A new family of octanuclear lanthanide compounds [Na2Ln6L8(C6H4NH2COO)2(C2H5OH)2(H2O)4(NO3)]·NO3·C2H5OH·nH2O [H2L = 2-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}benzoic acid; Ln = Dy (1) (n = 15); Tb (2), Gd (3) (n = 14); Sm (4) (n = 16)] have been prepared under hydrothermal conditions. The X-ray crystal structure analysis reveals that complexes 1–4 are isomorphous. The core of the structure is a [4 + 2] combination of an Ln4 cubane and an Ln2 unit. The two units are bridged by a nitrate ion, which is located in the center of the cluster and displays an unusual μ8-η2:η2:η4 tridentate bridging mode. The magnetic studies for complex 1 show that the [Na2Dy6] unit exhibits slow magnetic relaxation behavior.

A new family of octanuclear lanthanide compounds [Na2Ln6L8(C6H4NH2COO)2(C2H5OH)2(H2O)4(NO3)]·NO3·C2H5OH·nH2O [H2L = 2-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}benzoic acid; Ln = Dy (1) (n = 15); Tb (2), Gd (3) (n = 14); Sm (4) (n = 16)] have been prepared under hydrothermal conditions. The X-ray crystal structure analysis reveals that complexes 1–4 are isomorphous. The core of the structure is a [4 + 2] combination of an Ln4 cubane and an Ln2 unit. The two units are bridged by a nitrate ion, which is located in the center of the cluster and displays an unusual μ8-η2:η2:η4 tridentate bridging mode. The magnetic studies for complex 1 show that the [Na2Dy6] unit exhibits slow magnetic relaxation behavior.

Two new 3d–4f heterometallic 1D chains of formulae {[Dy2M2L4(NO3)(H2O)3][Dy2M2L4(NO3)(CH3COO)(H2O)2]·NO3·12H2O·2C2H5OH}n [M = Ni (1); Co (2)] have been prepared using the multidentate ligand 2-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}benzoic acid (H2L), which has NO and OO′ chelating pockets that are able to selectively encapsulate LnIII and transition metal ions, respectively. Crystal structure analyses reveal that the two complexes are isostructural and display one-dimensional ladder-like double helical chain structures, in which the two single helical chains {[Dy2M2L4(NO3)(H2O)3]+} and {Dy2M2L4(NO3)(CH3COO)(H2O)2} (M = Ni(1), Co(2)) both run along the c-axis and have opposite chirality. Complexes 1 and 2 represent the first example of 3d–4f double-chain frameworks in which the compositions of the two individual chains are different. Variable temperature dc magnetic susceptibility studies reveal different strengths of ferromagnetic interactions between the magnetic centers in 1 and 2, which is mainly attributed to the different metal centers and finally results in the distinctive magnetic dynamic behaviors.

Two new 3d–4f heterometallic 1D chains of formulae {[Dy2M2L4(NO3)(H2O)3][Dy2M2L4(NO3)(CH3COO)(H2O)2]·NO3·12H2O·2C2H5OH}n [M = Ni (1); Co (2)] have been prepared using the multidentate ligand 2-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}benzoic acid (H2L), which has NO and OO′ chelating pockets that are able to selectively encapsulate LnIII and transition metal ions, respectively. Crystal structure analyses reveal that the two complexes are isostructural and display one-dimensional ladder-like double helical chain structures, in which the two single helical chains {[Dy2M2L4(NO3)(H2O)3]+} and {Dy2M2L4(NO3)(CH3COO)(H2O)2} (M = Ni(1), Co(2)) both run along the c-axis and have opposite chirality. Complexes 1 and 2 represent the first example of 3d–4f double-chain frameworks in which the compositions of the two individual chains are different. Variable temperature dc magnetic susceptibility studies reveal different strengths of ferromagnetic interactions between the magnetic centers in 1 and 2, which is mainly attributed to the different metal centers and finally results in the distinctive magnetic dynamic behaviors.