Novel luminescent Eu3+-indandionate complexes containing heterobiaryl ligands

• Published in: Journal of the Brazilian Chemical Society Vol. 25; no. 11; pp. 2080 - 2087
• Main Authors: Resende Filho, João B. M., Silva, Jannine C., Vale, Juliana A., Brito, Hermi F., Faustino, Wagner M., Espínola, José G. P., Felinto, Maria C. F. C., Teotonio, Ercules E. S.
• Format: Journal Article
• Language: English; Portuguese
• Published: Sociedade Brasileira de Química 01.11.2014
• Subjects: CHEMISTRY, MULTIDISCIPLINARY; 4,7-dimethyl-1,10-phenanthroline; 2-acyl-1,3-indandionates; lanthanides
• ISSN: 1678-4790
• DOI: 10.5935/0103-5053.20140197

Novel Ln3+-indandionate complexes of formulas [Ln(aind)3L(H2O)] and [Ln(bind)3L]∙H2O (L: 1,10-phenanthroline (phen) or 4,7-dimethyl-1,10-phenanthroline (dmphen), Ln3+: Eu3+ or Gd3+, aind: 2-acetyl-1,3-indandionate and bind: 2-benzoyl-1,3-indandionate) were synthesized and characterized by elemental analysis, infrared spectroscopy, and thermogravimetric analyses. The characterization data are consistent with the presence of a water lattice molecule in the [Ln(bind)3L]∙H2O compounds. However, the data also suggest that the water acts as a coordinated molecule in the [Ln(aind)3L(H2O)] ones. Theoretical geometries of the Eu3+-complexes have been optimized via the SPARKLE/AM1 Model for lanthanide complexes that are consistent with their luminescence experimental data. The photoluminescence properties of the Eu3+-compounds have been discussed in terms of experimental intensity parameters (Ω2 and Ω4), radiative (Arad), and non-radiative (Anrad) spontaneous emission coefficients. The higher values of emission quantum efficiency (η) of the [Eu(bind)3L]∙H2O compounds reflect the absence of luminescence-quenching water molecule in their first coordination spheres.