Two enantiomeric pairs of new 3d-4f heterometallic clusters have been synthesized from two enantiomer Schiff base derivatives: ( R / S )-2-[(2-hydroxy-1-phenylethylimino)methyl] phenol ( R -/ S -H 2 L). The formulae of the series clusters are Co 3 Ln( R -L) 6 (Ln = Dy ( 1R ), Gd ( 2R )), Co 3 Ln ( S -L) 6 (Ln = Dy ( 1S ), Gd ( 2S )), whose crystal structures and magnetic properties have been characterized. Structural analysis indicated that the above clusters crystallize in the chiral P 2 1 3 group space. The central lanthanide ion has a coordination geometry of D 3 surrounded by three [Co III (L) 2 ] - anions using six aliphatic oxygen atoms of L 2- featuring a star-shaped [Co III 3 Ln III ] configuration. Magnetic measurements showed the presence of slow magnetic relaxation with an effective energy barrier of 22.33 K in the Dy III derivatives under a zero-dc field. Furthermore, the circular dichroism (CD) spectra of 1R and 1S confirmed their enantiomeric nature.