RT Journal Article
T1 Impact of Small Adsorbates in the Vibrational Spectra of Mg- and Zn-MOF-74 Revealed by First-Principles Calculations
A1 Romero-Muñiz, Carlos
A1 Gavira-Vallejo, José María
A1 Merkling, Patrick
A1 Calero, Sofía
K1 Metal−organic framework
K1 MOF-74
K1 Vibrational spectroscopy
K1 Density functional theory
K1 Gas adsorption
AB In this work, we analyze the influence of small adsorbates on the vibrational spectra of Mg- and Zn-metal−organic framework MOF-74 by means of first-principles calculations. In particular, we consider the adsorption of four representative species of different interaction strengths: Ar, CO2, H2O, and NH3. Apart from a comprehensive characterization of the structural and energetic aspects of empty and loaded MOFs, we use a fully quantum ab initio approach to evaluate the Raman and IR activities of the normal modes, leading to the construction of the wholevibrational spectra. Under this approach, not only are we able to proceed with the complete assignment of the spectra in terms of the usual internal coordinates but also we can discern the most relevant vibrational fingerprints of the adsorbates and their impact on the whole MOF spectra. On the one hand, some of the typical vibrational modes of the small molecules are slightly shifted but still visible when adsorbed on the MOFs, especially those appearing at high wavenumbers where the empty MOFs lack IR/Raman signals. On the other hand, some bands arising from the organic ligands are affected by the presence of the absorbates, displaying non-negligible frequency shifts, in agreement with recent experiments. We find a strong correlation between all of these frequency shifts and the interaction strength of the adsorbate with the hosting framework. The findings presented in this work expand the capabilities of vibrational spectroscopy techniques to analyze porous materials and can be useful for the design of sensors and new devices based on MOF technology.
PB American Chemical Society
YR 2020
FD 2020
LK https://hdl.handle.net/10433/19941
UL https://hdl.handle.net/10433/19941
LA en
NO ACS Appl. Mater. Interfaces 2020, volume 12, pp. 54980−54990
NO C.R.-M. acknowledges funding from the Spanish MICINN via the Juan de la Cierva-Formación program (ref FJC2018-036832) and previously from the scholarship program “Oportunidad al Talento” of Fundación ONCE. SpanishMICINN is acknowledged for the funding of a national project (ref PID2019-111189GB-I00). The authors also thank C3UPO for the HPC support.
NO This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Appl. Mater. Interfaces 2020, 12, 49, 54980–54990Publication Date:November 22, 2020https://doi.org/10.1021/acsami.0c16629Copyright © 2020 American Chemical Society
NO Universidad Pablo de Olavide, Departamento de Sistemas Físicos, Químicos y Naturales
DS RIO
RD May 6, 2026