Center for Molecular Modeling - A. Krylov

Unfolding the terahertz spectrum of soft porous crystals: rigid unit modes and their impact on phase transitions

alexander — Thu, 16 Jun 2022 08:47:33 +0000

A.E.J. Hoffman, I. Senkovska, J. Wieme, A. Krylov, S. Kaskel, V. Van Speybroeck

Journal of Materials Chemistry A

10 (33), 17254-17266

2022

Abstract

Phase transitions in exible metal-organic frameworks or soft porous crystals are mediated by low-frequency phonons or rigid-unit modes. The alteration of specic building blocks may change the lattice dynamics of these frameworks, which can inuence the phase transition mechanism. In this work, the impact of building block substitution on the rigid-unit modes in exible MIL-53 analogs with a winerack topology will be investigated via ab initio lattice dynamics calculations. First, the accuracy of the theoretical simulations is veried via experimental Raman measurements, which provide unique ngerprint 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 eect on the rigid-unit mode frequencies, whereas this is less so for inorganic chain substitutions. These ndings may help to rationally tune the phonon frequencies in soft porous crystals.

Gold Open Access

DOI

http://dx.doi.org/10.1039/d2ta01678h

Private attachment

PublishedPaper.pdf

Unfolding the terahertz spectrum of soft porous crystals: rigid unit modes and their impact on phonon properties

alexander — Mon, 12 Sep 2022 12:24:50 +0000

A.E.J. Hoffman, J. Wieme, I. Senkovska, A. Krylov, S. Kaskel, V. Van Speybroeck

ISBN/ISSN:

Talk

Conference / event / venue

MOF2022

Dresden, Germany

Sunday, 4 September, 2022 to Wednesday, 7 September, 2022

Abstract (private)

Abstract_MOF2022_AlexanderHoffman.pdf

Tuning terahertz vibrations to control flexibility in soft porous crystals

alexander — Fri, 17 Sep 2021 09:02:04 +0000

A.E.J. Hoffman, J. Wieme, I. Senkovska, A. Krylov, S.M.J. Rogge, S. Kaskel, V. Van Speybroeck

ISBN/ISSN:

Poster

Conference / event / venue

EuroMOF2021

Krakow, Poland (online)

Monday, 13 September, 2021 to Wednesday, 15 September, 2021