Syntheses, structures and properties of 3d/5d-4f metal complexes with novel polycationic chains

Two 3d/5d-4f metal complexes [DyL₃(H₂O)₂]_n(1.5nHgCl₄) · 2nH₂O (1) and (1.5nZnCl₄) · nH₂O (2), where L and L′ are isonicotinic acid and nicotinic acid, respectively, have been synthesized via hydrothermal reaction and structurally characterized by single-crystal X-ray diffractions. Both complexes are characteristic of a one-dimensional polycationic chain-like structure. Photoluminescent investigation reveals that complex 1 displays emissions in violet, blue and yellow regions, and the violet emission is stronger than the blue and yellow ones. Complex 2 displays emissions in orange and red regions, and the emission are attributed to the characteristic emissions of ⁵D₀ → ⁷F_J (J = 0, 1, 2, 3, 4) of Eu³⁺ ions. Optical absorption spectra reveal the presence of an optical gap of 3.31 and 3.86 eV for 1 and 2, respectively. The magnetic properties show that complex 1 exhibits antiferromagnetic-like interactions.