Amine Dynamics in Diamine-Appended Mg2(dobpdc) Metal–Organic Frameworks
- Nankai Univ., Tianjin (China); Univ. of California, Berkeley, CA (United States)
- Univ. of California, Berkeley, CA (United States)
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Univ. of California, Berkeley, CA (United States); East China Univ. of Science and Technology, Shanghai (China)
- College of William and Mary, Williamsburg, VA (United States)
- Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division
- Univ. of California, Berkeley, CA (United States); Valais Ecole Polytechnique Fédérale de Lausanne (EPFL), Sion (Switzerland)
In this work, variable-temperature 15N solid-state NMR spectroscopy is used to uncover the dynamics of three diamines appended to the metal–organic framework Mg2(dobpdc) (dobpdc4– = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate), an important family of CO2 capture materials. The results imply both bound and free amine nitrogen environments exist when diamines are coordinated to the framework open Mg2+ sites. There are rapid exchanges between two nitrogen environments for all three diamines, the rates and energetics of which are quantified by 15N solid-state NMR data and corroborated by density functional theory calculations and molecular dynamics simulations. The activation energy for the exchange provides a measure of the metal–amine bond strength. The unexpected negative correlation between the metal–amine bond strength and CO2 adsorption step pressure reveals that metal–amine bond strength is not the only important factor in determining the CO2 adsorption properties of diamine-appended Mg2(dobpdc) metal–organic frameworks.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Center for Gas Separations Relevant to Clean Energy Technologies (CGS); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Biological and Environmental Research (BER); National Institutes of Health (NIH); National Science foundation (NSF); National Institute of General Medical Sciences (NIGMS); National Natural Science Foundation of China (NSFC); State Key Laboratory of Fine Chemicals
- Grant/Contract Number:
- AC05-76RL01830; SC0001015; S10OD023532; AC02-05CH11231
- OSTI ID:
- 1602785
- Alternate ID(s):
- OSTI ID: 1605261
- Report Number(s):
- PNNL-SA-131857
- Journal Information:
- Journal of Physical Chemistry Letters, Vol. 10, Issue 22; ISSN 1948-7185
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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