Multi-step spin-crossover in a 2D Hofmann-type clathrate with bisubstituted pyrazine
Xiangkun Wen1, Mengling Wu1, Yancong Chen1
1Key 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. nizhp@mail.sysu.edu.cn.
Dalton Transactions (Cambridge, England : 2003)
|July 21, 2025
Summary
Researchers developed new multi-step spin-crossover (SCO) materials using an inexpensive asymmetric ligand. These novel 2D Hofmann-type clathrates show potential for advanced data storage and multiple switching applications.
Area of Science:
- Materials Science
- Coordination Chemistry
- Solid-State Chemistry
Background:
- Multi-step spin-crossover (SCO) materials are crucial for high-order data storage and multiple switches.
- The scarcity of such materials necessitates novel design strategies.
- Two-dimensional (2D) Hofmann-type clathrates offer a promising structural framework.
Purpose of the Study:
- To design and synthesize novel 2D Hofmann-type clathrates exhibiting multi-step SCO behavior.
- To investigate the influence of asymmetric ligands on SCO properties.
- To explore cost-effective strategies for developing advanced SCO materials.
Main Methods:
- Synthesis of 2D Hofmann-type clathrates using an asymmetric ligand, 2-chloro-6-methylpyrazine (ClMepz).
- Characterization of compounds [Fe(ClMepz)2{M(CN)2}2]·ClMepz (M = Au (1), Ag (2)).
- Magneto-structural analysis to understand spin-state transitions and interactions.
Main Results:
- Compound 1 ([Fe(ClMepz)2{Au(CN)2}2]·ClMepz) exhibited multi-step SCO behavior with more spin states than compound 2.
- The linear [Au(CN)2]- unit induced greater stress and antiferro-elastic interactions in the Hofmann layer.
- Asymmetric host-guest interactions were identified as a key factor in achieving stepwise SCO properties.
Conclusions:
- The incorporation of asymmetric bisubstituted ligands into 2D Hofmann-type systems is a viable strategy for developing multi-step SCO materials.
- This approach offers a cost-effective route to advanced materials for data storage and switching.
- The study highlights the importance of ligand design in controlling SCO behavior.
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