Magneto-Chiral Dichroism in a One-Dimensional Assembly of Helical Dysprosium(III) Single-Molecule Magnets

• DOI: 10.1021/acs.inorgchem.3c03204
• Publication Date: 2023-10-19T21:10:23Z
• Authors: Maria Sara Raju; Kais Dhbaibi; Maxime Grasser; Vincent Dorcet; Ivan Breslavetz; Kévin Paillot; Nicolas Vanthuyne; Olivier Cador; Geert L. J. A. Ri...; Boris Le Guennic; Jeanne Crassous; Fabrice Pointillart; Cyrille Train; Matteo Atzori
• Keywords: Helicene; Magnetic circular dichroism; Crystallography; Enantiomer; 600; Symmetry breaking; Circular dichroism; 540; Magnetization; Magnet; Enantioselective synthesis; [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry; Magnetic field; Lanthanide; Stereochemistry; Chiral symmetry breaking; Dysprosium; [CHIM.COOR]Chemical Sciences/Coordination chemistry; Chirality; Single-molecule magnet; Spectral line

Here we report magneto-chiral dichroism (MChD) detected through visible and near-infrared light absorption of a chiral dysprosium(III) coordination polymer. The two enantiomers of [DyIII(H6(py)2)(hfac)3]n [H6(py)2 = 2,15-bis(4-pyridyl)ethynylcarbo[6]helicene; hfac- = 1,1,1,5,5,5-hexafluoroacetylacetonate], where the chirality is provided by a functionalized helicene ligand, were structurally, spectroscopically, and magnetically investigated. Magnetic measurements reveal a slow relaxation of the magnetization, with differences between enantiopure and racemic systems rationalized on the basis of theoretical calculations. When the enantiopure complexes are irradiated with unpolarized light in a magnetic field, they exhibit multiple MChD signals associated with the f-f electronic transitions of DyIII, thus providing the coexistence of MChD-active absorptions and single-molecule-magnet (SMM) behavior. These findings clearly show the potential that rationally designed chiral SMMs have in enabling the optical readout of magnetic memory through MChD.