Homochiral Ferromagnetic Coupling Dy2 Single-Molecule Magnets with Strong Magneto-Optical Faraday Effects at Room Temperature

By the bridging action of the 6-chloro-2-hydroxypyridine (Hchp) ligand and the terminal coordination role of the homochiral ligand, (-)/(+)-3-trifluoroacetyl camphor (L-Htfc/D-Htfc), a pair of enantiomerically pure dysprosium(III) dinuclear complexes, [Dy-2 (L-tfc)(4) (chp)(2) (MeOH)(2)] (L-1) and [Dy-2 (D-tfc)(4) (chp)(2) (MeOH)(2)] (D-1), was obtained. Their circular dichroism (CD) spectra verified their enantiomeric nature. Magnetic investigation indicated that they exhibit ferromagnetic interaction and good zero field single-molecule magnet (SMM) properties. The U-eff/k values of L-1 and D-1 at 0 Oe are 180.5 and 181.3 K, respectively, which are large values for homochiral Dy(III) SMMs. A reasonable explanation for the magnetic properties of L-1 and D-1 was supplied by ab initio calculations. Remarkably, magnetic circular dichroism (MCD) investigation revealed that the chiral Dy-2 enantiomers show a strong magneto-optical Faraday effect at room temperature, suggesting potential applications in magneto-optical devices.

Automated summary

Two enantiomerically pure dysprosium(III) dinuclear complexes were synthesized using specific ligands, exhibiting ferromagnetic interaction and good single-molecule magnet properties. Ab initio calculations provided an explanation for their magnetic properties, while magnetic circular dichroism investigation revealed potential applications in magneto-optical devices.