Two Dy₄ complexes based on a Schiff base ligand and two benzoates: Synthesis, structures, and single.molecule magnetic properties

Two Dy-4 clusters with the formulae [Dy-4(L)(4)(PhCO2)(2)(NO3)(2)(EtOH)(2)] (1) and [Dy-4(L)(4)(2-NO2-PhCO2)(2)(NO3)(2) (EtOH)(2)] (2) were obtained by the reactions of Dy(NO3)(3)center dot 6H2O with a Schiff base ligand 2-(((2hydroxy-3-methoxy-benzyl) imino)methyl)-4-methoxyphenol (H2L) and two auxiliary ligands PhCO2H and 2-NO2-PhCO2H in ethanol. Single crystal X-ray diffraction studies evidenced that the two complexes are constructed from Dy-2 units, and display a centrosymmetric tetranuclear linear chain structure. One metal center in the Dy-2 unit in 1 and 2 presents a sevencoordinated geometry, and the other Dy.. ion displays an eight-coordinated geometry. Both complexes are identified as single-molecule magnets with energy barriers of 110 and 108 K, respectively. Theoretical calculations also analyzed the magnetic properties of 1 and 2. CCDC: 2047006, 1; 2047008, 2.