Near-infrared-emitting rare-earth chelates based on 8-hydroxyquinoline have appeared frequently in recent literature, because they are promising candidates for active components in near-infrared-luminescent optical devices, such as optical amplifiers, organic light-emitting diodes, .... Unfortunately, the absence of a full structural investigation of these rare-earth quinolinates is hampering the further development of rare-earth quinolinate based materials, because the luminescence output cannot be related to the structural properties. After an elaborate structural elucidation of the rare-earth quinolinate chemistry we can conclude that basically three types of structures can be formed, depending on the reaction conditions: tris complexes, corresponding to a 1:3 metal-to-ligand ratio, tetrakis complexes, corresponding to a 1:4 metal-to-ligand ratio, and trimeric complexes, with a 3:8 metal-to-ligand ratio. The intensity of the emitted near-infrared luminescence of the erbium(Ill) complexes is highest for the tetrakis complexes of the dihalogenated 8-hydroxyquinolinates.
ASJC Scopus subject areas
- Inorganic Chemistry
Van Deun, R., Fias, P., Nockemann, P., Schepers, A., Parac-Vogt, T. N., Van Hecke, K., Van Meervelt, L., & Binnemans, K. (2004). Rare-earth quinolinates: Infrared-emitting molecular materials with a rich structural chemistry. Inorganic Chemistry, 43(26), 8461-8469. https://doi.org/10.1021/ic048736a