title: Proton conductivity control by ion substitution in a highly proton-conductive metal-organic framework.
abstract: Proton conductivity through two-dimensional (2-D) hydrogen-bonding networks within a layered metal-organic framework (MOF) (NH4)2(H2adp)[Zn2(ox)3]·3H2O (H2adp = adipic acid; ox = oxalate) has been successfully controlled by cation substitution. We synthesized a cation-substituted MOF, K2(H2adp)[Zn2(ox)3]·3H2O, where the ammonium ions in a well-defined hydrogen-bonding network are substituted with non-hydrogen-bonding potassium ions, without any apparent change in the crystal structure. We successfully controlled the proton conductivity by cleavage of the hydrogen bonds in a proton-conducting pathway, showing that the 2-D hydrogen-bonding networks in the MOF truly contribute to the high proton conductivity. This is the first example of the control of proton conductivity by ion substitution in a well-defined hydrogen-bonding network within a MOF.
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University , Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Sadakiyo
authors.forename: Teppei
authors.initials: T
authors.lastname: Yamada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitagawa
mesh_terms: D000272:Adipates / Q000737:chemistry; D064751:Ammonium Compounds / Q000737:chemistry; D002412:Cations / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry*; D010070:Oxalates / Q000737:chemistry; D011188:Potassium / Q000737:chemistry; D011522:Protons
chemical_list: D000272:Adipates; D064751:Ammonium Compounds; D002412:Cations; D009942:Organometallic Compounds; D010070:Oxalates; D011522:Protons; C029900:adipic acid; D011188:Potassium