Uncovering the Rotation and Translational Mobility of Benzene Confined in UiO-66 (Zr) Metal–Organic Framework by the 2H NMR–QENS Experimental Toolbox | Sciact - CRIS-system of Boreskov Institute of Catalysis

Uncovering the Rotation and Translational Mobility of Benzene Confined in UiO-66 (Zr) Metal–Organic Framework by the 2H NMR–QENS Experimental Toolbox Full article

Journal

The Journal of Physical Chemistry C
ISSN: 1932-7447 , E-ISSN: 1932-7455

Output data

Year: 2017, Volume: 121, Number: 5, Pages: 2844-2857 Pages count : 14 DOI: 10.1021/acs.jpcc.6b12001

Tags

Activation energy; Benzene; Chemical activation; Crystalline materials; Diffusion; Neutron scattering; Nuclear magnetic resonance; Organometallics; Rate constants; Rotation

Authors

Kolokolov Daniil I. ^1,2 , Maryasov Alexander G. ³ , Ollivier Jacques ⁴ , Freude Dieter ⁵ , Haase Jürgen ⁵ , Stepanov Alexander G. ^1,2 , Jobic Hervé ⁶

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
3	Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian Academy of Sciences, Institutskaya Street 3, 630090 Novosibirsk, Russia
4	Institut Laue Langevin, BP 156, 38042 Grenoble, France
5	Fakultat fur Physik und Geowissenschaften, Universitat Leipzig, Linne ̈ straße 5, 04103 Leipzig, Germany
6	Institut de Recherches sur la Catalyse et l’Environnement de Lyon, CNRS, Universitéde Lyon, 2. Av. A. Einstein, 69626, Villeurbanne, France

Funding (3)

1	Russian Foundation for Basic Research	14-03-91333
2	Federal Agency for Scientific Organizations	0303-2016-0003
3	German Research Foundation	HA 1893/16

A combination of experimental quasi-elastic neutron scattering (QENS) and deuterium solid-state nuclear magnetic resonance (2H NMR) techniques was used to uncover the molecular mobility of benzene confined in UiO-66 (Zr) MOF with a 3D cage-window-cage type porous network topology. We have shown that tetrahedral and octahedral cages of UiO-66 offer notably different states of confinement for benzene. Below 163 K, the guest molecules of benzene are represented by two different dynamic states: in the smaller (tetrahedral) cage the benzene is able to exhibit only anisotropic C6 rotation and some limited librations. In the octahedral cage, there is enough space for additional C2 axial rotation and the isotropic random reorientation. Rotational motions have been characterized by the rate constants and corresponding activation energies. The two dynamic states merge as the temperature increases due to translational jump diffusion with the limiting step being the passage through the window between the cages. Both techniques show similar activation barrier for the diffusion of 25–27 kJ mol–1 and a diffusion coefficient D = 3.3 × 10–11 m2 s–1 at 400 K. The diffusion process is described by a migration via 1 nm long jumps among octa- and tetrahedral cages. The 2H NMR gives the correlation times for both the elementary step of diffusion (jump exchange between neighboring octa- and tetrahedral cages) and ≈58 time slower long-range isotropic migration process.

Kolokolov D.I. , Maryasov A.G. , Ollivier J. , Freude D. , Haase J. , Stepanov A.G. , Jobic H.
Uncovering the Rotation and Translational Mobility of Benzene Confined in UiO-66 (Zr) Metal–Organic Framework by the 2H NMR–QENS Experimental Toolbox

The Journal of Physical Chemistry C. 2017. V.121. N5. P.2844-2857. DOI: 10.1021/acs.jpcc.6b12001 WOS Scopus РИНЦ ANCAN OpenAlex

Full text from publisher

Submitted:	Nov 29, 2016
Accepted:	Jan 23, 2017
Published online:	Feb 1, 2017
Published print:	Feb 9, 2017

Web of science:	WOS:000394080900041
Scopus:	2-s2.0-85026995505
Elibrary:	29748710
Chemical Abstracts:	2017:142414
Chemical Abstracts (print):	166:203352
OpenAlex:	W2580771389

DB	Citing
Web of science	34
Scopus	34
Elibrary	29
OpenAlex	36