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Variation in the Sorption Properties of a Pair of Highly Flexible, Isostructural MOFs Exhibiting Single-Crystal-to-Single-Crystal Transformations Rarely Observed in MOFs Based on a Linear Co3/Mn3 Trinuclear Cluster

Year: 2024

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Two mixed-ligand metal–organic frameworks (MOFs), [Co 3 (ia) 3 (bppdo)(MeOH)] n · n (DMF) ( 1 ) and [Mn 3 (ia) 3 (bppdo)(MeOH)] n · n (DMF) ( 2 ), have been synthesized, where ia = isophthalate, bppdo = 1,3-bis(4-pyridyl)propane- N, N ′-dioxide, MeOH = methanol, and DMF = N, N ′-dimethylformamide. Single-crystal X-ray diffraction studies reveal that 1 and 2, based on a linear Co 3 and Mn 3 cluster, respectively, are isoreticular and isostructural and possess two-periodic frameworks consisting of linear trinuclear metal clusters. Variable-temperature single-crystal X-ray diffraction studies confirm single-crystal-to-single-crystal transformations (rarely observed for MOFs based on a linear Co 3 /Mn 3 cluster) upon desolvation and subsequent hydration, despite significant structural changes occurring. The desolvated structures ( 1′ and 2′ ) show a drastic reduction in their void spaces (3.7 and 5.7% for 1′ and 2′, respectively, at 298 K) as compared to their as-synthesized structures (potential void spaces of 21.6 and 22.3% for 1 and 2, respectively, at 298 K). Despite the similar void spaces at 195 K that are also seemingly inaccessible, significant CO 2 sorption occurs at this temperature for 1′ and 2′, indicating that structural changes had to occur in order to accommodate the adsorbed CO 2 molecules. Water vapor sorption at 298 K also induces structural changes in 1′ and 2′ as confirmed by single-crystal X-ray diffraction studies. The structural transformations that occur during desolvation and sorption processes emphasize the remarkable dynamic nature of these frameworks in responding to their environment.

Source: Crystal Growth & Design

DOI: 10.1021/acs.cgd.4c00884

Authors: Kedibone G. Muguru, Wilson Mogodi, Clive L. Oliver

Institution: University of Cape Town

Language: English

Topic: Metal-Organic Frameworks: Synthesis and Applications

Subfield: Inorganic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: National Research Foundation, University of Capetown, University of Cape Town