A centrosymmetric Dy2 compound derived from acylhydrazone Schiff base ligand exhibiting zero-field single-molecule magnet behavior

Abstract

Based on acylhydrazone Schiff base ligand (2,3′-Hpcad, N3-(2-pyridoyl)-3-pyridinecarboxamidrazone), a binuclear DyIII compound, [Dy2(2,3′-pcad)2(C6H5COO)4(H2O)2] (1), has been successfully prepared by the hydrothermal synthesis method, and fully characterized by single-crystal X-ray diffraction, elemental analysis, Raman spectra, diffuse reflectance spectroscopy and magnetic property measurement system. Compond 1 exhibits a centrosymmetric binuclear structure bridged by benzoate groups and each eight-coordinated DyIII ion is located in a slightly distorted biaugmented trigonal prism configuration (C2v-BTPR). In addition, alternating-current magnetic susceptibility measurements illustrate that 1 exhibits zero-field single-molecule magnet behavior with the higher effective energy barrier (Ueff) value of 114.0 K compared to other Dy2 compounds with C2v-BTPR configuration. In addition, this study reveals configuration of each DyIII ion and intra-molecular magnetic coupling of two DyIII ions may synergistically effect Dy2-SMMs properties. Furthermore, the band gap energy of 1 is found to be 2.65 eV, which proves 1 could be used as the wide-gap semiconductor.