Synthesis, structure and single-molecule magnet characterization of Dy2 dinuclear complexes with an 8-hydroxyquinoline carbohydrazone ligand

The employment of an 8-hydroxyquinoline carbohydrazone tetradentate ligand, 8-hydroxyquinoline-2carboxaldehyde-(benzoyl)hydrazone (H2L), DyCl3 center dot 6H(2)O and Et3N has led to the formation of dinuclear Dy(III) complex [Dy-2(HL)(2)Cl-4(CH3OH)(2)], (1) and [Dy-2(HL)(2)((PhO)(2)PO2)(4)]center dot 2(CH3OH) (2) in the presence of excess amount of bridging diphenyl phosphate anion, (PhO)(2)PO2-. X-ray crystallography data revealed that two Dy-III atoms in 1 are doubly bridged by the two phenolato oxygen atoms of HL- ligands, however, the Dy-III atoms are bridged by additional two deprotonated mu(1,3)-phosphate anions in 2. Each of the two lanthanide ions is eight-coordinated and is located in the different symmetry with triangular dodecahedron (D-2d) for Dy-III in 1 and elongated triangular bipyramid (D-3h) for Dy-III in 2. Dc magnetic susceptibility studies in the 2-300 K range reveal the weak antiferromagnetic interaction for 1 and 2. Both of them showed field-induced slow magnetic relaxation behavior with the U-eff for 1 of 46.0 K higher than 36.8 K for 2. (C) 2017 Elsevier B.V. All rights reserved.