Hydrothermal synthesis, crystal structure and strong photoluminescence of [Er(C₆NO₂H₅)₂ (H₂O)₄ (NO₃)]•2NO₃

Abstract

The hydrothermal reaction of erbium nitrate with isonicotinic acid affords the erbium complex [Er(C₆NO₂H₅)₂ (H₂O)₄ (NO₃)]•2NO₃, which has been structurally characterized by X-ray diffraction. The title complex is characteristic of an isolated structure based on one discrete [Er(C₆NO₂H₅)₂ (H₂O)₄ (NO₃)]²⁺ moiety and two isolated nitrate anions. The [Er(C₆NO₂H₅)₂( H₂O)₄ (NO₃)]²⁺ moieties and the nitrate anions are interconnected via hydrogen bonds to form a two-dimensional supramolecular network. Photoluminescent investigation reveals that the title complex displays a greenish yellow emission band and a red emission band. The greenish yellow emission band is stronger than that of the red emission band. The greenish yellow and red emission bands are identified as the Er³⁺ transitions from the ²H₁₁/₂, ⁴S₃/₂ and ⁴F₉/₂ levels to the ⁴I₁₅/₂ ground state.