Chiral Star-Shaped [CoLn] Clusters with Enantiopure Schiff Bases: Synthesis, Structure, and Magnetism.

Two enantiomeric pairs of new 3d-4f heterometallic clusters have been synthesized from two enantiomer Schiff base derivatives: (/)-2-[(2-hydroxy-1-phenylethylimino)methyl] phenol (-/-HL). The formulae of the series clusters are CoLn(-L) (Ln = Dy (), Gd ()), CoLn (-L) (Ln = Dy (), Gd ()), whose crystal structures and magnetic properties have been characterized. Structural analysis indicated that the above clusters crystallize in the chiral 23 group space. The central lanthanide ion has a coordination geometry of surrounded by three [Co(L)] anions using six aliphatic oxygen atoms of L featuring a star-shaped [CoLn] configuration. Magnetic measurements showed the presence of slow magnetic relaxation with an effective energy barrier of 22.33 K in the Dy derivatives under a zero-dc field. Furthermore, the circular dichroism (CD) spectra of and confirmed their enantiomeric nature.