https://doi.org/10.1051/epjap/2011100370
NMR studies of benzene mobility in metal-organic framework MOF-5
1
Fakultät für Physik und Geowissenschaften, Universität Leipzig, Linnéstrasse 5, 04103 Leipzig, Germany
2
Lehrstuhl für Anorganische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
3
Fakultät für Chemie und Mineralogie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
a e-mail: stallmac@physik.uni-leipzig.de
Received:
27
September
2010
Accepted:
18
April
2011
Published online:
11
August
2011
The concentration and temperature dependence of the self-diffusion of benzene adsorbed in the metal-organic framework MOF-5 (IRMOF-1) is studied by pulsed field gradient (PFG) NMR spectroscopy. When increasing the loading from 10 to 20 molecules per unit cell of MOF-5, the experimental diffusion data drop by a factor of about 3 while current molecular dynamic (MD) simulations predict slightly increasing diffusion coefficients for this range of loadings. The observation is rationalized using the recently predicted clustering of adsorbate molecules in microporous systems for temperatures well below the adsorbate critical temperature. Necessary improvements of molecular simulation models for predicting diffusivities under such conditions are discussed.
© EDP Sciences, 2011
