Charge-Separated and Lewis Paired Metal-Organic Framework for Anion Exchange and CO2 Chemical Fixation

Sheela Thapa; Lingyao Meng; Eshani Hettiarachchi; Yousef K Bader; Diane A Dickie; Gayan Rubasinghege; Sergei A Ivanov; Erika C Vreeland; Yang Qin

doi:10.1002/chem.202002823

Charge-Separated and Lewis Paired Metal-Organic Framework for Anion Exchange and CO₂ Chemical Fixation

Chemistry. 2020 Nov 2;26(61):13788-13791. doi: 10.1002/chem.202002823. Epub 2020 Oct 16.

Authors

Sheela Thapa¹, Lingyao Meng¹, Eshani Hettiarachchi², Yousef K Bader¹, Diane A Dickie³, Gayan Rubasinghege², Sergei A Ivanov⁴, Erika C Vreeland⁵, Yang Qin¹

Affiliations

¹ Department of Chemistry & Chemical Biology, University of New Mexico, MSC03-2060 1 UNM, Albuquerque, NM, 87131, USA.
² Department of Chemistry, New Mexico Institute of Mining and Technology, 801 Leroy Pl., Socorro, NM 87801, USA.
³ Department of Chemistry, University of Virginia, 409 McCormick Rd., Charlottesville, VA, 22904, USA.
⁴ Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Bikini Atoll Rd., SM30, Los Alamos, NM 87801, USA.
⁵ IR Dynamics, LLC, 6901 Gruber Ave. NE, Suite G, Albuquerque, NM, 87109, USA.

PMID: 32619313
DOI: 10.1002/chem.202002823

Abstract

Charge-separated metal-organic frameworks (MOFs) are a unique class of MOFs that can possess added properties originating from the exposed ionic species. A new charge-separated MOF, namely, UNM-6 synthesized from a tetrahedral borate ligand and Co²⁺ cation is reported herein. UNM-6 crystalizes into the highly symmetric P43n space group with fourfold interpenetration, despite the stoichiometric imbalance between the B and Co atoms, which also leads to loosely bound NO₃ ^- anions within the crystal structure. These NO₃ ^- ions can be quantitatively exchanged with various other anions, leading to Lewis acid (Co²⁺ ) and Lewis base (anions) pairs within the pores and potentially cooperative catalytic activities. For example, UNM-6-Br, the MOF after anion exchange with Br^- anions, displays high catalytic activity and stability in reactions of CO₂ chemical fixation into cyclic carbonates.

Keywords: anion exchange; boron; chemical fixation of carbon dioxide; cyclic carbonates; metal-organic frameworks.

Abstract

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