Syntheses,crystal structures,magnetic and luminescent properties of lanthanide complexes with nitronyl nitroxide radical as ligand

Four lanthanide-nitronyl nitroxide radical complexes, [Ln(hfac)₃(NIT-3Methien)₂] (Ln = Pr (1), Tb (2), Dy (3), Ho (4); hfac = hexafluoroacetylacetonate; NIT-3Methien = 2-(3-methylthiophene)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), have been synthesized, and structurally and magnetically characterized. Single-crystal X-ray diffraction shows that 1–4 have similar mononuclear tri-spin structures in which central Ln(III) ions are eight coordinate by two NIT-3Methien radicals and three hfac coligands. The magnetic studies indicate that there are antiferromagnetic interactions between Ln(III) ions and radicals in 1, 2, and 4, while ferromagnetic interactions are present in 3. The luminescence properties of 2 and 3 were studied.