, the cis-to-trans mechanism is completed in sub-ps time scale and is governed by a pedal-like mechanism in which both weaker interactions with the environment and a different geometry of the potential energy surface play a key role.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azo Compounds*
  • Lipids
  • Molecular Dynamics Simulation*
  • Quantum Theory

Substances

  • azobenzene
  • Azo Compounds
  • Lipids