Three new complexes containing MnII2MoIII zigzag chains have been synthesized and structurally characterized. The crystal structure of complex 3 consists of two linkage isomers of the MoIIIMnII2 chains, which correspond to 1 and 2, respectively. Both complex 1 and 3 show slow magnetic relaxation behavior with an energy barrier of Δ/kB = 69.5 K and 68.8 K, respectively, whereas complex 2 is a simple paramagnet. The linear apical MoIII–CN–MnII pairs provide the required magnetic anisotropy for the slow magnetic relaxation.

Two manganese(II) homometallic coordination polymers of compositions [Mn(CN)2(pz)]n (1) and {[Mn4(CN)8(bpy)3(EtOH)1.14(H2O)0.86]·bpy}n (2) have been synthesized in an inert atmosphere. In these compounds, metal cyanide 2D layers are linked into 3D networks by pillar ligands. Antiferromagnetic coupling occurs between Mn(II) ions and the antiferromagnetic ordering in these compounds is observed with Neel temperatures (TN) of 20.0 K in complex 1 and 8.0 K in complex 2.

A series of lanthanide nitronyl nitroxide radical compounds, [Ln(hfac)3(NITPh-p-N(CH3)2)2]·xC7H16 (Ln = La (1), Eu (2), Gd (3), Tb (4), Dy (5), Er (6), hfac = hexafluoroacetylacetonate; NITPh-p-N(CH3)2 = 4′-dimethylamino-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, x = 2/3 for complexes 1, 2, 3 and 6, and 0 for 4 and 5), have been synthesized and structurally characterized. X-Ray crystallographic analyses show that the structures of the six compounds are similar and all consist of isolated molecules, in which central Ln(III) ions are coordinated to six oxygen atoms from three hexafluoroacetylacetonate ligands and two oxygen atoms from nitronyl nitroxide radicals. Variable-temperature magnetic susceptibility studies reveal ferromagnetic interactions between the Gd(III) ion and nitronyl nitroxide radical in complex 3. Ac magnetic susceptibility measurements of complexes 4 and 5 exhibit frequency-dependent out-of-phase signals, indicating single-molecule magnet (SMM) behavior.

A series of lanthanide nitronyl nitroxide radical compounds, [Ln(hfac)3(NITPh-p-N(CH3)2)2]·xC7H16 (Ln = La (1), Eu (2), Gd (3), Tb (4), Dy (5), Er (6), hfac = hexafluoroacetylacetonate; NITPh-p-N(CH3)2 = 4′-dimethylamino-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, x = 2/3 for complexes 1, 2, 3 and 6, and 0 for 4 and 5), have been synthesized and structurally characterized. X-Ray crystallographic analyses show that the structures of the six compounds are similar and all consist of isolated molecules, in which central Ln(III) ions are coordinated to six oxygen atoms from three hexafluoroacetylacetonate ligands and two oxygen atoms from nitronyl nitroxide radicals. Variable-temperature magnetic susceptibility studies reveal ferromagnetic interactions between the Gd(III) ion and nitronyl nitroxide radical in complex 3. Ac magnetic susceptibility measurements of complexes 4 and 5 exhibit frequency-dependent out-of-phase signals, indicating single-molecule magnet (SMM) behavior.

•Two new coordination polymers were synthesized from the diffusion reaction.•Both complexes have 3D uninodal 6-connected (412,63) net topology.•The btb ligand can deliver very weak magnetic interaction.The diffusion reaction of 1,4-bis(1,2,4-triazol-1-yl)butane (btb) with Co(II)/Ni(II) ions as well as counter anions (PF6−) yielded two new coordination polymers, [Co1.5(btb)4.5](PF6)3 (1) and [Ni2(btb)6](PF6)4 (2). Both complexes have 3D uninodal 6-connected (412,63) net topology, forming triple interpenetrating structure. The distance between adjacent metal ions via btb bridging ligand is in the range of 13.930–14.181 Å and 13.982–14.086 Å, respectively. The magnetic behaviors of complexes 1 and 2 have been analyzed by one-ion approximation with spin–orbit coupling and zero-field splitting, respectively.Graphical abstractTwo coordination polymers: [Co1.5(btb)4.5](PF6)3 (1) and [Ni2(btb)6](PF6)4 (2) were synthesized by using ligands btb, CoCl2·6H2O(NiCl2·6H2O) and NH4PF6 as starting materials. Both complexes consist of 3D α-polonium framework, in which adjacent metal ions are linked with btb ligands. The variable-temperature magnetic susceptibility studies reveal the btb ligand transmits very weak magnetic interaction.

Two mononuclear Dy(III) complexes, [DyIII(hfac)3(tmphen)] (1) and [DyIII(acac)3(tmphen)]·2H2O (2) (tmphen = 3,4,7,8-tetramethyl-1,10-phenanthroline, hfac = hexafluoroacetylacetone, acac = acetylacetone) have been synthesized and structurally characterized by single crystal X-ray diffraction. Magnetic properties indicate that both of the complexes exhibit SMM behavior, and complex 1 is the first typical derivative of phenanthroline containing D2d-Dy(III) based mononuclear single molecule magnets. The energy barrier (Ueff/kB) of complex 2 (130.42 K) is much higher than that of complex 1 (35.09 K), indicating that the local symmetry of Dy(III) ions (D2d for 1, D4d for 2) plays an important role in magnetic behaviors.

•Synthesize two mononuclear tri-spin complexes based on lanthanide ions and nitronyl nitroxide radicals.•Complex 1 is dodecahedral (DD) geometry; while in complex 2, the geometry is square antiprism (SAPR).•Complexes 1 and 2 exhibit slow magnetic relaxation, suggesting single-molecule magnet behavior.Two Lanthanide compounds with nitronyl nitroxide radicals [Dy(hfac)3(NITPh-p-Cl)2·0.5CH3(CH2)5CH3] (1) (hfac = hexafluoroacetylacetonate; NITPh-p-Cl = 4′-chlorphenyl-4,4,5,5-tetramethylimida-zoline-1-oxyl-3-oxide, CH3(CH2)5CH3 is heptane as solvent molecule) and [Tb(hfac)3(NITPh-p-Cl)2] (2) were synthesized and structurally characterized. The X-ray crystallographic analyses show that the structures of the two compounds are similar and all consist of isolated molecules, in which central Ln(III) ions are coordinated to six oxygen atoms from three hexafluoroacetylacetonate ligands and two oxygen atoms from nitronyl nitroxide radicals. Ac magnetic susceptibility studies show complexes 1 and 2 exhibit slow magnetic relaxation, suggesting single-molecule magnet behavior.Two Lanthanide-radical compounds were synthesized. Complex 1 is dodecahedral geometry; while complex 2 is square antiprism geometry. Two complexes show intramolecular antiferromagnetic interactions and exhibit slow magnetic relaxation behavior.

•Two new copper(II) complexes were synthesized and structurally characterized.•The magnetic analysis was carried out according to their different structures.•Different bridges play the dominate role in the magnetic properties.By utilizing 4-amino-3,5-dimethyl-1,2,4-triazole as ligand, two new compounds, [Cu3(N3)6(L)4] (1) and {[Cu3(NO3)5(OH)(L)3]·0.5H2O}n (2) (L = 4-amino-3,5-dimethyl-1,2,4-triazole), have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, UV–Vis spectra and magnetic measurements. Compound 1 is a trinuclear Cu(II) complex, containing four L ligands and six N3− anions. In compound 2, a one-dimensional chain structure was formed between the trinuclear Cu(II) units connected to each other by NO3− anions. The magnetic analysis indicates a middle strong antiferromagnetic exchange is propagated by 1,2,4-triazole bridging ligand.Graphical abstractTwo new triazole-bridged complexes, [Cu3(N3)6(L)4] (1) and {[Cu3(NO3)5(OH)(L)3]·0.5H2O}n (2) (L = 4-amino-3,5-dimethanyl-1,2,4-triazole), have been synthesized and structurally characterized. Compound 1 is a trinuclear Cu(II) complex and compound 2 has a one-dimensional chain structure. The magnetic analysis indicates intramolecular antiferromagnetic coupling between Cu(II) ions is propagated.

•Two 3d-4f complexes were synthesized and structurally characterized.•An approximate method was used to interpret the magnetic behavior.•Different architectures can be formed by β-diketonate ligand cleaving or not.Two new complexes, [MnIIILDyIII(hfac)2(CF3COO)(H2O)][DyIII(hfac)3(CF3COO)(H2O)]·2CHCl3 (1) and [MnIIIL(H2O)][TbIII(hfac)4]·CHCl3 (2) [L = N,N'-ethylene-bis(3-methoxy-salicylideneiminate), hfac = hexafluoroacetylacetone] were synthesized and structural characterized by X-ray single-crystal diffraction. The magnetic analysis was carried out by using the Hamiltonian of Ĥ = ΔĴz2 for lanthanide ions and Ĥ = DŜz2 for Mn(III) ion, and the best fitting gives D = ± 2.98 cm− 1, Δ = − 0.0014 cm− 1, zJ′ = − 0.017 cm− 1, gDy = 1.37, gMn = 2.02 for complex 1 and D = ± 0.23 cm− 1, Δ = 0.0034 cm− 1, gTb = 1.52, gMn = 1.99 for complex 2.Two new 3d-4f heterometal complexes were synthesized and structurally characterized. The magnetic analysis was carried out by using the Hamiltonian of Ĥ = ΔĴz2 for lanthanide ions and the magnetic studies reveal that a weak antiferromagnetic interaction may be exist between the Dy(III) ion and Mn(III) ion in complex 1.

Two novel complexes, [{Mn(salen)}2{Mn(salen)(CH3OH)}{Cr(CN)6}]n·2nCH3CN·nCH3OH (1) and [Mn(5-Clsalmen)(CH3OH)(H2O)]2n[{Mn(5-Clsalmen)(μ-CN)}Cr(CN)5]n·5.5nH2O (2) (salen2− = N,N′-ethylene-bis(salicylideneiminato) dianion; 5-Clsalmen2− = N,N′-(1-methylethylene)-bis(5-chlorosalicylideneiminato) dianion), were synthesized and structurally characterized by X-ray single-crystal diffraction. The structural analyses show that complex 1 consists of one-dimensional (1D) alternating chains formed by the [{Cr(CN)6}{Mn(salen)}4{Mn(salen)(CH3OH)}2]3+ heptanuclear cations and [Cr(CN)6]3− anions. While in complex 2, the hexacyanochromate(III) anion acts as a bis-monodentate ligand through two trans-cyano groups to bridge two [Mn(5-Clsalmen)]+ cations to form a straight chain. The magnetic analysis indicates that complex 1 shows three-dimensional (3D) antiferromagnetic ordering with the Néel temperature of 5.0 K, and it is a metamagnet displaying antiferromagnetic to ferromagnetic transition at a critical field of about 2.6 kOe at 2 K. Complex 2 behaves as a molecular magnet with Tc = 3.0 K.

The flexibility of the 3D framework derived from Ni(II) and an aromatic dicarboxylate allows for the incorporation of different second bridges, and the resulting materials can be a metamagnet or a paramagnet depending upon the length of the second bridge.

Three complexes, [Mn(salphen)(H2O)]2[Fe(CN)5(NO)]·2CH3OH (1) (salphen = N,N′-phenylenebis(salicylideneiminato) dianion), [Mn(naphtmen)(CH3OH)]2[Fe(CN)5(NO)] (2) (naphtmen = N,N′-(1,1,2,2-tetramethylethylene)bis(naphthylideneiminato) dianion), and {[Mn(salen)]2[Fe(CN)5(NO)]·H2O}n (3) (salen = N,N′-ethylene-bis(salicylideneiminato) dianion), were synthesized and structurally characterized by X-ray single-crystal diffraction. The structural analyses show that complexes 1 and 2 consist of the discrete linear trinuclear [Mn(SB)]2[Fe(CN)5(NO)] units (SB = salphen for 1, naphtmen for 2); in complex 3, the nitroprusside anion coordinates to the axial sites of the four [Mn(salen)]+ entities through its four cyano nitrogen atoms, providing a two-dimensional network. The magnetic analysis indicates that the nitroprusside bridging ligand propagates a very weak antiferromagnetic exchange and single-ion anisotropy (D) plays an important role in the overall magnetic properties. Different from complexes 2 and 3, complex 1 shows a typical spin-flop transition with a critical field of 20 kOe.

Two mononuclear Dy(III) complexes, [DyIII(hfac)3(tmphen)] (1) and [DyIII(acac)3(tmphen)]·2H2O (2) (tmphen = 3,4,7,8-tetramethyl-1,10-phenanthroline, hfac = hexafluoroacetylacetone, acac = acetylacetone) have been synthesized and structurally characterized by single crystal X-ray diffraction. Magnetic properties indicate that both of the complexes exhibit SMM behavior, and complex 1 is the first typical derivative of phenanthroline containing D2d-Dy(III) based mononuclear single molecule magnets. The energy barrier (Ueff/kB) of complex 2 (130.42 K) is much higher than that of complex 1 (35.09 K), indicating that the local symmetry of Dy(III) ions (D2d for 1, D4d for 2) plays an important role in magnetic behaviors.

Three new complexes containing MnII2MoIII zigzag chains have been synthesized and structurally characterized. The crystal structure of complex 3 consists of two linkage isomers of the MoIIIMnII2 chains, which correspond to 1 and 2, respectively. Both complex 1 and 3 show slow magnetic relaxation behavior with an energy barrier of Δ/kB = 69.5 K and 68.8 K, respectively, whereas complex 2 is a simple paramagnet. The linear apical MoIII–CN–MnII pairs provide the required magnetic anisotropy for the slow magnetic relaxation.

The flexibility of the 3D framework derived from Ni(II) and an aromatic dicarboxylate allows for the incorporation of different second bridges, and the resulting materials can be a metamagnet or a paramagnet depending upon the length of the second bridge.