Novos complexos indandionatos de fórmulas [Ln(aind)3L(H2O)] e [Ln(bind)3L]∙H2O, (L: 1,10-fenantrolina (phen) ou 4,7-dimetil-1,10-fenantrolina (dmphen), Ln3+: Eu3+ ou Gd3+, aind: 2-acetil-1,3-indandionato e bind: 2-benzoil-1,3-indandionato) foram sintetizados e caracterizados por análise elementar, espectroscopia de absorção na região do infravermelho e análise termogravimétrica. Os dados de caracterização são consistentes com a presença de uma molécula de água de cristalização nas estruturas dos compostos [Ln(bind)3L]∙H2O, enquanto que nos complexos [Ln(aind)3L(H2O)] a molécula de água atua como ligante. As geometrias dos complexos do íon Eu3+, otimizadas pelo modelo SPARKLE/AM1, foram consistentes com os resultados experimentais de luminescência. As propriedades luminescentes dos compostos de Eu3+ são discutidas em termos de parâmetros de intensidade experimentais (Ω2 e Ω4), taxas radiativas (Arad) e não-radiativas (Anrad) e eficiência quântica de emissão (η). Os maiores valores de η foram obtidos para os compostos [Eu(bind)3L]∙H2O, refletindo a ausência de moléculas de água na primeira esfera de coordenação do íon Eu3+.

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.

A novel type of heavy metal adsorbent was prepared by the covalent grafting of thioglycolic acid molecules on a silica gel surface previsiouly modified with 3-aminopropyltrimethoxysilane. The amount of thioglycolic acid immobilized was 1.03 mmol per gram of silica. This material displayed a chelating moiety containing nitrogen, sulfur, and oxygen basic centers which are potentially capable of extracting from aqueous solutions cations such as Cu(II), Ni(II), Co(II), influenced by pH and ionic strength. This process of extraction was carried out by the batch method when similar chemisorption isotherms were observed for all cations. A modified Langmuir equation describes the experimental data.