Structural and Magnetic Properties of 2p-3d-4f Hetero-Tri-Spin Chains Comprising [{Cu(hfac)2-Radical}2] Dimers and Ln(hfac)3(hfac=hexafluoroacetylacetonate)

A functional nitroxide ligand builds up two 2p–3d complexes with different spin ground states and a 2p–3d–4f chain of rings

Three new 2p–3d and 2p–3d–4f complexes derived from a functional nitroxide radical with different spin ground states and spin topologies have been synthesized.

Nitronyl nitroxide bridged 3d–4f hetero-tri-spin chains: synthesis strategy, crystal structure and magnetic properties

Three series of 2p–3d–4f one-dimensional chains based on different substituted nitronyl nitroxide ligands have been synthesized with two kinds of crystal structures.

Syntheses, structures and magnetic properties of the lanthanide complexes of the pyrimidyl-substituted nitronyl nitroxide radical

Four 2p-4f Ln^III-radical complexes, [(NIT-2-Pm)Ln(hfac)₃]·0.5C₇H₁₆ (NIT-2-Pm = 2-pyrimidyl-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxy-3-oxide, hfac = hexafluoroacetylacetonato, Ln = Tb (1), Dy (2), Ho (3) and Er (4)), and four 4f-2p-4f Ln^III-radical-Ln^III complexes, [(μ-NIT-2-Pm)Ln₂(hfac)₆(H₂O)₂]·0.5C₇H₁₆ (Ln = Tb (5), Dy (6), Ho (7) and Er (8)) have been synthesized and characterized structurally and magnetically. These compounds can be selectively obtained by controlling the reaction ratio of Ln(hfac)₃·2H₂O to the radical ligand NIT-2-Pm. The crystal structures show that in the former four complexes 1-4, the NIT-2-Pm radical acts as a terminal bidentate ligand chelating to one Ln^III ion, while in 5-8, the NIT-2-Pm acts as a bridging ligand linking two Ln^III ions to form a binuclear three-spin system. Magnetic studies revealed that complexes 1-4 and 6 show frequency-dependent ac magnetic susceptibilities, suggesting a possible single-molecule magnet behavior. To the best of our knowledge, complexes 3 and 4 are the first Ho-NIT and Er-NIT compounds showing slow magnetic relaxation. Compounds 5-8 represent a rare family of compounds showing the NIT bridged 4f-2p-4f three-spin motif, while complex 6 is a rare NIT bridged multinuclear lanthanide compound possessing SMM-like behaviour. Ab initio calculations were performed on all these complexes. The fitting of the magnetic susceptibilities of these compounds suggests weak antiferromagnetic coupling between the Ln^III and NIT radical in 1-8 and weak ferromagnetic Ln^III-Ln^III interactions in 5-8.

A chimeric design of heterospin 2p–3d, 2p–4f, and 2p–3d–4f complexes using a novel family of paramagnetic dissymmetric compartmental ligands

Original end-off bicompartmental ligands bearing a nitronyl–nitroxide arm have been designed for synthesizing various heterospin molecular systems.

Syntheses, crystal structures, and magnetic properties of cyclic dimer Ln2L2 complexes constructed from (3-pyridinylmethoxy)phenyl-substituted nitronyl nitroxide ligands

Herein, five lanthanide-radical cyclic dimer complexes have been obtained and complex Tb shows the relaxation behavior in zero dc field with an anisotropy barrier Δ/k_B = 21.6 K.