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Dynamics of Xylene Isomers in MIL-53 (Al) MOF Probed by Solid State 2H NMR Full article

Journal Microporous and Mesoporous Materials
ISSN: 1387-1811 , E-ISSN: 1873-3093
Output data Year: 2020, Volume: 300, Article number : 110155, Pages count : 10 DOI: 10.1016/j.micromeso.2020.110155
Tags 2H NMR; Dynamics; MIL-53; MOF; Xylene
Authors Khudozhitkov Alexander E. 1,2 , Arzumanov Sergei S. 1,2 , Kolokolov Daniil I. 1,2 , Stepanov Alexander G. 1
Affiliations
1 Boreskov Institute of Catalysis, Siberian Branch of Russian Academy of Sciences, Prospekt Akademika Lavrentieva 5, Novosibirsk, 630090, Russia
2 Novosibirsk State University, Pirogova Street 2, Novosibirsk, 630090, Russia

Funding (3)

1 Russian Science Foundation 17-73-10135
2 Federal Agency for Scientific Organizations 0303-2016-0003
3 Russian Foundation for Basic Research 18-29-04009

Abstract: With regard to understanding the effect of the dynamics of xylenes confined in the MOFs pores on the origin of xylene isomers separation, the mobility of para and ortho isomers of xylene in MIL-53(Al) MOF has been studied by solid-state 2H NMR. It is inferred that both isomers perform rotational and librational motions of the aromatic ring plane. The geometry, rates and energy barriers of the detected rotational modes for the molecules confined in the channels have been determined. The rotation around the axis perpendicular to the plane of aromatic ring is obliged with pairwise arrangement of xylene molecules along 1D channels of the MOF. The evolution of motional patterns with temperature shows that the pairwise arrangement of ortho isomer in the channels is held till 300 K, whereas the pairs are stable up to 405 K for the para isomer. This was rationalized by stronger interaction of o-xylene with the channel walls, while π–π intermolecular interaction is stronger for p-xylene. Due to stronger interaction between the unpaired molecules and MOF walls o-xylene exhibits notably higher temperature of the molecules desorption from the channels (494 K). In contrast, the p-xylene is capable to leave the channels of MIL-53 already at 405 K, moving in the channels predominantly in pairs. The different motional behavior of xylene isomers provides the conditions for a faster translational mobility along the MOF channel of para compared to the ortho isomer, thus accounting for the molecular mechanism behind the separation selectivity for xylene isomers. © 2020 Elsevier Inc.
Cite: Khudozhitkov A.E. , Arzumanov S.S. , Kolokolov D.I. , Stepanov A.G.
Dynamics of Xylene Isomers in MIL-53 (Al) MOF Probed by Solid State 2H NMR
Microporous and Mesoporous Materials. 2020. V.300. 110155 :1-10. DOI: 10.1016/j.micromeso.2020.110155 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
Submitted: Feb 4, 2020
Accepted: Mar 6, 2020
Published online: Mar 9, 2020
Published print: Jun 15, 2020
Identifiers:
Web of science: WOS:000527329400018
Scopus: 2-s2.0-85081678141
Elibrary: 43254913
Chemical Abstracts: 2020:542722
Chemical Abstracts (print): 172:497345
OpenAlex: W3009829853
Citing:
DB Citing
Scopus 18
Web of science 17
Elibrary 14
OpenAlex 20
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