Three lanthanide-nitronyl nitroxide complexes: Syntheses, crystal structures and magnetic properties

One nitronyl nitroxide radical and its three mononuclear tri-spin compounds [Ln(hfac)(3)(NIT-3py-60CH(3))(2)] (Ln = Gd 1, Tb 2, Dy 3 hfac = hexafluoroacetylacetonate; NIT-3py-60CH3 = 2-(3'-pyridine-6'-methoxyl)-4,4,5,5-tetramethylimidazoline-1-oxy1-3-oxide have been prepared and characterized. Single crystal X-ray analyses show that all these three complexes are isomorphous, which crystallize in P2(1)/n space group and show similar radical-Ln(III)-radical structures. The center lanthanide(III) ions of them are eight-coordinate in distorted triangular dodecahedral LnO(8) coordination geometry completed by two NIT-3py-60CH(3) radicals and three hfac(-) ligands. The magnetic studies reveal that ferromagnetic interactions (between intramolecular Ln and radical) and antiferromagnetic interactions (between the intramolecular radicals) are coexist in these complexes. Tb complex displays frequency-dependent signals at low temperature suggesting that it behaves as SMM. (C) 2017 Elsevier Ltd. All rights reserved.