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Coordination Chemistry in the Structural and Functional Exploration of Actinide-Based Metal-Organic Frameworks

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Abstract

The coordination chemistry between inorganic and organic species can be optimally exemplified by metal–organic frameworks (MOFs), whose structures and functionalities can be rationally designed from these highly tunable building blocks. The high porosity, stability, and versatile functionalities of MOFs have attracted wide-spread attention from energy-related research and pollution remediation to biomedical applications. A unique and underexplored subset of these materials are MOFs based on actinide nodes; these MOFs have distinguished themselves as a unique platform for investigating the versatile oxidation states, reactivity, and coordination chemistry of actinides. Herein, we will focus on the rational design and synthesis of actinide-based MOFs under the general guidelines of coordination chemistry for their structural and functional explorations. The dimensionality, topology, and structures of actinide-based MOFs can be controlled by selecting pre-designed building blocks of actinide-based nodes and organic linkers with certain desired coordination geometries and functionalities. These unique actinide-based MOFs have shown promise for applications in nuclear waste mitigation, pollution control, and catalysis.

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... Meanwhile, Shustova presented a seminal overview of the structural motifs of Th-, U-MOFs, and MOFs for radionuclide immobilization [26]. Recently, Zhang recorded the structure and functionality of An-MOFs prepared by the Farha group [27] meanwhile the Zhou group summarized MOFs based on group 3 and 4 metals, including several Th-, Np-, and Pu-MOFs [28]. The Park group discussed the coordination environments and chemical behaviors of a portion of An-MOFs, focusing their implications for nuclear industry [29]. ...
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Chapter
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Article
Porous crystals are strategic materials with industrial applications within petrochemistry, catalysis, gas storage, and selective separation. Their unique properties are based on the molecular-scale porous character. However, a principal limitation of zeolites and similar oxide-based materials is the relatively small size of the pores, typically in the range of medium-sized molecules, limiting their use in pharmaceutical and fine chemical applications. Metal organic frameworks (MOFs) provided a breakthrough in this respect. New MOFs appear at a high and an increasing pace, but the appearances of new, stable inorganic building bricks are rare. Here we present a new zirconium-based inorganic building brick that allows the synthesis of very high surface area MOFs with unprecedented stability. The high stability is based on the combination of strong Zr-O bonds and the ability of the inner Zr6-cluster to rearrange reversibly upon removal or addition of mu3-OH groups, without any changes in the connecting carboxylates. The weak thermal, chemical, and mechanical stability of most MOFs is probably the most important property that limits their use in large scale industrial applications. The Zr-MOFs presented in this work have the toughness needed for industrial applications; decomposition temperature above 500 degrees C and resistance to most chemicals, and they remain crystalline even after exposure to 10 tons/cm2 of external pressure.
  • T C Li
  • M Wang
  • O K Delferro
  • Farha
Li, T. C. Wang, M. Delferro, O. K. Farha, Nat. Catal. 2018, 1, 356-362. b) S. M. J. Rogge, A. Bavykina, J. Hajek, H. Garcia, A. I. Olivos-Suarez, A. Sepulveda-Escribano, A. Vimont, G. Clet, P.
  • V Llabres
  • J Van Speybroeck
  • Gascon
Llabres, V. Van Speybroeck, J. Gascon, Chem Soc Rev 2017, 46, 3134-3184. c) S. M. Cohen, Z. Zhang, J. A. Boissonnault, Inorg.
  • O K Zhang
  • Farha
Zhang, O. K. Farha, Angew. Chem. Int. Ed. 2019, 58, 7682-7686.
  • M M Zhang
  • J F Cetin
  • S I Stoddart
  • M R Stupp
  • O K Wasielewski
  • Farha
Zhang, M. M. Cetin, J. F. Stoddart, S. I. Stupp, M. R. Wasielewski, O. K. Farha, J. Am. Chem. Soc. 2020, 142, 1768-1773.
  • X Zhang
  • M R Saber
  • A P Prosvirin
  • J H Reibenspies
  • L Sun
  • M Ballesteros-Rivas
  • H Zhao
  • K R Dunbar
X. Zhang, M. R. Saber, A. P. Prosvirin, J. H. Reibenspies, L. Sun, M. Ballesteros-Rivas, H. Zhao, K. R. Dunbar, Inorg. Chem. Front. 2015, 2, 904-911.
  • T E Farha
  • Z Albrecht-Schmitt
  • S Chai
  • Wang
Farha, T. E. Albrecht-Schmitt, Z. Chai, S. Wang, Nat. Commun. 2018, 9, 3007. b) V. Proust, R. Jeannin, F. D. White, T. E. Albrecht-Schmitt, Inorg. Chem. 2019, 58, 3026-3032.
  • R Birnbaum
  • J W Engle
  • K D John
  • S A Kozimor
  • J S Pacheco
  • L N Redman
R. Birnbaum, J. W. Engle, K. D. John, S. A. Kozimor, J. S. Lezama Pacheco, L. N. Redman, ACS Cent. Sci. 2017, 3, 176-185.
  • S La Pierre
  • S A Kozimor
  • J S Pacheco
  • B W Stein
  • S C E Stieber
  • J J Wilson
S. La Pierre, S. A. Kozimor, J. S. Lezama Pacheco, B. W. Stein, S. C. E. Stieber, J. J. Wilson, Nat. Commun. 2016, 7, 12312. c) C.
  • L Zeller
  • S C Gagliardi
  • Bart
Zeller, L. Gagliardi, S. C. Bart, Nat. Chem. 2017, 9, 850-855. e)
  • K E Knope
  • L Soderholm
K. E. Knope, L. Soderholm, Chem. Rev. 2013, 113, 944-994.
  • N B Loye
  • Shustova
Loye, N. B. Shustova, J. Am. Chem. Soc. 2017, 139, 16852-16861.
  • C Falaise
  • K Kozma
  • M Nyman
C. Falaise, K. Kozma, M. Nyman, Chem.Eur. J. 2018, 24, 14226-14232.
  • B Shustova
B. Shustova, J. Am. Chem. Soc. 2019, 141, 11628-11640. d) Y.
  • Z Li
  • Y Yang
  • Z Wang
  • T Bai
  • X Zheng
  • S Dai
  • D Liu
  • W Gui
  • M Liu
  • L Chen
  • J Chen
  • L Diwu
  • R Zhu
  • Z Zhou
  • T E Chai
  • S Albrecht-Schmitt
  • Wang
Li, Z. Yang, Y. Wang, Z. Bai, T. Zheng, X. Dai, S. Liu, D. Gui, W. Liu, M. Chen, L. Chen, J. Diwu, L. Zhu, R. Zhou, Z. Chai, T. E. Albrecht-Schmitt, S. Wang, Nat. Commun. 2017, 8, 1354.
  • T Loiseau
  • I Mihalcea
  • N Henry
  • C Volkringer
T. Loiseau, I. Mihalcea, N. Henry, C. Volkringer, Coord. Chem. Rev. 2014, 266-267, 69-109.
  • S L Hanna
  • X Zhang
  • K Otake
  • R J Drout
  • P Li
  • T Islamoglu
  • O K Farha
S. L. Hanna, X. Zhang, K.-i. Otake, R. J. Drout, P. Li, T. Islamoglu, O. K. Farha, Cryst. Growth Des. 2019, 19, 506-512.
  • F Chapman
  • T Auras
  • Bein
Chapman, F. Auras, T. Bein, Nat. Chem. 2016, 8, 310-316.
  • C X Bezuidenhout
  • V J Smith
  • C Esterhuysen
  • L J Barbour
C. X. Bezuidenhout, V. J. Smith, C. Esterhuysen, L. J. Barbour, J. Am. Chem. Soc. 2017, 139, 5923-5929. b) S. Furukawa, Y.
  • S Sakata
  • Kitagawa
Sakata, S. Kitagawa, Chem. Lett. 2013, 42, 570-576. c) N. A.
  • G Serre
  • Férey
Serre, G. Férey, Chem. Commun. 2007, 3261-3263.