Radical-Bridged Heterometallic Single-Molecule Magnets Incorporating Four Lanthanoceniums

Peng Zhang; Qian-Cheng Luo; Zhenhua Zhu; Wanrong He; Nan Song; Junting Lv; Xuning Wang; Quan-Guo Zhai; Yan-Zhen Zheng; Jinkui Tang

doi:10.1002/anie.202218540

Radical-Bridged Heterometallic Single-Molecule Magnets Incorporating Four Lanthanoceniums

Angew Chem Int Ed Engl. 2023 Mar 13;62(12):e202218540. doi: 10.1002/anie.202218540. Epub 2023 Feb 14.

Authors

Affiliations

¹ School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China.
² Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University Xi An Shi, Xi'an, 710054, China.
³ State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.

PMID: 36710242
DOI: 10.1002/anie.202218540

Abstract

The syntheses and magnetic properties of organometallic heterometallic compounds [K(THF)₆ ]{Co^I [(μ₃ -HAN)RE₂ Cp*₄ ]₂ } (1-RE) and [K(Crypt)]₂ {Co^I [(μ₃ -HAN)RE₂ Cp*₄ ]₂ } (2-RE) containing hexaazatrinaphthylene radicals (HAN⋅^3- ) and four rare earth (RE) ions are reported. 1-RE shows isolable species with ligand-based mixed valency as revealed by cyclic voltammetry (CV) thus leading to the isolation of 2-RE via one-electron chemical reduction. Strong electronic communication in mixed-valency supports stronger overall ferromagnetic behaviors in 2-RE than 1-RE containing Gd and Dy ions. Ac magnetic susceptibility data reveal 1-Dy and 2-Dy both exhibit slow magnetic relaxation. Importantly, larger coercive field was observed in the hysteresis of 2-Dy at 2.0 K, indicating the enhanced SMM behavior compared with 1-Dy. Ligand-based mixed-valency strategy has been used for the first time to improve the magnetic coupling in lanthanide (Ln) SMMs, thus opening up new ways to construct strongly coupled Ln-SMMs.

Keywords: Heterometallic; Lanthanide; Mixed Valence; Radical Bridge; Single Molecule Magnets.

Abstract

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