Light-induced stepped thermal relaxation in a Hofmann-type metal-organic framework  

作　　者：Wen Cui Wei-Wei Wu Ze-Yu Ruan Yan-Cong Chen Guang-Jun Zeng Guan-Xi Chen Si-Guo Wu Zhao-Ping Ni Ming-Liang Tong 

机构地区：[1]Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education,School of Chemistry,Institute of Green Chemistry and Molecular Engineering,Guangdong Basic Research Center of Excellence for Functional Molecular Engineering,Sun Yat-sen University,Guangzhou,510275,China

出　　处：《Science China Chemistry》2024年第6期1983-1989,共7页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(22271322,21821003);the National Key Research and Development Program of China(2018YFA0306001);the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(23ptpy73);Guangdong Special Fund for Science and Technology Innovation Strategy(pdjh2023b0019)。

摘　　要：Spin-crossover(SCO)materials with light-induced multistability have potential applications in multi-addressable opto-magnetic memory devices and multiple switches.Here,we reported a three-dimensional Hofmann-type metal-organic framework(MOF)[Fe(bpy){Pt(CN)_(4)}]·coumarin(1·coumarin,bpy=4,4′-bipyridine),which exhibits an incomplete and hysteretic SCO behavior.Most importantly,the light-induced stepped thermal relaxation(LISTR)with obvious magnetic plateau for a hidden intermediate spin state is firstly realized.This hidden spin state is also observed for the first time in the thermal relaxation after light-assisted spin state annealing(LASSA).Meanwhile,an extremely rare bi-directional light-induced excited spin-state trapping(LIESST)with the highest reverse-LIESST temperature is observed.Therefore,five spin states can be captured in 1·coumarin and the tristability can be modulated below 102 K through the excitation-relaxation mechanism.Hence,the light-and temperatureinduced multistability provides a new strategy for developing multistable materials.

关 键 词：LIGHT magnetic multistability IRON metal-organic framework SPIN-CROSSOVER 

分 类 号：TB34[一般工业技术—材料科学与工程]