title: Spectroscopic evidence for the influence of the benzene sites on tightly bound H2 in metal-organic frameworks with unsaturated metal centers: MOF-74-cobalt.
abstract: The role of low binding energy sites on the adsorption of H(2) in metal-organic frameworks (MOFs) with unsaturated metal centers has not been identified. For instance, the importance of the benzene sites on H(2) adsorption at the metal site in MOF-74 has not been established. We report here experimental evidence that unambiguously shows that the internal mode of H(2) adsorbed at the metal site undergoes both a frequency shift and a marked change in its dynamic dipole moment when H(2) is adsorbed at the next nearest neighbor "benzene" site in MOF-74-Co. The effect of loading (i.e., occupation of all benzene sites) also induces spectroscopic shifts in H(2) at the metal site. These interactions highlight the role of lower binding energy sites in H(2) adsorption.
authors.affiliation: Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080, USA.
authors.forename: Nour
authors.initials: N
authors.lastname: Nijem
authors.forename: Lingzhu
authors.initials: L
authors.lastname: Kong
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Zhao
authors.forename: Haohan
authors.initials: H
authors.lastname: Wu
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: David C
authors.initials: DC
authors.lastname: Langreth
authors.forename: Yves J
authors.initials: YJ
authors.lastname: Chabal
mesh_terms: D000327:Adsorption; D001555:Benzene Derivatives / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001555:Benzene Derivatives; D009942:Organometallic Compounds; D003035:Cobalt; D006859:Hydrogen