Controlling the Isomerization of Photoresponsive Molecules through a Limiting Tautomerization Strategy

J Phys Chem B. 2022 May 5;126(17):3347-3354. doi: 10.1021/acs.jpcb.2c02005. Epub 2022 Apr 26.

Abstract

Controlling the multistage photoresponsivity remains a challenge, in part, due to the spontaneous tautomerization between isomers. Herein, we present a strategy to access three independent states (linear, cyclic keto, and cyclic enolate) of crown ether (CE)-substituted donor-acceptor Stenhouse adducts (DASAs) by limiting the tautomerization of the closed isomers. The linear-cyclic keto isomerization is reversibly triggered by treatment with metal ions (Na+ or K+) and CE, while the linear-cyclic enolate isomerization is induced by green light and heat. Density functional theory and molecular dynamics calculation results suggest that the steric effect and supramolecular interaction between the electron-donating and electron-withdrawing moieties play an important role in hindering the tautomerization between cyclic keto and cyclic enolate DASA-CE. The strategy to influence key steps in the photoswitching process inspires well-controlled multistage isomerization of photoresponsive molecules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crown Ethers*
  • Isomerism
  • Molecular Dynamics Simulation*

Substances

  • Crown Ethers