Study on magnetic materials showing drastic spin state transition upon relatively small structural transformation

2018 Fiscal Year Final Research Report

• Project/Area Number: 15H03793
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Functional solid state chemistry
• Research Institution: The University of Electro-Communications
• Principal Investigator: Ishida Takayuki 電気通信大学, 大学院情報理工学研究科, 教授 (00232306)
• Research Collaborator: Kogane Tamizo 電気通信大学 ; Okazawa Atsushi 東京大学 ; Kanetomo Takuya 東京理科大学
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 分子性磁性体 / 集積型金属錯体 / 超分子科学 / 単分子磁石 / 高スピン分子 / 相転移

Outline of Final Research Achievements

Solid-state magnetic switches are of increasing interest for future application to sensing, memory, display, etc. The authors and co-workers have developed unconventional spin transition/crossover materials, where the sense of organic chemistry has competently been adopted. The first example is a supramolecular chemistry of genuine organic nitroxide biradicals with a triplet ground state, which undergo stepwise polymerization/depolymerization in a crystal. The second example belongs to 2p-3d heterospin systems where the nitroxide-nickel(II) or -copper(II) bond rotates and switches exchange coupling. As these examples show, single-crystal-to-single-crystal structural transitions are often recorded, thanks to small atomic dislocation. Molecular motion in crystalline solids is observed more frequently than expected. Attentive crystallographic study affords sure proof for the spin transition phenomenon.

Free Research Field

有機材料科学

Academic Significance and Societal Importance of the Research Achievements

分子磁性という学問分野は我国が世界に誇れる基幹物理化学の一つである。この分野発の新規材料群で、学界・産業界に貢献することは重要である。本研究推進においては、Dalton Trans. 誌の内表紙採用(2016)、Bull. Chem. Soc.Jpn. 誌のBCSJ Award受賞と表紙採用(2016)、Inorg. Chem. 誌で Editors' Choice (2017)、New J. Chem. 誌で裏表紙採用(2019), および印刷中ながら Org. Lett. 誌で内表紙採用(2019) などのように、外部評価も概して高い。学術上の意義を反映していると考えられる。