Adsorption of polyhaloalkane vapors by adaptive macrocycle crystals of WreathArene through C-halogen⋯π interactions

Polyhaloalkanes are broadly useful yet environmentally harmful stock chemicals, therefore the development of adsorbent materials with capacity and selectivity for polyhaloalkane vapors is highly desirable. Here we report a novel macrocycle WreathArene, a fluorinated C3-symmetrical [16]-paracyclophane. In the crysalline state, WreathArene features guest-adaptive polymorphism for polyhaloalkanes including chloroform, tribromomethane, 1,1,2-trichloroethane, and 1,2-dibromoethane. Non-covalent C-halogen⋯π interactions are observed in all of these host-guest structures. Based on these properties, the activated WreathArene crystals can be utilized as a selective and recyclable adsorbent for polyhaloalkane vapors with excellent capacity under user-friendly conditions.