Solvent-induced a series of dysprosium complexes with different slow relaxation behavior

Abstract As we all know, in the process of complex synthesis, the solvent and coordination environment can make a great change in the structure and properties of the complex. Here, we successfully obtained a series of Dy(III) complexes [Dy(H2L1)(HL1)] (1), [Dy2(HL1)2(CH3COO)2(DMF)2] (2) and [Dy4(L1)4(CH3OH)4] (3) by using (E)-2-hydroxy-N’-((8-hydroxyquinolin-2-yl)methylene)benzohydrazide (H3L1) and Dy(CH3COO)3·6H2O under 80 ​°C in different solvent. In the complexes 1 and 2, the O on the phenolic hydroxyl group of the ligands were not coordinated with Dy(III) ions. But for complex 3, with the increase of the number of Dy(III) ions, in order to meet the coordination saturation of Dy(III) ion, the oxygen on the phenolic hydroxyl was twisted to N,O in the direction of the chelate point and participated in the coordination with them. AC magnetic susceptibilities exhibited that complexes 1 and 2 showed weak out-of-phase (χ’’) component of ac-susceptibilities at zero Oe static magnetic field over the frequency range of 9–999 ​Hz. Complex 3 showed clear single-molecule magnetic behavior, which energy barrier was 19.3 (1) K.