Two-dimensional dysprosium(III) coordination polymer: Structure, single-molecule magnetic behavior, proton conduction, and luminescence

Abstract

A new dysprosium (III) coordination polymer [Dy(Hm-dobdc) (H 2 O) 2 ]·H 2 O ( Dy-CP ), was hydrothermal synthesized based on 4,6-dioxido-1,3-benzenedicarboxylate (H 4 m-dobdc) ligand containing carboxyl and phenolic hydroxyl groups. The Dy(III) center adopts an octa-coordinated [DyO 8 ] geometry, which can be described as a twisted square antiprism ( D 4d symmetry). Neighboring Dy(III) ions are interconnected by deprotonated Hm-dobdc 3− ligand to form the two-dimensional infinite layers, which are further linked to generate three-dimensional structure through abundant hydrogen bonds mediated primarily by coordinated and lattice H 2 O molecules. Magnetic studies demonstrates that Dy-CP shows the field-induced slow relaxation of magnetization and the energy barrier U eff / k B and relaxation time τ 0 are 35.3 K and 1.31 × 10 –6 s, respectively. Following the vehicular mechanism, Dy-CP displays proton conductivity with σ equal to 7.77 × 10 –8 S cm −1 at 353 K and 30%RH. Moreover, luminescence spectra reveal that H 4 m-dobdc can sensitize characteristic luminescence of Dy(III) ion. Herein, good magnetism, proton conduction, and luminescence are simultaneously achieved, and thus, Dy-CP is a potential multifunctional coordination polymer material.