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

A series of three luminescent single molecule magnets of beta-diketone mononuclear dysprosium complexes, namely, Dy(tfa)(3)(H2O)(2)center dot 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.