Using Diffusely Charged Bridging Ligands to Maximize Single-Ion Anisotropy and Dipolar Coupling in Dinuclear ErCOT...

Area of Science:

• Molecular Magnetism
• Coordination Chemistry
• Quantum Magnetism

Background:

• Developing high-dimensional molecular magnets requires balancing magnetic anisotropy and long-range magnetic cooperativity.
• Previous research on [(ErCOT)2(μ-X)3]- complexes has explored various bridging ligands (X) to tune magnetic properties.

Purpose of the Study:

• To synthesize and characterize a novel dinuclear erbium complex, [Bu4N][(Er^TMS^COT)2(μ-I)3] (1-I3), for molecular magnetism.
• To investigate the magnetic anisotropy and cooperativity of 1-I3.
• To establish structure-property relationships within the [(ErCOT)2(μ-X)3]- family.

Main Methods:

• Synthesis of the dinuclear erbium complex [Bu4N][(Er^TMS^COT)2(μ-I)3].
• Static and dynamic magnetometry measurements.
• Ab initio computational analysis.

Main Results:

• Complex 1-I3 exhibits longer magnetic relaxation times at low temperatures and a higher spin reversal barrier at high temperatures compared to related compounds.
• Computational analysis attributes low-temperature behavior to dipolar coupling and high-temperature behavior to well-defined Kramers doublets.
• Comparison with single-molecule magnets highlights the importance of the entire low-energy manifold, not just the ground state.

Conclusions:

• The dinuclear erbium complex 1-I3 demonstrates enhanced magnetic properties due to optimized single-ion anisotropy and intramolecular dipolar coupling.
• Bridging ligand electron density influences Er-Er distances and energy levels, impacting magnetic behavior.
• This work provides a framework for magneto-structural correlations in molecular magnets.