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Two-Coordinate Co(II) Imido Complexes as Outstanding Single-Molecule Magnets
Xiao-Nan Yao1, Jing-Zhen Du2, Yi-Quan Zhang3
1Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, PR China.
New cobalt imido complexes achieve record-breaking performance as single-molecule magnets (SMMs). These molecules exhibit slow magnetization relaxation, paving the way for advanced molecular magnetism applications.
Area of Science:
- Molecular Magnetism
- Coordination Chemistry
- Quantum Materials
Background:
- The development of single-molecule magnets (SMMs) with enhanced magnetic anisotropy is crucial for advancing molecular magnetism.
- High-performance SMMs require novel molecular designs that increase magnetic anisotropy.
Purpose of the Study:
- To design and synthesize novel two-coordinate cobalt imido complexes for high-performance SMM applications.
- To investigate the origin of large magnetic anisotropy in these cobalt complexes.
Main Methods:
- Synthesis of two-coordinate cobalt imido complexes.
- Magnetization relaxation measurements under zero direct-current field.
- Theoretical investigations using single-ion and Co-N coupling models.
Main Results:
- The reported cobalt imido complexes exhibit slow relaxation of magnetization at zero field.
- A record high effective relaxation barrier of 413 cm-1 was achieved for transition metal-based SMMs.
- Theoretical models elucidated the role of the pseudo-linear ligand field and strong Co-N ferromagnetic interaction in enhancing magnetic anisotropy.
Conclusions:
- Two-coordinate cobalt imido complexes represent a promising platform for high-performance SMMs.
- The inherent large magnetic anisotropy of the [CoN]+ core, particularly the |MJ = ± 7/2⟩ ground Kramers doublet, is key to their SMM behavior.
- This work sets a new benchmark for transition metal-based SMMs and guides future molecular design.
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