Switching Magneto-Chiral Dichroism in Lanthanide Single Molecule Magnets – SWITCH-MChD

Switching Magneto-Chiral Dichroism (MChD) in Lanthanide Single Molecule Magnets (SMMs)

The SWITCH-MChD project belongs to the general field of molecular material sciences that aims to combine chirality and magnetism for the observation of the magneto-chiral dichroism and its switching with the long-term objective to use the lanthanide magneto-chiral dichroism for optical readout of magnetic data to manipulate it with external stimuli.

Demonstrate that MChD can be used for optical readout with unpolarized light of lanthanide SMMs and the possibility to trigger the MChD response of lanthanide-SMMs by external stimuli

Lanthanide complexes are at the heart of these researches because they combine large magnetic moment and strong magnetic anisotropy due to the large orbital contribution to the magnetic moment and spin-orbit coupling and unique optical properties. It has indeed been proven very recently that the magnetic information can be stored on single molecules (Single-Molecule Magnets: SMMs) at liquid nitrogen temperature. Recently chirality has proven to be highly appealing to control the spins in molecular materials, for instance through chiral-induced spin selectivity (CISS effect), or through different self-assembly and SMM behavior in non-centrosymmetric Solids. Moreover, Magneto-Chiral Dichroism (MChD), a differential absorption of unpolarized light in chiral magnetized systems, first observed in 1997 in Europium(III) ion chelated by camphrate-based ligands is a fascinating light-matter interaction. The absolute configuration, the direction of light propagation and the relative orientation of the magnetization lead to an enantioselective modification of the absorption or emission of unpolarized light. MChD has been studied so far for a limited number of chiral molecular systems, 2D chiral perovskite and molecular ferrimagnet. The crucial role of the spin-orbit coupling in MChD has been highlighted recently. Chiral lanthanide-based complexes and especially chiral SMMs that are already magnetized are ideal targets for further studies The aim of this project is to design, synthesize and study redox- and photo-switchable chiral lanthanide SMMs with MChD response. Within the SWITCH-MChD project, we intend to tackle several challenges and fundamental questions brought by these systems to the molecular magnetism/spintronics fields and the physical chemistry community: - Is the synthesis of switchable chiral lanthanide systems possible? - Is the isolation of photoisomerized/oxidized states of such systems reachable? - Are in-situ switching accessible within SQUID magnetometer or MChD set-up? - How will redox and photo-irradiation processes affect the MChD? - How to rationalize the lanthanide MChD using quantum calculations? The fundamental SWITCH-MChD research project will generate scientific knowledges and publications in top-level journals contributing to strength the influence of French research in molecular magnetism field and more generally in molecular material sciences.