Abstract
The thermo-structural behavior of metal-organic framework (MOF) precursors is responsible for regulating the introduction of defects in MOF structures during synthesis. In this paper, factors affecting the flexibility of MIL-101(Cr) half-secondary building units (half-SBUs) are evaluated in solution using enhanced sampling methods. In particular, entropic and enthalpic contributions to the conformational free energy landscape of isolated MIL-101(Cr) half-SBUs are calculated in water, in the presence and absence of ionic species (Na+ and F−), and in N, N-dimethylformamide (DMF). This analysis leads to the observation that the interplay between enthalpy and entropy determines the most probable conformational state for half-SBUs. This observation extends to the most relevant SBU intermediate, in which conformational entropy plays a key role in stabilizing configurations that differ from those found in the MIL-101(Cr) crystal structure. The findings highlight the importance of explicitly considering entropic effects, associated with finite-temperature sampling when estimating the relative stability of different conformers of SBUs.
| Original language | English |
|---|---|
| Article number | 2000092 |
| Journal | Advanced Theory and Simulations |
| Volume | 3 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 2020 |
| Externally published | Yes |
Funding
The work described in this publication was performed at Pacific Northwest National Laboratory (PNNL), which is operated by Battelle for the United States Department of Energy (DOE) under Contract DE‐AC05‐76RL0180. V.‐A. G. and R. R. acknowledge support from the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. L. K. was partially supported by a Laboratory Directed Research and Development grant for PNNL. D.C.C. acknowledges support from Research and Innovation at the University of Nevada, Reno. The authors acknowledge the use of the UCL Myriad High Throughput Computing Facility (Myriad@UCL), and associated support services, in the completion of this work. The authors are grateful to the UK Materials and Molecular Modelling Hub for computational resources, which was partially funded by EPSRC (EP/P020194/1). This research used resources provided by the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. DE‐AC02‐05CH11231. The work described in this publication was performed at Pacific Northwest National Laboratory (PNNL), which is operated by Battelle for the United States Department of Energy (DOE) under Contract DE-AC05-76RL0180. V.-A. G. and R. R. acknowledge support from the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. L. K. was partially supported by a Laboratory Directed Research and Development grant for PNNL. D.C.C. acknowledges support from Research and Innovation at the University of Nevada, Reno. The authors acknowledge the use of the UCL Myriad High Throughput Computing Facility (Myriad@UCL), and associated support services, in the completion of this work. The authors are grateful to the UK Materials and Molecular Modelling Hub for computational resources, which was partially funded by EPSRC (EP/P020194/1). This research used resources provided by the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231.
| Funders | Funder number |
|---|---|
| Office of Basic Energy Sciences | |
| Research and Innovation at the University of Nevada, Reno | |
| U.S. Department of Energy Office of Science | DE-AC02-05CH11231 |
| UCL Myriad High Throughput Computing Facility | |
| United States Department of Energy | |
| U.S. Department of Energy | DE‐AC02‐05CH11231, DE‐AC05‐76RL0180 |
| Office of Science | |
| Basic Energy Sciences | |
| Laboratory Directed Research and Development | |
| University of Nevada, Reno | |
| Pacific Northwest National Laboratory | |
| Chemical Sciences, Geosciences, and Biosciences Division | |
| Engineering and Physical Sciences Research Council | EP/P020194/1 |
Keywords
- entropy
- metal-organic frameworks
- molecular dynamics