Circularly polarized luminescence and magneto-optic effects from chiral Dy(<scp>iii</scp>) single molecule magnets

Abstract

A new pair of multifunctional Zn(II)-Dy(III) enantiomers based on the chiral Schiff-base ligands [<i>R</i>,<i>R</i>-ZnLDy(H₂O)(NO₃)₃] (1R2R-ZnDy) and [<i>S</i>,<i>S</i>-ZnLDy(H₂O)(NO₃)₃] (1S2S-ZnDy) (H₂L = phenol, 2,2'-[[(1<i>R</i>,2<i>R</i>/1<i>S</i>,2<i>S</i>)-1,2-diphenyl-1,2-ethanediyl]bis[(<i>E</i>)-nitrilomethylidyne]]bis[6-methoxy]) was synthesized and characterized. Magnetic studies indicate that 1R2R-ZnDy behaves as a single-molecule magnet. Enantiomers 1R2R-ZnDy and 1S2S-ZnDy show chiroptical activity and circularly polarized luminescence in the <i>N</i>,<i>N</i>-dimethylformamide (DMF) solution. The chiral Zn(II)-Dy(III) complexes display magnetic circular dichroism signals at room temperature. Accordingly, these complexes will inspire intriguing research on single-molecule magnets with circular polarization of luminescence activity and magneto-optic effects, which will give new clues to design multifunctional molecular magnetic materials.