Photoswitchable Sol-Gel Transitions and Catalysis Mediated by Polymer Networks with Coumarin-Decorated Cu24 L24 Metal-Organic Cages as Junctions.


Journal Article

Photoresponsive materials that change in response to light have been studied for a range of applications. These materials are often metastable during irradiation, returning to their pre-irradiated state after removal of the light source. Herein, we report a polymer gel comprising poly(ethylene glycol) star polymers linked by Cu24 L24 metal-organic cages/polyhedra (MOCs) with coumarin ligands. In the presence of UV light, a photosensitizer, and a hydrogen donor, this "polyMOC" material can be reversibly switched between CuII , CuI , and Cu0 . The instability of the MOC junctions in the CuI and Cu0 states leads to network disassembly, forming CuI /Cu0 solutions, respectively, that are stable until re-oxidation to CuII and supramolecular gelation. This reversible disassembly of the polyMOC network can occur in the presence of a fixed covalent second network generated in situ by copper-catalyzed azide-alkyne cycloaddition (CuAAC), providing interpenetrating supramolecular and covalent networks.

Full Text

Duke Authors

Cited Authors

  • Oldenhuis, NJ; Qin, KP; Wang, S; Ye, H-Z; Alt, EA; Willard, AP; Van Voorhis, T; Craig, SL; Johnson, JA

Published Date

  • February 2020

Published In

Volume / Issue

  • 59 / 7

Start / End Page

  • 2784 - 2792

PubMed ID

  • 31742840

Pubmed Central ID

  • 31742840

Electronic International Standard Serial Number (EISSN)

  • 1521-3773

International Standard Serial Number (ISSN)

  • 1433-7851

Digital Object Identifier (DOI)

  • 10.1002/anie.201913297


  • eng