SYNTHESIS, CHARACTERIZATION AND STUDIES SPECTROSCOPY OF COORDINATION NETWORKS HYBRID CONTAINING LANTHANIDES. / SÍNTESE, CARACTERIZAÇÃO E ESTUDOS ESPECTROSCÓPICOS DE REDES DE COORDENAÇÃO HÍBRIDAS CONTENDO LANTANÍDEOS.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

In this work is presented the hydrothermal synthesis, the structural studies and spectroscopic properties of three coordination polymers based on lanthanides ions (Eu3+, Tb3+ and Gd3+) and DPA as ligand (DPA= 2,6- dipicolinate). Structural study of [Eu(DPA)(HDPA)(H2O)2.4H2O] displayed the presence of self-assembled dimeric and hexameric water clusters fit in the linear chains and the respective role on the stabilization of supramolecular strucuture. The spectroscopic investigations show the low quantum efficiency (η = 12.7%) caused by large contribution of non-radiative decay rates governing the relaxation process due to vibronic coupling with water molecules. The coordination polymers [Tb(DPA)(HDPA)] and [Gd(DPA)(HDPA)] are isostructurals and allowed the investigation about energy transfers processes. In the case of [Tb(DPA)(HDPA)] compound, the photoluminescence data shown the high quantum yield of emission (≈ 50%) due tho the DPA ligand to be a good sensitizer and the lack of water molecules coordinated directly to metal.

ASSUNTO(S)

redes híbridas lantanídeos quimica hybrid networks lanthanide

ACESSO AO ARTIGO

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