Relationship between spin transition temperature and thermal relaxation temperature from light-induced excited high spin phase on mononuclear complexes having linear hexadentate ligand

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K14240
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 34010:Inorganic/coordination chemistry-related
• Research Institution: Gifu University
• Principal Investigator: Hagiwara Hiroaki 岐阜大学, 教育学部, 准教授 (20706973)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: スピンクロスオーバー / LIESST / 熱緩和 / 光応答 / 光スイッチング / 直鎖型配位子 / 1,2,3-トリアゾール / 金属錯体

Outline of Final Research Achievements

In this study, we synthesized various spin crossover (SCO) iron(II) complexes having 1,2,3-triazole-containing linear hexadentate ligand and investigated their spin transition temperature (T1/2) and thermal relaxation temperature （T(LIESST)）after light-induced excited spin-state trapping (LIESST). The T0 value of the linear hexadentate ligand system estimated by using the linear correlation T(LIESST) = T0-0.3T1/2 is 189 K and is higher than those of other SCO system having mono-, bi-, tri-, and tetradentate ligands. We also synthesized related SCO iron(II) compounds having tripodal hexadentate ligand or linear pentadentate ligand and compared their SCO properties with those of the linear hexadentate ligand system.

Free Research Field

錯体化学

Academic Significance and Societal Importance of the Research Achievements

次世代メモリー素子, スイッチング素子の候補物質として, 温度変化や光照射により磁気的スイッチングを示すスピンクロスオーバー（SCO）錯体が挙げられるが, それらのデバイスへの応用には室温付近での光による物性制御が不可欠となる。本研究の成果は, 低温下で光により誘起された準安定HS状態をより高温まで保持するための分子設計指針を提案しており, 今後の物質開発の一助になることが期待される。