title: Crystalline coordination framework endowed with dynamic gate-opening behaviour by being downsized to a thin film.
abstract: The fabrication of porous coordination frameworks in thin-film forms has been investigated intensively with a view to using their structural response to external stimuli and guests for potential nanotechnological applications, for example as membranes for gas separation. Here we report a coordination framework that exhibits a dynamic guest-sorption behaviour in a nanometre-sized thin-film form (16 nm thick), yet shows no guest uptake in the bulk. Highly oriented crystalline thin films of this coordination framework--which consists of interdigitated two-dimensional layers of {Fe(py)2[Pt(CN)4]} (py, pyridine)--were fabricated through liquid-phase layer-by-layer synthesis. The resulting thin film exhibited a clear guest uptake with a structural transformation of the gate-opening type as characterized by in situ X-ray diffraction. Increasing the film's thickness markedly suppressed this behaviour. We envisage that such a crystal-downsizing effect may be observed with other coordination frameworks, and may be of use to develop functional materials, for example, for switching or sensing devices.
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Shun
authors.initials: S
authors.lastname: Sakaida
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Chiyoda-ku, Tokyo 102-0075, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Otsubo
authors.affiliation: Synchrotron X-ray Station at SPring-8, National Institute for Materials Science (NIMS), 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Osami
authors.initials: O
authors.lastname: Sakata
authors.affiliation: Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan.
authors.forename: Chulho
authors.initials: C
authors.lastname: Song
authors.affiliation: Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan.
authors.forename: Akihiko
authors.identifier: http://orcid.org/0000-0002-1319-388X
authors.initials: A
authors.lastname: Fujiwara
authors.affiliation: Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan.|RIKEN SPring-8 Center, Kouto 1-1-1, Sayo, Hyogo 679-5148, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takata
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Chiyoda-ku, Tokyo 102-0075, Japan.|Institute for Integrated Cell-Material Science (iCeMS), Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.|INAMORI Frontier Research Center, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-3095, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitagawa