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Beyond the Classical Contributions to Exchange Coupling in Binuclear Transition Metal Complexes
Jakub Chalupský1, Martin Srnec2
1Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo náměstí 2, Prague 6 16610, Czech Republic.
The Journal of Physical Chemistry. A
|March 16, 2021
Summary
Unoccupied metal d orbitals play a key role in magnetic coupling in bimetallic complexes. These orbitals enhance superexchange and become magnetically active, revealing a new interaction mechanism.
Area of Science:
- Inorganic Chemistry
- Computational Chemistry
- Magnetochemistry
Background:
- Magnetically coupled metal ion complexes are crucial in catalysis, single-molecule magnets, and spin-crossover materials.
- Understanding their electronic structures is vital for predicting and controlling their magnetic and catalytic behaviors.
Purpose of the Study:
- To investigate the exchange-coupling mechanisms in six bis-μ-oxo bimetallic M2O2 complexes.
- To elucidate the role of metal d orbitals in the magnetic interactions, including biologically relevant models of non-heme iron enzymes.
Main Methods:
- Utilized advanced multiconfigurational/multireference quantum chemical methods.
- Employed orbital entanglement analysis to probe electronic structure and bonding.
Main Results:
- Revealed a significant and unexpected contribution of predominantly unoccupied metal d orbitals to strong antiferromagnetic coupling.
- Demonstrated a dual role for these orbitals: enhancing superexchange and becoming magnetically active through population.
Conclusions:
- The study uncovers a novel mechanism for magnetic exchange interactions in transition metal complexes.
- Highlights the importance of considering unoccupied orbitals for a complete understanding of magnetic coupling.
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