Abstract
Quantum tunneling rotors in a zeolitic imidazolate framework ZIF-8 can provide insights into local gas adsorption sites and local dynamics of porous structure, which are inaccessible to standard physisorption or x-ray diffraction sensitive primarily to long-range order. Using in situ high-resolution inelastic neutron scattering at 3 K, we follow the evolution of methyl tunneling with respect to the number of dosed gas molecules. While nitrogen adsorption decreases the energy of the tunneling peak, and ultimately hinders it completely (0.33 meV to zero), argon substantially increases the energy to 0.42 meV. Ab initio calculations of the rotational barrier of ZIF-8 show an exception to the reported adsorption sites hierarchy, resulting in anomalous adsorption behavior and linker dynamics at subatmospheric pressure. The findings reveal quantum tunneling rotors in metal-organic frameworks as a sensitive atomistic probe of local physicochemical phenomena.
| Original language | English |
|---|---|
| Article number | 073402 |
| Journal | Physical Review Materials |
| Volume | 7 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 2023 |
Funding
MMC Laboratory is supported by the ERC Consolidator Grant (PROMOFS Grant Agreement No. 771575) and EPSRC Awards (Grants No. EP/N014960/1 and No. EP/R511742/1). We thank ISIS Facility for the awarded OSIRIS beamtime (Grants No. RB1410426, No. RB1510529, and No. RB1610180), DOIs 10.5286/ISIS.E.RB1410426, 10.5286/ISIS.E.RB1510529, and 10.5286/ISIS.E.RB1610180, as well as the Cryogenics, and Pressure & Furnaces teams for their exemplary support. M.R.R. acknowledges the U.S. DOE Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division (Separation Sciences). This work is further supported by the Fund for Scientific Research Flanders (FWO) through a Ph.D. fellowship for A.L. (Grant No. 11D2220N) and a postdoctoral fellowship for S.M.J.R. (Grant No. 12T3522N). Financial support for F.F.-A. from the Spanish Ministry of Science and Innovation (Grant No. PID2020-114506GB-I00 funded by MCIN/AEI/10.13039/501100011033 and Grant No. TED2021-129457B-I00 funded by MCIN/AEI/10.13039/501100011033 and the European Union NextGenerationEU/PRTR) as well as the Basque Government (Grant No. PIBA-2021-0026) is gratefully acknowledged. We also acknowledge the financial support received from the IKUR Strategy under the collaboration agreement between Ikerbasque Foundation and the Materials Physics Center on behalf of the Department of Education of the Basque Government. We acknowledge the Research Complex at Harwell (RCaH) for access to materials characterization facilities. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation–Flanders (FWO) and the Flemish Government–department EWI.
| Funders | Funder number |
|---|---|
| Department of Education of the Basque Government | |
| European Union NextGenerationEU/PRTR | |
| Flemish Government–department EWI | |
| IKUR | |
| Ikerbasque Foundation | |
| Office of Science | |
| Basic Energy Sciences | |
| Chemical Sciences, Geosciences, and Biosciences Division | |
| Vlaams Supercomputer Centrum | |
| Vermont Studio Center | |
| Engineering and Physical Sciences Research Council | RB1410426, RB1610180, EP/N014960/1, EP/R511742/1, RB1510529 |
| European Research Council | 771575 |
| Eusko Jaurlaritza | PIBA-2021-0026 |
| Fonds Wetenschappelijk Onderzoek | 11D2220N, 12T3522N |
| Ministerio de Ciencia e Innovación | MCIN/AEI/10.13039/501100011033, PID2020-114506GB-I00, TED2021-129457B-I00 |