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Ultraslow Dynamics of a Framework Linker in MIL-53 (Al) as a Sensor for Different Isomers of Xylene. / Khudozhitkov, Alexander E.; Jobic, Hervé; Freude, Dieter и др.
в: Journal of Physical Chemistry C, Том 120, № 38, 29.09.2016, стр. 21704-21709.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Ultraslow Dynamics of a Framework Linker in MIL-53 (Al) as a Sensor for Different Isomers of Xylene
AU - Khudozhitkov, Alexander E.
AU - Jobic, Hervé
AU - Freude, Dieter
AU - Haase, Juergen
AU - Kolokolov, Daniil I.
AU - Stepanov, Alexander G.
PY - 2016/9/29
Y1 - 2016/9/29
N2 - MIL-53 (Al) is an important example of metal-organic frameworks (MOFs) with a flexible framework capable to efficiently separate ortho and para isomers of xylene at moderate temperatures. The MIL-53 MOF contains mobile terephthalate phenylene fragments that can be used as a dynamic probe to investigate the guest-host interactions and the origin of the separation selectivity. Here 2H NMR spin alignment echo technique for the first time was applied to probe ultraslow structural mobility (0.1-1 kHz) in MOFs materials, with particular application to MIL-53(Al) saturated with ortho or para isomers of xylene. A specific influence of different isomers of xylene adsorbed in the MOF pores on the rotation of the phenylenes in MIL-53 for the temperature range with proved separation selectivity (T < 393 K) is shown. It has been established that the rotation of phenylene fragments is sensitive to the type of xylene isomer. The phenylenes' rotation performs 1 order of magnitude slower in the presence of o-xylene (kortho = 70 s-1) compared to the same rotation in the presence of the other isomer, p-xylene (kpara = 800 s-1) at T ∼ 373 K. This is rationalized by a stronger interaction of the ortho isomer with the linker than the para isomer. This finding offers an understanding of the molecular mechanism of p- and o-xylene separation by MIL-53: stronger interaction of o-xylene with organic linker compared to p-xylene provides separation of these isomers on MIL-53.
AB - MIL-53 (Al) is an important example of metal-organic frameworks (MOFs) with a flexible framework capable to efficiently separate ortho and para isomers of xylene at moderate temperatures. The MIL-53 MOF contains mobile terephthalate phenylene fragments that can be used as a dynamic probe to investigate the guest-host interactions and the origin of the separation selectivity. Here 2H NMR spin alignment echo technique for the first time was applied to probe ultraslow structural mobility (0.1-1 kHz) in MOFs materials, with particular application to MIL-53(Al) saturated with ortho or para isomers of xylene. A specific influence of different isomers of xylene adsorbed in the MOF pores on the rotation of the phenylenes in MIL-53 for the temperature range with proved separation selectivity (T < 393 K) is shown. It has been established that the rotation of phenylene fragments is sensitive to the type of xylene isomer. The phenylenes' rotation performs 1 order of magnitude slower in the presence of o-xylene (kortho = 70 s-1) compared to the same rotation in the presence of the other isomer, p-xylene (kpara = 800 s-1) at T ∼ 373 K. This is rationalized by a stronger interaction of the ortho isomer with the linker than the para isomer. This finding offers an understanding of the molecular mechanism of p- and o-xylene separation by MIL-53: stronger interaction of o-xylene with organic linker compared to p-xylene provides separation of these isomers on MIL-53.
UR - http://www.scopus.com/inward/record.url?scp=84989808827&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.6b08114
DO - 10.1021/acs.jpcc.6b08114
M3 - Article
AN - SCOPUS:84989808827
VL - 120
SP - 21704
EP - 21709
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 38
ER -
ID: 23318774