Responsive Four-Coordinate Iron(II) Nodes in FePd(CN)4

Ryo Ohtani; Hiromu Matsunari; Takafumi Yamamoto; Koji Kimoto; Masaaki Isobe; Kotaro Fujii; Masatomo Yashima; Susumu Fujii; Akihide Kuwabara; Yuh Hijikata; Shin-Ichiro Noro; Masaaki Ohba; Hiroshi Kageyama; Shinya Hayami

doi:10.1002/anie.202008187

Responsive Four-Coordinate Iron(II) Nodes in FePd(CN)₄

Angew Chem Int Ed Engl. 2020 Oct 19;59(43):19254-19259. doi: 10.1002/anie.202008187. Epub 2020 Aug 24.

Authors

Ryo Ohtani¹, Hiromu Matsunari², Takafumi Yamamoto³, Koji Kimoto⁴, Masaaki Isobe⁵, Kotaro Fujii⁶, Masatomo Yashima⁶, Susumu Fujii^{7

8}, Akihide Kuwabara^{7

8}, Yuh Hijikata⁹, Shin-Ichiro Noro¹⁰, Masaaki Ohba¹, Hiroshi Kageyama¹¹, Shinya Hayami²

Affiliations

¹ Department of Chemistry, Faculty of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
² Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto, 860-8555, Japan.
³ Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama, 226-8503, Japan.
⁴ Research Center for Advanced Measurement and Characterization, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan.
⁵ Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan.
⁶ Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1-W4-17, O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.
⁷ Nanostructures Research Laboratory, Japan Fine Ceramics Center, 2-4-1 Mutsuno, Atsuta, Nagoya, 456-8587, Japan.
⁸ Center for Materials Research by Information Integration, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan.
⁹ Institute for Chemical Reaction Design and Discovery, (WPI-ICReDD), Hokkaido University, Sapporo, 001-0021, Japan.
¹⁰ Faculty of Environmental Earth Science, Hokkaido University, Sapporo, 060-0810, Japan.
¹¹ Graduate School of Engineering, Kyoto University, Kyoto, 615-8510, Japan.

PMID: 32662185
DOI: 10.1002/anie.202008187

Abstract

Metal node design is crucial for obtaining structurally diverse coordination polymers (CPs) and metal-organic frameworks with desirable properties; however, Fe^II ions are exclusively six-coordinated. Herein, we present a cyanide-bridged three-dimensional (3D) CP, FePd(CN)₄ , bearing four-coordinate Fe^II ions, which is synthesized by thermal treatment of a two-dimensional (2D) six-coordinate Fe^II CP, Fe(H₂ O)₂ Pd(CN)₄ ⋅4 H₂ O, to remove water molecules. Atomic-resolution transmission electron microscopy and powder X-ray and neutron diffraction measurements revealed that the FePd(CN)₄ structure is composed of a two-fold interpenetrated PtS topology network, where the Fe^II center demonstrates an intermediate geometry between tetrahedral and square-planar coordination. This four-coordinate Fe^II center with the distorted geometry can act as a thermo-responsive flexible node in the PtS network.

Keywords: coordination polymers; cyanide; four-coordination; iron; thermal expansion.

Abstract

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