title: Nonporous organic solids capable of dynamically resolving mixtures of diiodoperfluoroalkanes.
abstract: Halogen bonding has increasingly facilitated the assembly of diverse host-guest solids. Here, we show that a well-known class of organic salts, bis(trimethylammonium) alkane diiodides, can reversibly encapsulate alpha,omega-diiodoperfluoroalkanes (DIPFAs) through intermolecular interactions between the host's I- anions and the guest's terminal iodine substituents. The process is highly selective for the fluorocarbon that forms an I-...I(CF2)mI...I- superanion that is matched in length to the chosen dication. DIPFAs that are 2 to 12 carbons in length (common industrial intermediates) can thereby be isolated from mixtures by means of crystallization from solution upon addition of the dissolved size-matched ionic salt. The solid-state salts can also selectively capture the DIPFAs from the vapor phase, yielding the same product formed from solution despite a lack of porosity of the starting lattice structure. Heating liberates the DIPFAs and regenerates the original salt lattice, highlighting the practical potential for the system in separation applications.
authors.affiliation: Laboratory of Nanostructured Fluorinated Materials, Department of Chemistry, Materials, and Chemical Engineering Giulio Natta, Politecnico di Milano, via L. Mancinelli 7, 20131 Milan, Italy. pierangelo.metrangolo@polimi.it
authors.forename: Pierangelo
authors.initials: P
authors.lastname: Metrangolo
authors.forename: Yvan
authors.initials: Y
authors.lastname: Carcenac
authors.forename: Manu
authors.initials: M
authors.lastname: Lahtinen
authors.forename: Tullio
authors.initials: T
authors.lastname: Pilati
authors.forename: Kari
authors.initials: K
authors.lastname: Rissanen
authors.forename: Ashwani
authors.initials: A
authors.lastname: Vij
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Resnati