Abstract
Gas capture and sequestration are valuable properties of metal–organic frameworks (MOFs) driving tremendous interest in their use as filtration materials for chemical warfare agents. Recently, the Zr-based MOF UiO-67 was shown to effectively adsorb and decompose the nerve-agent simulant, dimethyl methylphosphonate (DMMP). Understanding mechanisms of MOF-agent interaction is challenging due to the need to distinguish between the roles of the MOF framework and its particular sites for the activation and sequestration process. Here, we demonstrate the quantitative tracking of both framework and binding component structures using in situ X-ray total scattering measurements of UiO-67 under DMMP exposure, pair distribution function analysis, and theoretical calculations. The sorption and desorption of DMMP within the pores, association with linker-deficient Zr6 cores, and decomposition to irreversibly bound methyl methylphosphonate were directly observed and analyzed with atomic resolution.
Highlights
Gas capture and sequestration are valuable properties of metal–organic frameworks (MOFs) driving tremendous interest in their use as filtration materials for chemical warfare agents
This was supported by experimental evidence from in situ X-ray powder diffraction (XRPD), extended X-ray absorption fine structure (EXAFS), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) on MOFs based on Zr6O8 secondary building units interlinked by different organic ligands; sorption of nerve-agent Sarin simulant, dimethyl methylphosphonate (DMMP), leads to binding and decomposition into phosphonate products by the clusters, in particular, irreversibly bidentate-bound methyl methylphosphonate (MMPA)[11]
It was found to be anti-correlated with defect concentration, which could be partially explained by the densification of the MOF with increased defect concentration[56]
Summary
Gas capture and sequestration are valuable properties of metal–organic frameworks (MOFs) driving tremendous interest in their use as filtration materials for chemical warfare agents. Density functional theory (DFT) calculations showed that the degradation of organophosphorus molecules requires nucleophilic addition of hydroxyl groups to generate pentacoordinated phosphorus intermediates that rapidly decompose[14] This was supported by experimental evidence from in situ X-ray powder diffraction (XRPD), extended X-ray absorption fine structure (EXAFS), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) on MOFs based on Zr6O8 secondary building units interlinked by different organic ligands; sorption of nerve-agent Sarin simulant, dimethyl methylphosphonate (DMMP), leads to binding and decomposition into phosphonate products by the clusters, in particular, irreversibly bidentate-bound methyl methylphosphonate (MMPA)[11]. We show that it can be further applied for tracking reactive changes in these guest sub-structures
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
