Electronic structure of mononuclear and radical-bridged dinuclear cobalt(II) single-molecule magnets.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40038293.
- Also identified by DOI 10.1038/s41467-025-57210-0 and PMC identifier 11880546.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Metal-organic compounds that feature magnetic bistability have been proposed as bits for magnetic storage, but progress has been slow. Four-coordinate cobalt(II) complexes feature high inversion barriers of the magnetic moment, but they lack magnetic bistability. Developing radical-bridged polynuclear systems is a promising strategy to encounter this; however detailed investigations of such species are scarce. We report an air-stable radical-bridged dinuclear cobalt(II) complex, studied by a combination of magnetometry and spectroscopy. Fits of the data give D = -113 cm<sup>-1</sup> for the zero-field splitting (ZFS) and J = 390 cm<sup>-1</sup> for the metal-radical exchange. Ab initio investigations reveal first-order spin-orbit coupling of the quasi-degenerate <math xmlns="http://www.w3.org/1998/Math/MathML"> <msub><mrow><mi>d</mi></mrow> <mrow> <msup><mrow><mi>x</mi></mrow> <mrow><mn>2</mn></mrow> </msup> <mo>-</mo> <msup><mrow><mi>y</mi></mrow> <mrow><mn>2</mn></mrow> </msup> </mrow> </msub> </math> and d<sub>xy</sub> orbitals to be at the heart of the large ZFS. The corresponding transitions are spectroscopically observed, as are transitions related to the exchange coupling. Finally, signatures of spin-phonon coupling are observed and theoretically analyzed. Furthermore, we demonstrate that the spectral features are not predominantly spin excitations, but largely vibrational in character.