Redes de coordenaÃÃo com Ãons lantanÃdeos: sÃntese, caracterizaÃÃo e estudo espectroscÃpio

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

This work shows the synthesis of new metalorganic frameworks containing Eu3+ and Gd3+ ions, using 1,3,5,-benzenetrisbenzoic acid (H3BTB) as ligand. The H3BTB was synthesized in two steps and characterized by elemental analysis, infrared spectroscopy and nuclear magnetic resonance 1H and 13C; the obtained results confirm all literature dataâs. Networks of coordination with ions lantanideos were obtained by two methodologies: (i) microwave oven and (ii) programmable oven, from ones change reaction time and temperature. From the elemental analysis data of became possible the minimal formulae determination. The infrared spectroscopy shows bands refer to carboxylate groups dislocated for minor frequencies when compared to free ligand, suggesting coordination to lanthanide center. In the spectra of issue networks of europium were observed transitions typical of ion. The band width of middle height of 5D07F0 transition has at least 27 cm-1, indicating polymeric structure. The network of coordination of Eu3+ synthesized by microwave for a time of 90s, had higher quantum efficiency, this due auto-organization structures of 1,3,5-tris (metilphenilbenzene) dimmers. The result of Gd3+ networks phosphorescence suggesting that the energy transfer process is more efficient to MOFEu-II (Eu1,5(BTB)(NO3)1,5(H2O)3), according with observed emission spectrum

ASSUNTO(S)

luminescence 1,3,5-benzenotrisbenzÃico networks of coordination luminescÃncia 1,3,5-benzenetrisbenzÃico lanthanides lantanÃdeos quimica inorganica redes de coordenaÃÃo

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