Efeito dos substituintes p-fenil nas propriedades luminescentes de novos complexos de európio(III) e gadolínio(III) com hidrazidas
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Universidade Federal do Espírito Santo
Resumo
New lanthanides (Eu3+ and Gd3+) complexes with hydrazides were successfully
synthesized and the effect of the p-phenyl substituent on the Eu3+ luminescent
properties was evaluated. Crystals of Gd-amino was obtained and its structure was
elucidated by single-crystal X-ray diffraction, revealing Gd3+ centered in a distorted
tricapped trigonal-prismatic molecular geometry. IR spectroscopy and the elucidated
structure confirmed hydrazides acting as bidentate ligands binding to Ln3+ ions
through the oxygen of carbonyl group and the nitrogen of terminal amine, forming a
five-membered ring. The CHN indicated the molecular formulas
[Gd(amino)4(H2O)](NO3)3·(C2H5OH) and [Eu(toluic)3(H2O)3](NO3)3, the Gd3+
complex
had its structure also confirmed by X-ray diffraction in single crystal. Lower T1 state
energies were observed for ligands p-substituted with higher electron donating
capacity groups and higher oscillator strength, such as p-OH and p-NH2. In contrast,
higher lifetimes and quantum efficiencies were obtained for Eu-complexes with p-H
and p-CH3 substituents, which are not deactivator groups and weaker oscillators.
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Lanthanide , Hydrazide , Substituent effect , Photoluminescence , Europium , Gadolinium
Citação
BRANDÃO, Samira Gomes. Efeito dos substituintes p-fenil nas propriedades luminescentes de novos complexos de európio(III) e gadolínio(III) com hidrazidas. 2019. 72 f. Dissertação (Mestrado em Química) – Universidade Federal do Espírito Santo, Centro de Ciências Exatas, Vitória, 2019.