Spontaneous resolution of Chiral Co(III)Dy(III) single-molecule magnet based on an achiral flexible ligand

Crystallization of two enantiomers Δ-1 and Λ-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 P3121 (Δ-1) and P3221 (Λ-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