Hysteresis Photomodulation within Photochromic Assemblies of [Dy(Tp2−py)F]+ Single-Molecule Magnets : Influence of the Supramolecular Magnetic Couplings.

A 1D coordination compound made of a photochromic dithienylethene linker and [Dy(Tp^2−py)F]⁺ units (with Tp^2−py=tris(3-(2-pyridyl)pyrazolyl)hydroborate) and having tetrakis[3,5-bis(trifluoromethyl)phenyl]borate counterions is reported. Full photoconversion from the closed isomer to the open isomer of the dithienylethene within single crystals allow for monitoring of the transformation by photocrystallography. Magnetic slow relaxation as well as magnetic hysteresis are observed and can be both modulated upon light irradiation. Comparison with previously published structures with similar components highlights the role of the supramolecular organization, and of dipolar couplings within these compounds, in driving the nature of the observed hysteresis photomodulation.

Dr. Nour El Beyrouti, Dr. Felix Houard, Dr. Francisco Javier Valverde-Muñoz, Louis Caussin, Dr. Maher Hojorat, Dr. Marie Cordier, Dr. Elzbieta Trzop, Prof. Stéphane Rigaut, Dr. Boris Le Guennic, Prof. Kévin Bernot, Prof. Lucie Norel, Chem. Eur. J. 2025, 31, e02489, https://doi.org/10.1002/chem.202404274