Materials Science

Cooperative Light-Induced Breathing of Soft Porous Crystals via Azobenzene Buckling

Abstract

Although light is a prominent stimulus for smart materials, the application of photoswitches as light-responsive triggers for phase transitions of porous materials remains poorly explored. Here we incorporate an azobenzene photoswitch in the backbone of a metal-organic framework producing light-induced structural contraction of the porous network in parallel to gas adsorption. Light-stimulation enables non-invasive spatiotemporal control over the mechanical properties of the framework, which ultimately leads to pore contraction and subsequent guest release via negative gas adsorption. The complex mechanism of light-gated breathing is established by a series of in situ diffraction and spectroscopic experiments, supported by quantum mechanical and molecular dynamic simulations. Unexpectedly, this study identifies a novel light-induced deformation mechanism of constrained azobenzene photoswitches relevant to the future design of light-responsive materials.

Version notes

Version 1.0 - initial submission

Content

Thumbnail image of 2020-11-20 Light-responsive MOF-manuscript.pdf

Supplementary material

Thumbnail image of 2020-11-20 Light-responsive MOF-ESI.pdf
2020-11-20 Light-responsive MOF-ESI
Thumbnail image of Supplementary video 1.mp4
Supplementary video 1
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Supplementary video 2
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Supplementary video 3
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Supplementary video 4