Complexos luminescentes de íons lantanídeos trivalentes ligados covalentemente à superfície da sílica gel.

This work reports the synthesis, characterization and investigation of the luminescent properties of lanthanide ion complexes Ln3+ (Ln = Eu, Tb or Gd) with diethylenetriaminepentaacetic ligand (DTPA) covalently bonded to the silica gel surface modified with N-(3-trimethosysilylpropyl)diethylenetriamine (3N) and -diketonates ligands such as 2-thenoyltrifluroacetonate (tta), dibenzoymethanate (dbm), 2-acetyl-1,3-indanedione (acind) and 2-benzoyl-1,3-indanedione (bind) as sensitizers of Ln3+ ion, the hybrids materials were called Sil3N-DTPALn-dik. The elementary analysis (CHN) data demonstrated the efficiency of the silica gel functionalization process. IR spectra showed the main characteristic bands of the functional groups of aminosilane 3N and the ligand DTPA. After the adsorption of the lanthanide and the diketonate ligands, the new hybrid materials exhibited characteristic luminescence emission which demonstrates the intramolecular energy transfer from diketonate ligands to the Ln3+ ion. The investigation of the diketonate ligants coordination to the lanthanide ion was performed through the presence of a broad band in the diffuse reflectance spectra attributed to the (S0S1) transitions centered on those ligands. The study of photophysical properties of materials Sil3N-DTPAEu-dic was performed quantitatively based on the absorption and emission spectra, luminescence decay curves, which revealed that the emission quantum efficiency (), the intensity parameters 2 and 4 and Einstein emission coefficients (A0J) are dependent on the nature of the organic ligands used as antennas. Thus the materials containing the acind and bind as ligands exhibited purest emission colors when compared to the ones containing the tta and dbm. For materials Sil3N-DTPATb-dic was not possible to observe the emission colors from the complex due to the functionalized silica gel emission.

Grantor

Química

Year dc:date.issued

2016

Author dc:creator

• Moura, Jandeilson de Lima.

• Materiais híbridos
• Íons e lantanídeos
• Hybrid materials
• Ions and lanthanides

Language dc:language.iso

pt

Repository record dc:identifier.uri

https://repositorio.ufpb.br/jspui/handle/123456789/1301

OAI identifier oai:identifier

oai:repositorio.ufpb.br:123456789/1301