Photoresponsive organic cages – computationally inspired discovery of azobenzene-derived organic cages
Author(s)
Type
Journal Article
Abstract
The incorporation of photoresponsive groups into porous materials is attractive as it offers potential advantages in controlling the pore size and selectivity to guest molecules. A combination of computational modeling and experiment resulted in the synthesis of two azobenzene-derived organic cages based on building blocks identified in a computational screen. Both cages incorporate three azobenzene moieties, and are therefore capable of 3-fold isomerization, using either ditopic or tetratopic aldehydes containing diazene functionality. The ditopic aldehyde forms a Tri2Di3 cage via a 6-fold imine condensation and the tritopic aldehyde forms a Tet3Di6 cage via a 12-fold imine condensation. The relative energies and corresponding intrinsic cavities of each isomeric state were computed, and the photoswitching behavior of both cages was studied by UV–Vis and 1H NMR spectroscopy, including a detailed kinetic analysis of the thermal isomerization for each of the EEZ, EZZ and ZZZ metastable isomers of the Tet3Di6 cage. Both cages underwent photoisomerization, where a photostationary state of up to 77% of the cis-isomer and overall thermal half-life of 110 h was identified for the Tet3Di6 species. Overall, this work demonstrates the potential of computational modeling to inform the design of photoresponsive materials and highlights the contrasting effects on the photoswitching properties of the azobenzene moieties on incorporation into the different cage species.
Date Issued
2024-11-06
Date Acceptance
2024-10-08
Citation
Journal of the American Chemical Society, 2024, 146 (44), pp.30332-30339
ISSN
0002-7863
Publisher
American Chemical Society
Start Page
30332
End Page
30339
Journal / Book Title
Journal of the American Chemical Society
Volume
146
Issue
44
Copyright Statement
Copyright © 2024 The Authors. Published by American Chemical Society. This publication is licensed under
CC-BY 4.0 .
CC-BY 4.0 .
License URL
Identifier
https://pubs.acs.org/doi/10.1021/jacs.4c10217
Publication Status
Published
Date Publish Online
2024-10-22