title: Development of Ion-Conductive and Vapoluminescent Porous Coordination Polymers Composed of Ruthenium(II) Metalloligand.
abstract: We synthesized two new porous coordination polymers (PCPs) {Ln7(OH)5[Ru(dcbpy)3]4·4nH2O} (Ln7-Ru4; Ln = Ce, Nd) composed of the luminescent ruthenium(II) metalloligand [Ru(4,4'-dcbpy)3]4-([4Ru]; 4,4'-dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) and lanthanide ions Ln3+(Ln = Ce, Nd). These two PCPs Ln7-Ru4are isomorphous with the previously reported PCP La7-Ru4, and the lattice constants (a, c, and unit cell volume V) changed systematically according to the lanthanide contraction. All three Ln7-Ru4compounds have OH-anion containing porous structures and a large number of hydrate water molecules within the pores, resulting in moderate ion conductivities (10-6-10-7S cm-1) at 90% relative humidity (RH) and 298 K. In contrast, the structural transformation of Ln7-Ru4associated with water-vapor adsorption/desorption strongly depends on the lanthanide ion; the Ln7-Ru4compounds with larger Ln3+ions recover the original porous structure at lower relative humidities (RH). A similar trend was observed for the ion conduction activation energy, suggesting that the bridging Ln3+ion plays an important role in the formation of the ion-conductive pathways. La7-Ru4and Ce7-Ru4exhibit vapochromic luminescence associated with water vapor adsorption/desorption, arising from the3MLCT emission of [4Ru]. This vapochromic behavior is also affected by the replacement of the Ln3+ion; the vapochromic shift of Ce7-Ru4was observed at RH values (near 100% RH) higher than that of La7-Ru4.3MLCT emissions of the [4Ru] metalloligand in Nd7-Ru4were barely observable in the visible region, but sharp emission bands characteristic of 4f-4f transitions of the Nd3+ion were observed in the near-infrared (NIR) region (arising from the1MLCT transition of [4Ru]), suggesting the transfer of energy from the [4Ru]3MLCT excited state to the 4f-4f transition state of the Nd3+ions.
authors.affiliation: Department of Chemistry, Faculty of Science, Hokkaido University , North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Watanabe
authors.affiliation: Department of Chemistry, Faculty of Science, Hokkaido University , North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.|Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST) , Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Atsushi
authors.identifier: http://orcid.org/0000-0002-1937-7698
authors.initials: A
authors.lastname: Kobayashi
authors.affiliation: Department of Chemistry, Faculty of Science, Hokkaido University , North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
authors.forename: Erika
authors.initials: E
authors.lastname: Saitoh
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology , 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Nagao
authors.affiliation: Graduate School of Engineering, Hokkaido University , North-13 West-8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors.forename: Shun
authors.initials: S
authors.lastname: Omagari
authors.affiliation: Graduate School of Engineering, Hokkaido University , North-13 West-8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakanishi
authors.affiliation: Graduate School of Engineering, Hokkaido University , North-13 West-8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors.forename: Yasuchika
authors.initials: Y
authors.lastname: Hasegawa
authors.affiliation: Department of Chemistry, Faculty of Science, Hokkaido University , North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
authors.forename: W M C
authors.identifier: http://orcid.org/0000-0003-0213-0688
authors.initials: WM
authors.lastname: Sameera
authors.affiliation: Department of Chemistry, Faculty of Science, Hokkaido University , North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Department of Chemistry, Faculty of Science, Hokkaido University , North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Kato