Slow magnetic relaxation and strong magnetic coupling in the nitroxyl radical complexes of Lanthanide(III) with diamagnetic ground state (Ln = Lu, Eu)

Slow magnetic relaxation and strong magnetic coupling in the nitroxyl radical complexes of Lanthanide(III) with diamagnetic ground state (Ln = Lu, Eu) Full article

Journal

Chemical Science
ISSN: 2041-6520 , E-ISSN: 2041-6539

Output data

Year: 2025, Volume: 16, Number: 1, Pages: 218 - 232 Pages count : 15 DOI: 10.1039/d4sc05035e

Tags

tripodal ligands; lanthanides; single-molecule magnets; europium(III) complexes; lutecium(III) complexes; magnetic properties; EPR spectrum; slow magnetic relaxation

Authors

Sorace Lorenzo ¹ , Dmitriev Alexey A. ² , Perfetti Mauro ¹ , Vostrikova Kira E. ³

Affiliations

1	Department of Chemistry “U. Schiff”, University of Florence and INSTM Research Unit, Via della Lastruccia 3-13, Sesto Fiorentino, Firenze, Italy
2	Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk, Russia
3	Nikolayev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk, Russia

Radical lanthanide complexes are appealing platforms to investigate the possibility to engineer relevant magnetic couplings between the two magnetic centers by exploiting the strongly donating magnetic orbitals of the radical. In this paper, we report a spectroscopic and magnetic study on [LnRad(NO3)3], where Ln = Eu3+ or Lu3+ and Rad is the tridentate tripodal nitroxyl radical 4,4-dimethyl-2,2-bis(pyridin-2-yl)-1,3-oxazolidine-3-oxyl. A thorough magnetic investigation by Electron Paramagnetic Resonance (EPR) spectroscopy and magnetometry, fully supported by ab initio calculations, allowed us to unravel an unprecedentedly large antiferromagnetic coupling between the Eu3+ and the radical (J12 = +19.5 cm−1, +J12S1S2 convention). Remarkably, both europium and lutetium complexes showed slow magnetization dynamics below 20 K. The field and temperature dependent relaxation dynamics, dominated by Raman and direct processes were modelled simultaneously, allowing us to assess that the Raman process is field dependent.

Sorace L. , Dmitriev A.A. , Perfetti M. , Vostrikova K.E.
Slow magnetic relaxation and strong magnetic coupling in the nitroxyl radical complexes of Lanthanide(III) with diamagnetic ground state (Ln = Lu, Eu)
Chemical Science. 2025. V.16. N1. P.218 - 232. DOI: 10.1039/d4sc05035e WOS OpenAlex

Submitted:	Jul 28, 2024
Accepted:	Nov 17, 2024
Published online:	Nov 26, 2024
Published print:	Jan 7, 2025

Web of science:	WOS:001367577200001
OpenAlex:	W4404725510

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