Phonons and Adsorption-Induced Deformations in ZIFs: Is It Really a Gate Opening?

Filip Formalik (1) , Bartosz Mazur (2) , Michael Fischer (3) , Lucyna Firlej (1, 2) , Bogdan Kuchta (4, 5, 2)

1 L2C - Laboratoire Charles Coulomb
2 Faculty of Chemistry, Wroclaw University of Technology
3 Faculty of Geosciences, University of Bremen
4 MADIREL - Matériaux divisés, interfaces, réactivité, électrochimie
5 AMU - Aix Marseille Université

We report a microscopic model of the phonon-adsorption correlations in flexible metal−organic framework materials. We analyze the mechanism of the gate opening deformation using the notion of coupled phonon- and adsorption-induced structural transformation. Using the ZIF-8 structure as an example, we perform an analysis of transformation-related, low-frequency phonon modes of the framework. On the basis of structure-related quantities such as pore limiting diameter, void fraction, and adsorption uptake, we determine the conditions which lead to the gate opening transformation in ZIF-8. Energetic landscape of the deformation process is analyzed using grand thermodynamic potential of adsorption. We generalize our conclusions to other flexible ZIF structures with the same topology.

Domains: Chemical Sciences; Material chemistry

Filip Formalik, Bartosz Mazur, Michael Fischer, Lucyna Firlej, Bogdan Kuchta. Phonons and Adsorption-Induced Deformations in ZIFs: Is It Really a Gate Opening?. Journal of Physical Chemistry C, 2021, 125 (14), pp.7999-8005. ⟨10.1021/acs.jpcc.1c01342⟩. ⟨hal-03226590⟩