Azacyclo-auxiliary ligand-tuned SMMs of dibenzoylmethane Dy(III) complexes

A series of four β-diketone mononuclear dysprosium complexes, namely, Dy(DBM)₃(bpy) (1), Dy(DBM)₃(phen)·Tol (2), Dy(DBM)₃(dpq)·Tol (3), and Dy(DBM)₃(dppz) (4) (bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, dpq = dipyrazine[2,3-f:2′,3′-h]quinoxaline, dppz = dipyrido[3,2-a:2′,3′-c]phenazine, Tol = toluene) have been isolated by the reactions of dibenzoylmethane (DBM), azacyclo-auxiliary ligands and DyCl₃·6H₂O. X-ray crystallographic analysis reveals that complexes 1–4 are all eight-coordinate mononuclear structures. The azacyclo-auxiliary ligands have a dramatic effect on the structure and magnetic characteristics of complexes 1–4, originating from the different degrees of deviation from the ideal coordination symmetries. Complexes 1 and 2 display a single relaxation mode under 0 Oe and complexes 3 and 4 display two single relaxation modes under 2000 Oe.