Responsive Four‐Coordinate Iron(II) Nodes in FePd(CN)4. Issue 43 (24th August 2020)

• Record Type: Journal Article
• Authors: Ohtani, Ryo; Matsunari, Hiromu; Yamamoto, Takafumi; Kimoto, Koji; Isobe, Masaaki; Fujii, Kotaro; Yashima, Masatomo; Fujii, Susumu; Kuwabara, Akihide; Hijikata, Yuh; Noro, Shin‐ichiro; Ohba, Masaaki; Kageyama, Hiroshi; Hayami, Shinya
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 43(2020)
• Page Start: 19254
• Page End: 19259
• Publication Date: 2020-08-24
• Subjects: coordination polymers -- cyanide -- four-coordination -- iron -- thermal expansion; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202008187
• Languages: English
• ISSNs: 1433-7851

Abstract

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. Abstract : A cyanide‐bridged coordination polymer (FePd(CN)4 ) consists of responsive four‐coordinate Fe II centers. The Fe II nodes flexibly change the distorted coordination geometry of the polymer, inducing an unusually large anisotropic thermal expansion of the PtS‐type framework.