Kinetic Control of Interpenetration in Fe-Biphenyl-4,4′-dicarboxylate Metal-Organic Frameworks by Coordination and Oxidation Modulation

Bara D, Wilson C, Mörtel M, Khusniyarov M, Ling S, Slater B, Sproules S, Forgan RS (2019)

Publication Type: Journal article

Publication year: 2019

Journal

Journal of the American Chemical Society American Chemical Society

DOI: 10.1021/jacs.9b03269

Abstract

Phase control in the self-assembly of metal-organic frameworks (MOFs) is often a case of trial and error; judicious control over a number of synthetic variables is required to select the desired topology and control features such as interpenetration and defectivity. Herein, we present a comprehensive investigation of self-assembly in the Fe-biphenyl-4,4′-dicarboxylate system, demonstrating that coordination modulation can reliably tune between the kinetic product, noninterpenetrated MIL-88D(Fe), and the thermodynamic product, two-fold interpenetrated MIL-126(Fe). Density functional theory simulations reveal that correlated disorder of the terminal anions on the metal clusters results in hydrogen bonding between adjacent nets in the interpenetrated phase and this is the thermodynamic driving force for its formation. Coordination modulation slows self-assembly and therefore selects the thermodynamic product MIL-126(Fe), while offering fine control over defectivity, inducing mesoporosity, but electron microscopy shows MIL-88D(Fe) persists in many samples despite not being evident by diffraction. Interpenetration control is also demonstrated using the 2,2′-bipyridine-5,5′-dicarboxylate linker; it is energetically prohibitive for it to adopt the twisted conformation required to form the interpenetrated phase, although multiple alternative phases are identified due to additional coordination of Fe cations to its N donors. Finally, we introduce oxidation modulation - the use of metal precursors in different oxidation states from that found in the final MOF - to kinetically control self-assembly. Combining coordination and oxidation modulation allows the synthesis of pristine MIL-126(Fe) with BET surface areas close to the predicted maximum for the first time, suggesting that combining the two may be a powerful methodology for the controlled self-assembly of high-valent MOFs.

Authors with CRIS profile

Max Mörtel Lehrstuhl für Anorganische und Allgemeine Chemie Marat Khusniyarov Department Chemie und Pharmazie

Involved external institutions

University of Glasgow GB United Kingdom (GB) University of Nottingham GB United Kingdom (GB) University College London (UCL) GB United Kingdom (GB)

How to cite

APA:

Bara, D., Wilson, C., Mörtel, M., Khusniyarov, M., Ling, S., Slater, B.,... Forgan, R.S. (2019). Kinetic Control of Interpenetration in Fe-Biphenyl-4,4′-dicarboxylate Metal-Organic Frameworks by Coordination and Oxidation Modulation. Journal of the American Chemical Society. https://dx.doi.org/10.1021/jacs.9b03269

MLA:

Bara, Dominic, et al. "Kinetic Control of Interpenetration in Fe-Biphenyl-4,4′-dicarboxylate Metal-Organic Frameworks by Coordination and Oxidation Modulation." Journal of the American Chemical Society (2019).

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