Elucidating the Vibrational Fingerprint of the Flexible Metal-Organic Framework MIL-53(Al) Using a Combined Experimental/Computational Approach

In this work, mid-infrared (mid-IR), far-IR, and Raman spectra are presented for the distinct (meta)stable phases of the flexible metal-organic framework MIL-53(Al). Static density functional theory (DFT) simulations are performed, allowing for the identification of all IR-active modes, which is unp...

Full description

Saved in:
Bibliographic Details
Published in:Journal of physical chemistry. C Vol. 122; no. 5; p. 2734
Main Authors: Hoffman, Alexander E J, Vanduyfhuys, Louis, Nevjestić, Irena, Wieme, Jelle, Rogge, Sven M J, Depauw, Hannes, Van Der Voort, Pascal, Vrielinck, Henk, Van Speybroeck, Veronique
Format: Journal Article
Language:English
Published: United States 08.02.2018
ISSN:1932-7447
Online Access:Get more information
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In this work, mid-infrared (mid-IR), far-IR, and Raman spectra are presented for the distinct (meta)stable phases of the flexible metal-organic framework MIL-53(Al). Static density functional theory (DFT) simulations are performed, allowing for the identification of all IR-active modes, which is unprecedented in the low-frequency region. A unique vibrational fingerprint is revealed, resulting from aluminum-oxide backbone stretching modes, which can be used to clearly distinguish the IR spectra of the closed- and large-pore phases. Furthermore, molecular dynamics simulations based on a DFT description of the potential energy surface enable determination of the theoretical Raman spectrum of the closed- and large-pore phases for the first time. An excellent correspondence between theory and experiment is observed. Both the low-frequency IR and Raman spectra show major differences in vibrational modes between the closed- and large-pore phases, indicating changes in lattice dynamics between the two structures. In addition, several collective modes related to the breathing mechanism in MIL-53(Al) are identified. In particular, we rationalize the importance of the trampoline-like motion of the linker for the phase transition.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:1932-7447
DOI:10.1021/acs.jpcc.7b11031