Dynamic DMF Binding in MOF-5 Enables the Formation of Metastable Cobalt-Substituted MOF-5 Analogues

• Main Authors: Bellarosa, Luca (Author), López, Núria (Author), Brozek, Carl Kavanaugh (Contributor), Michaelis, Vladimir K. (Contributor), Ong, Ta-Chung (Contributor), Griffin, Robert Guy (Contributor), Dinca, Mircea (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Chemistry (Contributor), Francis Bitter Magnet Laboratory (Massachusetts Institute of Technology) (Contributor)
• Format: Article
• Language: English
• Published: American Chemical Society (ACS), 2016-11-01T16:05:40Z.
• Subjects: Article
• Online Access: Get fulltext

 Multinuclear solid-state nuclear magnetic resonance, mass spectrometry, first-principles molecular dynamics simulations, and other complementary evidence reveal that the coordination environment around the Zn2+ ions in MOF-5, one of the most iconic materials among metal-organic frameworks (MOFs), is not rigid. The Zn2+ ions bind solvent molecules, thereby increasing their coordination number, and dynamically dissociate from the framework itself. On average, one ion in each cluster has at least one coordinated N,N-dimethylformamide (DMF) molecule, such that the formula of as-synthesized MOF-5 is defined as Zn4O(BDC)3(DMF)x (x = 1-2). Understanding the dynamic behavior of MOF-5 leads to a rational low-temperature cation exchange approach for the synthesis of metastable Zn4-xCoxO(terephthalate)3 (x > 1) materials, which have not been accessible through typical high-temperature solvothermal routes thus far.