title: Investigating H₂ Sorption in a Fluorinated Metal-Organic Framework with Small Pores Through Molecular Simulation and Inelastic Neutron Scattering.
abstract: Simulations of H2 sorption were performed in a metal-organic framework (MOF) consisting of Zn(2+) ions coordinated to 1,2,4-triazole and tetrafluoroterephthalate ligands (denoted [Zn(trz)(tftph)] in this work). The simulated H2 sorption isotherms reported in this work are consistent with the experimental data for the state points considered. The experimental H2 isosteric heat of adsorption (Qst) values for this MOF are approximately 8.0 kJ mol(-1) for the considered loading range, which is in the proximity of those determined from simulation. The experimental inelastic neutron scattering (INS) spectra for H2 in [Zn(trz)(tftph)] reveal at least two peaks that occur at low energies, which corresponds to high barriers to rotation for the respective sites. The most favorable sorption site in the MOF was identified from the simulations as sorption in the vicinity of a metal-coordinated H2O molecule, an exposed fluorine atom, and a carboxylate oxygen atom in a confined region in the framework. Secondary sorption was observed between the fluorine atoms of adjacent tetrafluoroterephthalate ligands. The H2 molecule at the primary sorption site in [Zn(trz)(tftph)] exhibits a rotational barrier that exceeds that for most neutral MOFs with open-metal sites according to an empirical phenomenological model, and this was further validated by calculating the rotational potential energy surface for H2 at this site.
authors.affiliation: †Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, CHE205, Tampa, Florida 33620-5250, United States.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Forrest
authors.affiliation: †Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, CHE205, Tampa, Florida 33620-5250, United States.
authors.forename: Tony
authors.initials: T
authors.lastname: Pham
authors.affiliation: ‡Department of Structural Chemistry, University of Milan, 21 Via G. Venezian, I-20133 Milan, Italy.|§Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier Blvd., Sofia 1164, Bulgaria.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Georgiev
authors.affiliation: ⊥UFR Sciences et Technologies, Université Blaise Pascal, Clermont-Ferrand, 24 Avenue des Landais, 63170 Aubière, France.
authors.forename: Florian
authors.initials: F
authors.lastname: Pinzan
authors.affiliation: †Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, CHE205, Tampa, Florida 33620-5250, United States.
authors.forename: Christian R
authors.initials: CR
authors.lastname: Cioce
authors.affiliation: ¶Physik Department, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 3, 91058 Erlangen, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Unruh
authors.affiliation: †Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, CHE205, Tampa, Florida 33620-5250, United States.
authors.forename: Juergen
authors.initials: J
authors.lastname: Eckert
authors.affiliation: †Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, CHE205, Tampa, Florida 33620-5250, United States.
authors.forename: Brian
authors.initials: B
authors.lastname: Space