Publications [#347153] of Stephen L Craig

Journal Articles

1. Oldenhuis, NJ; Qin, KP; Wang, S; Ye, H-Z; Alt, EA; Willard, AP; Van Voorhis, T; Craig, SL; Johnson, JA, Photoswitchable Sol-Gel Transitions and Catalysis Mediated by Polymer Networks with Coumarin-Decorated Cu₂₄ L₂₄ Metal-Organic Cages as Junctions., Angewandte Chemie (International ed. in English), vol. 59 no. 7 (February, 2020), pp. 2784-2792 [doi]
   (last updated on 2026/01/15)

   Abstract:
   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 Cu^II , Cu^I , and Cu⁰ . The instability of the MOC junctions in the Cu^I and Cu⁰ states leads to network disassembly, forming Cu^I /Cu⁰ solutions, respectively, that are stable until re-oxidation to Cu^II 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.