Syntheses, Structures And Magnetic Properties Of2p-4f And2p-3d-4f Complexs

The synthesis and study of metal complexes with nitronyl nitroxide radical have been one of the most attractive fields in the molecular-based magnetic materials. Focused on this topic, twenty-five new2p-4f and2p-3d-4f complexes have been synthesized by reacting nitronyl nitroxide radicals with metal ions in this work. Their structures have been determined by X-ray crystallographic methods, and they have been characterized by elemental analyses, IR and DC/AC magnetic measurements. Main contents are as follows:1. By using2-methyl, cyclopropanyl and3-Bromo-4-methoxyphenyl substituted nitronyl nitroxide as ligand. Reaction of the ligands with Ln(hfac)3-2H2O, nine1D chain complexes have been obtained, namely,[Ln(hfac)3(NIT-Me)]n (LnⅢ=Y, Tb, Dy),[Ln(hfac)3(NIT-C3H5)]n (LnⅢ=Gd, Tb) and [Ln(hfac)3(NIT-3BrPhOMe)]n (LnⅢ=Gd, Tb, Dy). The AC magnetic measurements show that complexes [Dy(hfac)3(NIT-Me)]n and [Tb(hfac)3(NIT-C3H5)]n exhibit slow magnetic relaxation in low temperature, suggesting SCM behavior. Complexes [Ln(hfac)3(NIT-3BrPhO Me)]n (LnⅢ=Tb, Dy) exhibit the coexistence of slow magnetic relaxation and antiferromagnetic three-dimensional magnetic ordering.2. By using benzimidazolyl,2-methyl-benzimidazolyl and4-methoxy-3-pyridine substituted nitronyl nitroxide as ligands. Reaction of the ligands with Ln(tfa)3-2H2O and Ln(hfac)3-2H2O. Nine mononuclear2p-4f compounds have been synthesized. They are Ln(tfa)3(NIT-BzImH)](LnⅢ=Gd, Tb,Dy),[Ln(hfac)3(NIT-BzImCH3)](LnⅢ=Gd, Tb, Y) and [Ln(hfac)3(NIT-3BDOCH3)](LnⅢ=Gd, Tb, Dy). The AC magnetic measurements show that complexes [Ln(tfa)3(NIT-BzImH)](LnⅢ=Tb, Dy),[Tb(hfac)3(NIT-BzImCH3)] and [Tb(hfac)3(NIT-3BDOCH3)] exhibit slow magnetic relaxation in low temperature, suggesting SMM behavior.3. Using4-propoxyphenyl and4-benzyphenyl substituted nitronyl nitroxide as ligands. Reaction of the ligands with Ln(hfac)3-2H2O and Cu(hfac)2-2H2O at the same time. Six1D2p-3d-4f chains have been synthesized. They are [Ln3Cu(hfac)11(NIT-PhOPr)4]n (LnⅢ=Gd, Tb, Dy), and [Ln3Cu(hfac)11 (NIT-PhOCH2Ph)4]n (LnⅢ=Gd, Tb, Dy)。The AC magnetic measurements show that complexes [Ln3Cu(hfac)11(NIT-PhOPr)4]n(LnⅢ=Tb, Dy) exhibit slow magnetic relaxation in low temperature, suggesting SCM behavior.