THz-EPR-based Magneto-Structural Correlations for Cobalt(II) Single-Ion Magnets With Bis-Chelate Coordination.

Autor: Pohle MH; Institut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstraße 8, 07743, Jena, Germany., Lohmiller T; EPR4 Energy Joint Lab, Department Spins in Energy Conversion and Quantum Information Science, Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 16, 12489, Berlin, Germany.; Current address: Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Str. 2, 12489, Berlin, Germany., Böhme M; Institut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstraße 8, 07743, Jena, Germany., Rams M; Institute of Physics, Jagiellonian University, 30-348, Kraków, Poland., Ziegenbalg S; Institut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstraße 8, 07743, Jena, Germany., Görls H; Institut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstraße 8, 07743, Jena, Germany., Schnegg A; EPR Research Group, Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany., Plass W; Institut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstraße 8, 07743, Jena, Germany.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2024 Oct 28; Vol. 30 (60), pp. e202401545. Date of Electronic Publication: 2024 Oct 16.
DOI: 10.1002/chem.202401545
Abstrakt: New cobalt(II)-based complexes with [N 2 O 2 ] coordination formed by two bis-chelate ligands were synthesized and characterized by a multi-technique approach. The complexes possess an easy-axis anisotropy (D<0) and magnetic measurements show a field-induced slow relaxation of magnetization. The spin-reversal barriers, i. e., the splitting of the two lowest Kramers doublets (U ZFS ), have been measured by THz-EPR spectroscopy, which allows to distinguish the two crystallographically independent species present in one of the complexes. Based on these experimental U ZFS energies together with those for related complexes reported in literature, it was possible to establish magneto-structural correlations. U ZFS linearly depends on the elongation parameter ϵ T of the (pseudo-)tetrahedral coordination, which is given by the ratio between the average obtuse and acute angles at the cobalt(II) ion, while U ZFS was found to be virtually independent of the twist angle of the chelate planes. With increasing deviation from the orthogonality of the latter, the rhombicity (|E/D|) increases.
(© 2024 The Author(s). Chemistry - A European Journal published by Wiley-VCH GmbH.)
Databáze: MEDLINE
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