Unfolding the terahertz spectrum of soft porous crystals: rigid unit modes and their impact on phase transitions
Hoffman AEJ, Senkovska I, Wieme J, Krylov A, Kaskel S, Van Speybroeck V (2022)
Publication Type: Journal article
Publication year: 2022
Journal
Book Volume: 10
Pages Range: 17254-17266
Journal Issue: 33
DOI: 10.1039/d2ta01678h
Abstract
Phase transitions in flexible metal-organic frameworks or soft porous crystals are mediated by low-frequency phonons or rigid-unit modes. The alteration of specific building blocks may change the lattice dynamics of these frameworks, which can influence the phase transition mechanism. In this work, the impact of building block substitution on the rigid-unit modes in flexible MIL-53 analogs with a winerack topology will be investigated via ab initio lattice dynamics calculations. First, the accuracy of the theoretical simulations is verified via experimental Raman measurements, which provide unique fingerprint vibrations in the terahertz range to characterize the phase transition. Following analysis of the low-frequency vibrations shows that there exists a set of universal rigid-unit modes inducing translations and/or rotations of the building blocks. The theoretical results demonstrate that linker substitutions have a large effect on the rigid-unit mode frequencies, whereas this is less so for inorganic chain substitutions. These findings may help to rationally tune the phonon frequencies in soft porous crystals.
Involved external institutions
Technische Universität Dresden
Germany (DE)
Universiteit Gent (UGent) / Ghent University
Belgium (BE)
Federal Research Center "Krasnoyarsk Science Center of the Siberian Branch of the Russian Academy of Sciences"
Russian Federation (RU)
Germany (DE)
Universiteit Gent (UGent) / Ghent University
Belgium (BE)
Federal Research Center "Krasnoyarsk Science Center of the Siberian Branch of the Russian Academy of Sciences"
Russian Federation (RU)
How to cite
APA:
Hoffman, A.E.J., Senkovska, I., Wieme, J., Krylov, A., Kaskel, S., & Van Speybroeck, V. (2022). Unfolding the terahertz spectrum of soft porous crystals: rigid unit modes and their impact on phase transitions. Journal of Materials Chemistry A, 10(33), 17254-17266. https://doi.org/10.1039/d2ta01678h
MLA:
Hoffman, Alexander E. J., et al. "Unfolding the terahertz spectrum of soft porous crystals: rigid unit modes and their impact on phase transitions." Journal of Materials Chemistry A 10.33 (2022): 17254-17266.
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