Multichannel Magnetic Switching Observed in a Fe(II) Spin-Crossover Compound Bearing Rotatable Ligands.

Inorg Chem

Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China.

Published: June 2025


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Article Abstract

The magnetic properties of materials can be modulated by external stimuli through either spin-state transition or modification of the coordination environment. However, achieving both mechanisms in a single-phase system via sophisticated molecular design remains a formidable challenge. In this work, we present an Fe(II) spin-crossover (SCO) complex incorporating rotatable isoxazole ligands, which exhibits a three-step reversible magnetic transition from 120 to 300 K. In this compound, the metal centers experience two-step SCO transition at ca. 147 and 221 K. Upon further heating, the isoxazole ligands undergo significant rotation around the Fe-N coordination bonds, accompanied by an order-disorder phase transition of the ClO counteranions. As the rotation of organic ligand can influence the electron-density delocalization between the aromatic ring and Fe ion, an additional magnetic anomaly arises near 245 K. The use of rotatable ligands to build SCO compounds offers a promising avenue toward superior materials capable of integrating switchable properties that stem from both electronic-state transition and molecular structural changes.

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http://dx.doi.org/10.1021/acs.inorgchem.5c01241DOI Listing

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