Homochiral Dy2 zero-field single-molecule magnets derived from axial chiral ligands (R)/(S)-octahydro-1,1′-bi-2-naphthyl phosphate

Abstract

The construction of homochiral zero-field single-molecule magnets (SMMs), especially with axial chiral ligands, remains a great challenge. Herein the first examples of homochiral Dy(III) Schiff base complexes based on axial chiral ligands (R)/(S)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-bi-2-naphthyl phosphate (R-HL/S-HL), [Dy₂(R-L/S-L)₂(L_Schiff)₂(H₂O)(MeOH)]·2MeOH·CH₂Cl₂·2MeCN·2H₂O (R-1/S-1) [H₂L_Schiff = (E)-N′-(5-fluoro-2-hydroxybenzylidene)pyrazine-2-carbohydrazide], were synthesized at room temperature, which show ferromagnetic coupling and act as zero-field SMMs, with a U_eff/k value of 61 K at 0 Oe. Ab initio calculations were used to explain their magnetic interaction and magnetic relaxation properties. Furthermore, the magnetic circular dichroism (MCD) spectra of R-1/S-1 revealed that they display obvious magneto-optical effects.