Air-stable redox-active nanomagnets with lanthanide spins radical-bridged by a metal–metal bond

Abstract

Engineering intramolecular exchange interactions between magnetic metal atoms is a ubiquitous strategy for designing molecular magnets. For lanthanides, the localized nature of 4f electrons usually results in weak exchange coupling. Mediating magnetic interactions between lanthanide ions via radical bridges is a fruitful strategy towards stronger coupling. In this work we explore the limiting case when the role of a radical bridge is played by a single unpaired electron. We synthesize an array of air-stable Ln 2 @C 80 (CH 2 Ph) dimetallofullerenes (Ln 2 = Y 2 , Gd 2 , Tb 2 , Dy 2 , Ho 2 , Er 2 , TbY, TbGd) featuring a covalent lanthanide-lanthanide bond. The lanthanide spins are glued together by very strong exchange interactions between 4f moments and a single electron residing on the metal–metal bonding orbital. Tb 2 @C 80 (CH 2 Ph) shows a gigantic coercivity of 8.2 Tesla at 5 K and a high 100-s blocking temperature of magnetization of 25.2 K. The Ln-Ln bonding orbital in Ln 2 @C 80 (CH 2 Ph) is redox active, enabling electrochemical tuning of the magnetism.

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Citation
Liu, F., Velkos, G., Krylov, D. S., Spree, L., Zalibera, M., Ray, R., et al. (2019). Air-stable redox-active nanomagnets with lanthanide spins radical-bridged by a metal–metal bond (London : Nature Publishing Group). London : Nature Publishing Group. https://doi.org//10.1038/s41467-019-08513-6
License
CC BY 4.0 Unported