Two Mononuclear Tri-Spin Compounds based on the Lanthanide-Nitronyl Nitroxide Radicals: Synthesis, Crystal Structure, and Magnetic Properties

摘要

Two Ln~(III) complexes based on a nitronyl nitroxide radical were synthesized and characterized structurally and magnetically: [Ln(hfac)_3[NITPhm-Cl]_2][0.5CH_3(CH_2)_5CH_3] [Ln = Er (1), Nd (2)] [hfac = hexafluoroacetylacetonate, NITPhm-Cl = 2-(3′-chlorophenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide]. X-ray crystal structure analysis revealed that the two complexes have similar mononuclear tri-spin structures, in which the metal ions are octacoordinated by two radicals and three hfac molecules to form a slightly distorted dodecahedral arrangement. Each tri-spin unit connects through intermolecular hydrogen bonds, resulting in the formation of one-dimensional wavelike chain. Both of the complexes form a one-dimensional structure by intermolecular hydrogen bonds. Variable temperature magnetic susceptibility measurements studies revealed that there are antiferromagnetic interactions between the paramagnetic ions (Ln~(III) and radical).