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Previous issue date: 2013-07-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This is a work involving fundamental studies of chemistry where the synthesis
and structural characterization, as well as a possible future application of these new
compounds as luminescent sensors or sunscreen agents, complexes with 4,4
diaminostilbene-2,2-disulfonic (DSD) and trivalent lanthanide ions La3+, Nd3+, Eu3+,
Gd3+ and Yb3+, were synthesized in the ratio of 3 mmol: 1 mmol (DSD: lanthanides).
The complexes obtained with these ions were present in powder form and were
characterized by complexometric titration with EDTA CHN Elemental analysis,
molecular absorption spectroscopy in the ultraviolet region, the absorption spectroscopy
in the infrared, thermal analysis (TG / DTG), Nuclear Magnetic Resonance - NMR 1H
and Luminescence Spectroscopy. The complexometric titration and CHN analysis,
confirmed the TG / DTG which suggest that these complexes have the following
general chemical formulas:
[La2(C14H12S2O6N2)2(H2O)2Cl2].7H2O,[Nd2(C14H12S2O6N2)2(H2O)2Cl2].6H2O,[Eu2(C14
H12S2O6N2)2(H2O)2Cl2].7H2O,[Gd2(C14H12S2O6N2)2(H2O)2Cl2].4H2O e
[Yb2(C14H12S2O6N2)2(H2O)2].6H2O. The disappearance of the bands in the infrared
spectrum at 2921 cm-1 and 2623 cm-1 and the displacement of the bands in the spectra of
the amine complex indicate that the lanthanide ion is coordinated to the oxygen atoms
and the sulfonate groups of the nitrogens amines, suggesting the formation of the dimer.
The disappearance of the signal and the displacement signal SO3H amines in the 1H
NMR spectrum of this complex are also indicative coordination and dimer formation.
The Thermogravimetry indicates that the DSD is thermally stable in the range of 40? to
385?C and their complexes with lanthanide ions exhibit weight loss between 4 and 5
stages. The Uv-visible spectra indicated that the DSD and complexes exhibit cis
isomers. The analysis of luminescence indicates that the complexes do not exhibit
emission in the region of the lanthanides but an intense emission part of the binder. This
is related to the triplet states of the ligand, which are in the lowest energy state emitting
lanthanide ions, and also the formation of the dimer that suppress the luminescence of
ion Eu3+. The formation of dimer was also confirmed by calculating the europium
complex structure using the model Hamiltonian PM6 and Sparkle / Visando um trabalho de estudos fundamentais da qu?mica, envolvendo a s?ntese e
caracteriza??o estrutural, assim como uma poss?vel aplica??o futura desses novos
compostos como sensores luminescentes ou agentes de prote??o solar, foram sintetizados
os complexos com o ?cido 4,4-diaminoestilbeno-2,2-disulf?nico (DSD) e os ?ons
lantan?deos trivalentes La3+, Nd3+, Eu3+, Gd3+ e Yb3+, preparados na propor??o de 3 mmol:
1mmol (DSD: Lantan?deos). Os complexos obtidos com esses ?ons apresentaram-se na
forma de p? e foram caracterizados por: Titula??o Complexom?trica com EDTA, An?lise
Elementar de CHN, Espectroscopia de Absor??o Molecular na Regi?o do Ultravioleta,
Espectroscopia de Absor??o na Regi?o do Infravermelho, An?lise T?rmica (TG/DTG),
Resson?ncia Magn?tica Nuclear RMN-1H e Espectroscopia de Luminesc?ncia. A titula??o
complexom?trica e a an?lise de CHN, com confirma??o da TG/DTG, sugerem que esses
complexos possuem as seguintes f?rmulas qu?micas gerais:
[La2(C14H12S2O6N2)2(H2O)2Cl2].7H2O, [Nd2(C14H12S2O6N2)2(H2O)2Cl2].6H2O,
[Eu2(C14H12S2O6N2)2(H2O)2Cl2].7H2O, [Gd2(C14H12S2O6N2)2(H2O)2Cl2].4H2O e
[Yb2(C14H12S2O6N2)2(H2O)2].6H2O. O desaparecimento das bandas, no espectro de
Infravermelho, em 2921 cm-1 e 2623 cm-1 e o deslocamento das bandas da amina nos
espectros dos complexos indicam que a coordena??o ao ?on lantan?deo ocorre atrav?s dos
oxig?nios dos grupos sulfonatos e pelos nitrog?nios das aminas, sugerindo a forma??o do
d?mero. O desaparecimento do sinal SO2O-H e o deslocamento do sinal das aminas no
espectro de RMN-1H dos complexos s?o tamb?m indicativos dessa coordena??o e da
forma??o do d?mero. A an?lise t?rmica indica que o DSD ? termicamente est?vel no
intervalo de 40?C at? 385?C e que os seus complexos com os ?ons lantan?deos apresentam
perda de massa entre 4 e 5 etapas. Os espectros de Uv-Vis?vel indicam que DSD e os
complexos apresentam isomeria cis. A an?lise de luminesc?ncia indica que os complexos
n?o apresentam emiss?o na regi?o dos ?ons lantan?deos, mas sim uma emiss?o intensa da
parte do ligante. Isso est? relacionado com os estados tripletos do ligante, que est?o em
energia mais baixa que o estado emissor dos ?ons lantan?deos, e tamb?m com a forma??o
do d?mero que suprime a luminesc?ncia do ?on Eu3+. A forma??o do d?mero tamb?m foi
confirmada atrav?s do c?lculo da estrutura do complexo de eur?pio, utilizando o modelo
Sparkle e hamiltoniano PM6, que mostrou um ponto de m?nimo na superf?cie de energia
potencial desta esp?cie
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17788 |
| Date | 30 July 2013 |
| Creators | Oliveira, Roseane Silva de |
| Contributors | CPF:64145557468, Fernandes, Nedja Suely, CPF:44420773472, http://lattes.cnpq.br/9563490368583906, Pontes, Daniel de Lima, CPF:61954225334, http://lattes.cnpq.br/1903229358912987, Lemos, Francisco das Chagas Dantas de, CPF:19907028487, http://lattes.cnpq.br/8124102870104095, Albuquerque, Rodrigo Queiroz de, CPF:02351274423, http://lattes.cnpq.br/7800041240818025, Hussein, Fabiana Roberta Gon?alves e Silva |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Qu?mica, UFRN, BR, F?sico-Qu?mica; Qu?mica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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