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Chiral All-Nitrogen-Coordinated Dysprosium Single-Molecule Magnets
Chen Zhao1,2, Zhenhua Zhu1,3, Jinjiang Wu1,2
1State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry Chinese Academy of Sciences, Changchun, 130022, P. R. China.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|November 3, 2022
Summary
Chiral dinuclear dysprosium(III) macrocycles were synthesized. Complex 2R/2S exhibits single-molecule magnet behavior, representing the first homochiral all-nitrogen-coordinated lanthanide single-molecule magnet.
Area of Science:
- Coordination Chemistry
- Materials Science
- Magnetochemistry
Background:
- Lanthanide complexes are investigated for single-molecule magnet (SMM) properties.
- Chiral ligands are crucial for developing homochiral SMMs.
- Azido-bridged dinuclear structures offer unique magnetic interactions.
Purpose of the Study:
- To construct chiral end-on azido-bridged dinuclear hexaazamacrocycles containing Dy(III) ions.
- To investigate the impact of ligand structure and coordination environment on magnetic properties.
- To explore the potential of these complexes as homochiral single-molecule magnets.
Main Methods:
- Synthesis of two pairs of chiral dinuclear Dy(III) complexes ([Dy2(L^N6_R/S)2(N3)2Cl2](BPh4)2 (1R/1S) and [Dy2(L^N6_R/S)2(N3)4]Cl2 (2R/2S)).
- Structural characterization using X-ray crystallography, revealing nine-coordinate Dy(III) centers with hula-loop geometry.
- Magnetic studies, including variable-temperature magnetic susceptibility and magnetization measurements.
Main Results:
- Complex 2S demonstrated typical single-molecule magnet (SMM) behavior under a zero dc field.
- Complex 1S exhibited slow relaxation of magnetization due to a weaker axial crystal field.
- Complex 2R/2S is identified as the first homochiral all-nitrogen-coordinated lanthanide single-molecule magnet.
Conclusions:
- The synthetic strategy allows for tuning the coordination environment and magnetic properties of Dy(III) complexes.
- Homochiral all-nitrogen coordination in lanthanide complexes can lead to effective SMM behavior.
- These findings open new avenues for designing chiral lanthanide-based magnetic materials.
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