Spontaneous Resolution of Chiral Co(III)Dy(III) Single-Molecule Magnet Based on an Achiral Flexible Ligand

Crystallization of two enantiomers Delta-1 and Lambda-1 was achieved by using an achiral flexible ligand H4L (2,2'-[1,2-ethanediylbis[(hydroxyethylimino)methylene]]bis[6-methoxy-4-methyl-phenol]). The absolute configurations of the enantiomers in P3(1)21 (Delta-1) and P3(2)21 (Lambda-1) are confirmed by the X-ray single crystal diffraction. Solid-state circular dichroism spectra show that two enantiomers have absorption peaks of mirror symmetry. The experimental energy barrier of 88.9 K derived from the alternating-current magnetic measurements is consistent with the energy gap (89.9 K) between two lowest Kramers doublets calculated by ab initio method.