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Two new complexes, Ln(hfac)3(NITPhOA)2 (Ln = Tb(1), Dy(2); NITPhOA = 2-(4′-amyloxyphenyl)−4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; hfac = hexafluoroacetylacetonate) have been synthesized and characterized. Single crystal X-ray diffraction analysis reveals that both complexes show mononuclear tri-spin structures. The central Ln(III) ion is eight-coordinated by three hfac anions and two NITPhOA molecules, in which the NITPhOA radical acts as monodentate ligand through the NO groups, and the Ln(III) center exhibits a dodecahedron environment. It's interesting that the mononuclear units form a pseudo-one-dimensional chain structure through intermolecular non-covalent N–O⋯O–N contacts of nitroxide groups for 1. Alternating current (ac) magnetic susceptibilities show a frequency-dependent characteristic for both 1 and 2, typical of slow relaxation of magnetization. It's the first time for a lanthanide–radical complex to form a pseudo one-dimensional structure through non-covalent O⋯O contacts.

Four unique infinite 2D Mn(II) aggregates, [Mn 3 ( μ 3 -ade) 2 (OAc) 4 X] n (X = DMF for 1 , DMA for 2 and C 2 H 5 O − for 3 ), [Mn 3 ( μ 3 -ade) 2 (ap) 2 DMF] n ( 4 ) (Hade = adenine; DMF = N , N- dimethylformamide; DMA = N , N- dimethylacetamide, OAc − = acetate ion, H 2 ap = adipic acid) with trinuclear Mn(II) as secondary building units (SBUs), have been successfully synthesized by the assembly of Hade nucleobase and manganese acetate under solvothermal conditions. The resultant complexes can be applied to explore the influence of solvent or co-ligands on the self-assembly and properties of metal complexes based on adenine. The Hade represent tridentate μ 3 -N3, N7, N9 bridging coordination modes. The acetate anions exhibit μ 2 - η 1 :η 1 bidentate, μ 2 - η 1 :η 2 tridentate mode, and μ 2 - η 0 :η 2 bidentate mode. The adipate anions in complex 4 adopt two coordination modes: one is μ 4 - η 2 :η 1 :η 1 :η 1 pentadentate mode, the other one is μ 3 - η 1 :η 2 :η 2 :η 1 hexadentate mode. Their magnetic behaviors exhibit interesting variations, in which the local net magnetization at low temperature increases from 1 to 3 . The Mn II 3 SBUs in 1 – 3 are symmetric with an inversion center, whereas that in 4 has three crystallographically independent Mn II atoms. Thus, the magnetic behaviors of 4 are different from complex 1 – 3 .

A new nitronyl nitroxide-Tb(III) complex, [Tb(hfac)3(NIT-3-Br-4Py)2] (1) (hfac = hexafluoroacetyl -acetonate, NIT-3-Br-4Py = 2-(3′-bromo-4′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), has been synthesized and characterized. The single-crystal X-ray diffraction analysis shows it crystallizes in monoclinic C2/c space group, and is composed of mononuclear molecules. The central Tb(III) ion is eight-coordinated by three bidentate chelating hfac anions and two monodentate NITR ligands, with a dodecahedron environment. Ac magnetic susceptibility study shows that complex 1 exhibits slow magnetic relaxation, suggesting single-molecule magnet behavior.

Five new nitronyl-nitroxide radical-Ln(III) complexes, [Ln(hfac)3(NITPh-2-OCH2Ph)(IMHPh-2–OCH2Ph)] (Ln = Tb(1), Dy(2)) and [Ln(hfac)3(NITPh-2-OCH2Ph)2] (Ln = Ho(3), Er(4), Yb(5)) (hfac = hexafluoroacetylacetonate, NITPh-2-OCH2Ph = 2-(2-benzyloxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, IMHPh-2-O-CH2Ph = the reduced derivative of NITPh-2-OCH2Ph), have been synthesized and characterized. The single-crystal X-ray diffraction analysis shows that all these complexes crystallize in triclinic P 1 − space group, and are composed of mononuclear molecules. The central Ln(III) ion is eight-coordinated by three bidentate chelating hfac anions and two monodentate NITR (or IMHR) molecules, with a dodecahedron environment. There arise a common interesting structural feature for these complexes that the mononuclear molecules form pseudo-binuclear structures through intermolecular non-covalent N–O⋯O–N contacts of nitroxide groups. All of them show intramolecular weak antiferromagnetic interactions between Ln(III) ion and radicals. Alternating current (ac) magnetic susceptibilities display a frequency-dependent characteristic for both Tb(1) and Dy(2), typical of magnetic slow relaxation of single-molecule magnet (SMM) behavior.