【公開日：2024.07.25】【最終更新日：2024.06.17】

課題データ / Project Data

課題番号 / Project Issue Number

23UT0184

利用課題名 / Title

Crystal Structure Determination on Various Molecule-Based Magnets

利用した実施機関 / Support Institute

東京大学 / Tokyo Univ.

機関外・機関内の利用 / External or Internal Use

外部利用/External Use

技術領域 / Technology Area

【横断技術領域 / Cross-Technology Area】（主 / Main）計測・分析/Advanced Characterization（副 / Sub）-

【重要技術領域 / Important Technology Area】（主 / Main）量子・電子制御により革新的な機能を発現するマテリアル/Materials using quantum and electronic control to perform innovative functions（副 / Sub）-

キーワード / Keywords

スピン制御/ Spin control,X線回折/ X-ray diffraction

利用者と利用形態 / User and Support Type

利用者名（課題申請者）/ User Name (Project Applicant)

Wang Junhao

所属名 / Affiliation

筑波大学　大学院数理物質系物質工学域

共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes

長島 俊太郎,赤木 慎太郎,KUMAR KUNAL,小林 大輝

ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes

飯盛 桂子

利用形態 / Support Type

（主 / Main）機器利用/Equipment Utilization（副 / Sub）-

利用した主な設備 / Equipment Used in This Project

UT-201：無機微小結晶構造解析装置

報告書データ / Report

概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)

Aim: In this project, we used single-crystal X-ray diffractometer (RIGAKU VariMax Dual) to re-determine a crystal structures of our synthesized compound. Use Application: The structure result was used for interpretate the magnetic properties of the compound. Contents: We measured the crystal structure of a two-dimensional cyanido-bridged coordination network, [Ni^II(pz)₄]{[Ni^II(pz)₃][W^V(CN)₈]}₂·3.5H₂O (NiW pz = pyrazole), showing metamagnetic behavior

実験 / Experimental

The analysis of NiW's single-crystal X-ray diffraction (XRD) was performed using a RIGAKU VariMax Dual diffractometer with Rigaku Saturn Kappa CCD detector coupled with a MicroMax-007 HF/Varimax rotating-anode X-ray source emitting monochromatic MoKα radiation. A crystal was prepared with Apiezon N grease and placed on a Micro Mounts holder for measurement at roughly 90 K. The collected diffraction frames were processed by CrisAlisPro software from Rigaku. The crystal's structure was deduced through the direct methods of the SHELXS-97 program and further refined by full-matrix least squares on F² using SHELX-2014/7. Additionally, Olex-2 1.3 software was utilized for further refinement and resolution of structures. The disorder in the pyrazole ligands necessitated the use of the PART command and additional restraints like FLAT, DFIX, and ISOR for satisfactory refinement. Anisotropic refinement was applied to all non-hydrogen atoms. The NiW crystallographic data has been stored in the CCDC database under the accession number 2250632.

結果と考察 / Results and Discussion

This analysis determined that NiW has an orthorhombic Pbcn space group, with lattice constants a = 29.0676(9) Å, b = 10.4430(3) Å, and c = 20.7787(7) Å. The structure features sinuous layers connected by cyanide that are interspersed with water molecules. Within the asymmetric unit, it was observed that the layers are composed of a unique [W^V(CN)₈] entity with a skewed dodecahedral coordination structure. There are two different Ni^II sites: Ni1, which binds with four pz ligands and two cyanide bridges resulting in a [Ni1^II(pz)₄(CN)₂] complex, and Ni2, which connects with three pz ligands and three cyanide bridges to form a [Ni2^II(pz)₃(CN)₃] complex. These Ni and W units are then polymerized through the cyanide bridges to create undulating layers that spread along the ab plane of the crystal. From the perspective of the c-axis, this coordination forms a ladder-like pattern with two different square sizes within the layers: a smaller square made of two Ni2 and two W1 atoms, and a larger one composed of two Ni1 atoms, two Ni2 atoms, and four W1 atoms. Thus, the smaller and larger ladders consist of squares of varying dimensions. The peaks and valleys of the wavy layers are defined by the smaller four-membered square ladders, while the wave slopes are defined by the larger eight-membered square ladders; these ladders share edges of the {[Ni^II(pz)₃][W^V(CN)₈]}_n chain along the b-axis.Such layered coordination structure explains the unique magnetic behavior of NiW, interlayer antiferromagnetic and intralayer ferromagnetic interactions.

図・表・数式 / Figures, Tables and Equations

Side view of the layers of NiW together with the interlayer and intralayer magnetic interaction diagram. Super-exchange interactions between Ni and W within the two-dimensional layer are ferromagnetic ( J > 0), whereas the magnetic interaction between layers are antiferromagnetic (J < 0) at low magnetic field.

その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)

成果発表・成果利用 / Publication and Patents

論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)

1. Shintaro Akagi, A Ni^II–W^V(CN)₈ layer magnet showing metamagnetic behavior, Pure and Applied Chemistry, 95, 701-705(2023).
   DOI: 10.1515/pac-2023-0303
   

口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.

1. Shintaro Akagi, Junhao Wang, Kenta Imoto, Kunal Kumar, Shin-ichi Ohkoshi, Hiroko Tokoro, “Metamagnetism in Two Nickel-Octacyanidotungstate Complexes” 錯体化学会 第73回討論会, 2023 September 21st.
2. 赤木 慎太郎, Junhao Wang, 井元 健太, Kunal Kumar, 大越 慎一, 所 裕子, “ニッケルーオクタシアノタングステン２次元錯体におけるメタ磁性” 日本化学会 第104春季年会, 2024年3月21日

特許 / Patents

特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件