Luminescent single molecule magnets of a series of β-diketone dysprosium complexes

Abstract

A series of three luminescent single molecule magnets of β-diketone mononuclear dysprosium complexes, namely, Dy(tfa)₃(H₂O)₂·Me₂CO (1), Dy(tfa)₃(bpy) (2) and Dy(tfa)₃(phen) (3) (tfa = trifluoroacetylacetonate, bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, C₃H₆O = Me₂CO) have been isolated. Single-crystal X-ray analysis shows all the central Dy(III) ions are eight-coordinated adopting the coordination geometries of the distorted dodecahedron, bicapped trigonal prism and square antiprism for complexes 1–3, respectively. Magnetic analyses exhibit slow magnetic relaxation with the barrier heights (U_eff/k_B) of 41 K, 33 K and 55 K for complexes 1–3, respectively. Photo-luminescent analysis reveal that complexes 1–3 exhibit the typical yellow luminescence of Dy(III) ions. The correlation between the structure and physical properties has been investigated.