Redox Switches for Single-Molecule Magnet Activity: An Ab Initio Insight

Area of Science:

• Coordination Chemistry
• Magnetochemistry
• Computational Chemistry

Background:

• Single-molecule magnet (SMM) activity in dinuclear cobalt complexes.
• Investigated a Co(II) complex (1) with anodic and cathodic switches for SMM behavior.
• Observed SMM activity in oxidized ([1(OEt2)](+)) and reduced ([1](-)) states, demonstrating dual ON/OFF switchability.

Purpose of the Study:

• Elucidate the mechanisms behind the magnetic properties of the Co(II) complex.
• Understand the factors governing magnetization blocking in the SMM states.
• Investigate the role of radical mediation and cobalt ion interactions.

Main Methods:

• Ab initio calculations.
• Broken-symmetry density-functional theory (DFT) methods.
• Analysis of magnetic coupling and molecular orbital delocalization.

Main Results:

• Strong antiferromagnetic interaction between radical and cobalt ions due to magnetic molecular orbital delocalization.
• Identified lack of high axiality in cobalt centers as a reason for limited slow magnetization relaxation.
• Confirmed SMM behavior is switchable via oxidation states.

Conclusions:

• The study provides a mechanistic understanding of the switchable SMM behavior in the dinuclear cobalt complex.
• Computational insights explain the observed magnetic properties and relaxation dynamics.
• The findings highlight the potential for designing novel switchable magnetic materials.