title: Influence of Solvent-Like Sidechains on the Adsorption of Light Hydrocarbons in Metal-Organic Frameworks.
abstract: A variety of strategies have been developed to adsorb and separate light hydrocarbons in metal-organic frameworks. Here, we present a new approach in which the pores of a framework are lined with four different C3 sidechains that feature various degrees of branching and saturation. These pendant groups, which essentially mimic a low-density solvent with restricted degrees of freedom, offer tunable control of dispersive host-guest interactions. The performance of a series of frameworks of the type Zn2 (fu-bdc)2 (dabco) (fu-bdc(2-) =functionalized 1,4-benzenedicarboxylate; dabco=1,4-diazabicyclo[2.2.2]octane), which feature a pillared layer structure, were investigated for the adsorption and separation of methane, ethane, ethylene, and acetylene. The four frameworks exhibit low methane uptake, whereas C2 hydrocarbon uptake is substantially higher as a result of the enhanced interaction of these molecules with the ligand sidechains. Most significantly, the adsorption quantities and selectivity were found to depend strongly upon the type of sidechains attached to the framework scaffold.
authors.affiliation: Lehrstuhl für Anorganische Chemie II, Organometallics and Materials Chemistry, Ruhr-Universität Bochum, Universitätsstr. 150, 44801 Bochum (Germany).
authors.forename: Andreas
authors.initials: A
authors.lastname: Schneemann
authors.affiliation: Department of Chemistry, University of California, Berkeley, Berkeley 94720 California (USA).|Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge 02138 Massachusetts (USA).
authors.forename: Eric D
authors.initials: ED
authors.lastname: Bloch
authors.affiliation: Lehrstuhl für Anorganische Chemie II, Organometallics and Materials Chemistry, Ruhr-Universität Bochum, Universitätsstr. 150, 44801 Bochum (Germany).
authors.forename: Sebastian
authors.initials: S
authors.lastname: Henke
authors.affiliation: Aix-Marseille University, CNRS, MADIREL (UMR 7246), Centre Scientifique de St. Jérôme, 13397 Marseille cedex 20 (France).
authors.forename: Philip L
authors.initials: PL
authors.lastname: Llewellyn
authors.affiliation: Department of Chemistry, University of California, Berkeley, Berkeley 94720 California (USA). jrlong@berkeley.edu.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Long
authors.affiliation: Lehrstuhl für Anorganische Chemie II, Organometallics and Materials Chemistry, Ruhr-Universität Bochum, Universitätsstr. 150, 44801 Bochum (Germany). Roland.Fischer@rub.de.
authors.forename: Roland A
authors.initials: RA
authors.lastname: Fischer
keywords: host-guest systems; hydrocarbons; linker functionalization; metal-organic frameworks