title: Guest-Induced Two-Way Structural Transformation in a Layered Metal-Organic Framework Thin Film.
abstract: Fabrication of thin films made of metal-organic frameworks (MOFs) has been intensively pursued for practical applications that use the structural response of MOFs. However, to date, only physisorption-induced structural response has been studied in these films. Chemisorption can be expected to provide a remarkable structural response because of the formation of bonds between guest molecules and reactive metal sites in host MOFs. Here, we report that chemisorption-induced two-way structural transformation in a nanometer-sized MOF thin film. We prepared a two-dimensional layered-type MOF Fe[Pt(CN)4] thin film using a step-by-step approach. Although the as-synthesized film showed poor crystallinity, the dehydrated form of this thin film had a highly oriented crystalline nature (Film-D) as confirmed by synchrotron X-ray diffraction (XRD). Surprisingly, under water and pyridine vapors, Film-D showed chemisorption-induced dynamic structural transformations to Fe(L)2[Pt(CN)4] thin films [L = H2O (Film-H), pyridine (Film-P)], where water and pyridine coordinated to the open Fe2+site. Dynamic structural transformations were also confirmed by in situ XRD, sorption measurement, and infrared reflection absorption spectroscopy. This is the first report of chemisorption-induced dynamic structural response in a MOF thin film, and it provides useful insights, which would lead to future practical applications of MOFs utilizing chemisorption-induced structural responses.
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University , Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Haraguchi
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University , Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, 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-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Osami
authors.initials: O
authors.lastname: Sakata
authors.affiliation: School of Science and Technology, Kwansei Gakuin University , 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.
authors.forename: Akihiko
authors.identifier: 0000-0002-1319-388X
authors.initials: A
authors.lastname: Fujiwara
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University , Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.|Institute for Integrated Cell-Material Sciences (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.identifier: 0000-0001-6955-3015
authors.initials: H
authors.lastname: Kitagawa