Research output: Contribution to journal › Article › peer-review
Probing Gas Adsorption in Metal-Organic Framework ZIF-8 by EPR of Embedded Nitroxides. / Sheveleva, A. M.; Anikeenko, A. V.; Poryvaev, A. S. et al.
In: Journal of Physical Chemistry C, Vol. 121, No. 36, 14.09.2017, p. 19880-19886.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Probing Gas Adsorption in Metal-Organic Framework ZIF-8 by EPR of Embedded Nitroxides
AU - Sheveleva, A. M.
AU - Anikeenko, A. V.
AU - Poryvaev, A. S.
AU - Kuzmina, D. L.
AU - Shundrina, I. K.
AU - Kolokolov, D. I.
AU - Stepanov, A. G.
AU - Fedin, M. V.
N1 - Publisher Copyright: © 2017 American Chemical Society.
PY - 2017/9/14
Y1 - 2017/9/14
N2 - Metal-organic frameworks (MOFs) are being increasingly considered as promising materials for gas separation and storage, yet specific interactions between gas molecules and the inner surface of pores are still not well understood. In this work, we propose a new approach for investigation of such interactions by Electron Paramagnetic Resonance (EPR). We use stable nitroxide radicals as multifunctional agents embedded into the pores of a MOF prior to the gas sorption. They act as EPR-active reporters, and simultaneously as competitor molecules during the gas adsorption process. We exemplify this approach using a ZIF-8 framework, nitroxide TEMPO ((2,2,6,6-tetramethylpiperidin-1-yl)oxyl), and CO2, N2, and O2 gases. The mobility of nitroxide monitored by continuous wave EPR behaves differently upon adsorption of each of these gases. In particular, a noticeable increase of mobility in the presence of CO2 reveals the weakening of guest-host interactions TEMPO-MOF induced by CO2, which was qualitatively supported by molecular dynamic calculations. The nitroxides can be embedded in MOFs postsynthetically, and their negligible amounts (≤1 per 1000 cells) are required due to a high sensitivity of EPR. Therefore, the proposed approach is sufficiently versatile and might find broad applications for various MOFs.
AB - Metal-organic frameworks (MOFs) are being increasingly considered as promising materials for gas separation and storage, yet specific interactions between gas molecules and the inner surface of pores are still not well understood. In this work, we propose a new approach for investigation of such interactions by Electron Paramagnetic Resonance (EPR). We use stable nitroxide radicals as multifunctional agents embedded into the pores of a MOF prior to the gas sorption. They act as EPR-active reporters, and simultaneously as competitor molecules during the gas adsorption process. We exemplify this approach using a ZIF-8 framework, nitroxide TEMPO ((2,2,6,6-tetramethylpiperidin-1-yl)oxyl), and CO2, N2, and O2 gases. The mobility of nitroxide monitored by continuous wave EPR behaves differently upon adsorption of each of these gases. In particular, a noticeable increase of mobility in the presence of CO2 reveals the weakening of guest-host interactions TEMPO-MOF induced by CO2, which was qualitatively supported by molecular dynamic calculations. The nitroxides can be embedded in MOFs postsynthetically, and their negligible amounts (≤1 per 1000 cells) are required due to a high sensitivity of EPR. Therefore, the proposed approach is sufficiently versatile and might find broad applications for various MOFs.
KW - ELECTRON-PARAMAGNETIC-RESONANCE
KW - CARBON-DIOXIDE
KW - FORCE-FIELD
KW - MOLECULAR-DYNAMICS
KW - IMIDAZOLATE
KW - CO2
KW - MEMBRANES
KW - HYDROGEN
KW - H-2
KW - SELECTIVITY
UR - http://www.scopus.com/inward/record.url?scp=85029536713&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.7b06884
DO - 10.1021/acs.jpcc.7b06884
M3 - Article
AN - SCOPUS:85029536713
VL - 121
SP - 19880
EP - 19886
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 36
ER -
ID: 9030166