Reactive Chlorine Capture by Dichlorination of Alkene Linkers in Metal-Organic Frameworks.

Chlorine (Cl) is a toxic and corrosive gas that is both an essential reagent in industry and a potent chemical warfare agent. Materials that can strongly bind Cl at low pressures are essential for industrial and civilian personal protective equipment (PPE). Herein, we report the first examples of irreversible Cl capture via the dichlorination of alkene linkages in Zr-based metal-organic frameworks. Frameworks constructed from fumarate (Zr-fum) and stilbene (Zr-stilbene) linkers retain long-range order and accessible porosity after alkene dichlorination. In addition, energy-dispersive X-ray spectroscopy reveals an even distribution of Cl throughout both materials after Cl capture. Cl uptake experiments reveal high irreversible uptake of Cl (>10 wt %) at low partial pressures (<100 mbar), particularly in Zr-fum. In contrast, traditional porous carbons mostly display reversible Cl capture, representing a continued risk to users after exposure. Overall, our results support that alkene dichlorination represents a new pathway for reactive Cl capture, opening new opportunities for binding this gas irreversibly in PPE.