Molecular Mechanism of Loading Sulfur Hexafluoride in γ-Cyclodextrin Metal–Organic Framework

Abstract

γ-Cyclodextrin metal-organic framework (γ-CD-MOF) is a new type of highly porous carrier for potential loading of therapeutic or diagnostic gas like sulfur hexafluoride (SF). Here, loading of SF into γ-CD-MOF was investigated for its mechanism by molecular simulation and quantitative determination of SF using quantitative nuclear magnetic resonance (qNMR). For the SF loading, γ-CD-MOF was first degassed to remove the air without thermal decomposition or loss of framework crystallinity, then placed in the copper tube, and sealed to adsorb SF under 1.2 MPa and 25 °C for 12 h. The qNMR was employed for the determination of SF loaded in γ-CD-MOF using Span 80 as suspending agent and trifluoroacetic acid as internal standard. Then, the thermodynamic parameters had been estimated. Finally, molecular modeling combining with F NMR spectra was conducted to reveal the status of SF molecules in γ-CD-MOF. The results demonstrated that the content of SF loaded in γ-CD-MOF was 2.67 ± 0.46 wt %. After exposing to the environment of free SF at 0.1 MPa for 10 days, the relative content was 74.7%. It was confirmed that SF preferred to stay in the cavity of γ-CD-MOF cubes rather than in the γ-CD molecular pairs, which was a nonchemical adsorptive process. In conclusion, this research has established qNMR method and molecular simulation to demonstrate SF molecules in γ-CD-MOF and its loading mechanism.

Encapsulating quercetin in cyclodextrin metal–organic frameworks improved its solubility and bioavailability

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Role of Pore Volume and Surface Area of Cu‐BTC and MIL‐100 (Fe) Metal‐Organic Frameworks on the Loading of Rifampicin: Collective Experimental and Docking Study

“…The binding energy was found to be −12.8, kcal/mol. for Cu‐BTC with Rif and −9.0 kcal/mol for MIL‐100 (Fe) with Rif [56–58] …”

Study on removal of volatile organic compounds by metal-organic framework composite material

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