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

Chlorine (Cl ₂ ) 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 ₂ at low pressures are essential for industrial and civilian personal protective equipment (PPE). Herein, we report the first examples of irreversible Cl ₂ 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 ₂ capture. Cl ₂ uptake experiments reveal high irreversible uptake of Cl ₂ (>10 wt %) at low partial pressures (<100 mbar), particularly in Zr-fum. In contrast, traditional porous carbons mostly display reversible Cl ₂ capture, representing a continued risk to users after exposure. Overall, our results support that alkene dichlorination represents a new pathway for reactive Cl ₂ capture, opening new opportunities for binding this gas irreversibly in PPE.