A hydroxyl-containing nitronyl nitroxide radical and its Gd(III), Tb(III) Dy(III) complexes: Synthesis, structure and magnetic properties

Highlight•One novel hydroxyl-containing nitronyl nitroxide radical•Three mononuclear tri-spin lanthanide–radical complexes•Hydrogen bondings play important role in the crystal packing.•Ferromagnetic interactions between Ln–Radical•Antiferromagnetic interactions between the intramolecular radicals

One hydroxyl-containing nitronyl nitroxide radical and its three mononuclear tri-spin compounds Ln(hfac)3(NIT-Ph-3-Br-4-OH)2 (Ln = Gd 1,Tb 2, Dy 3, and hfac = hexafluoroacetylacetonate NIT-Ph-3-Br-4-OH = 2-(3′-Br-4′-hydroxyl)-4,4,5,5- tetramethyl-imidazoline-1-oxyl-3-oxide) have been successfully prepared and characterized. Single crystal X-ray analyses show that complexes 1, 2 and 3 are isomorphous, and the center LnIII ions are eight-coordinated. Careful inspection of the structures reveal that short contact between ORadical atoms with phenolic hydroxy was observed, and hydrogen bonding has a significant function in determining the structure. The magnetic studies reveal that the ferromagnetic interactions between Ln–Radical and antiferromagnetic interactions between the intramolecular radicals coexist in these systems. Alternating current (ac) susceptibilities of Tb and Dy complex indicate that there are no obvious frequency dependent out-of-phase signals.

Graphical abstractOne hydroxyl-containing nitronyl nitroxide radical and its three mononuclear tri-spin compounds have been successfully prepared and characterized. Single crystal X-ray analyses show that complexes 1, 2, and 3 are isomorphous, and the center LnIII ions are eight-coordinated. Careful inspection of the structures reveals that short contact between ORadical atoms with phenolic hydroxy was observed, and hydrogen bonding has a significant function in determining the structure. The magnetic studies reveal that the ferromagnetic interactions between Ln–Radical and antiferromagnetic interactions between the intramolecular radicals coexist in these systems.Figure optionsDownload full-size imageDownload as PowerPoint slide