Título: | STUDY OF TERNARY COMPLEXES OF CO(II) AND NI(II) WITH THE AMINO ACIDS GLYCINE, SERINE, ASPARTIC ACID AND GUANIDINOACETIC ACID, IN SOLUTION | |||||||
Autor: |
PEDRO ANTONIO LUZ PUPPIN |
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Colaborador(es): |
JUDITH FELCMAN - Orientador |
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Catalogação: | 10/JAN/2007 | Língua(s): | PORTUGUESE - BRAZIL |
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Tipo: | TEXT | Subtipo: | THESIS | |||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=9456&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=9456&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.9456 | |||||||
Resumo: | ||||||||
The binary and ternary systems of cobalt(II) and nickel(II) with the
aminoacids glycine, serine, aspartic acid and guanidinoacetic acid were studied. Theamino acids glycine - Gly, serine - Ser, aspartic acid - Asp and guanidinoaceticacid - Gaa are all involved in several biochemical processes. These amino acidsare constituents of many proteins, which are in turn, good complexing agents.
Thestudy of metal-amino acid interactions are of great interest, as they
representsimplified models for the analysis of the changes caused in the
proteins properties, when these bond to metal ions. It was determined, in this
work, theformation and interaction constants of species belonging to the
binary and ternarysystems of cobalt(II) and nickel(II). UV-Vis
spectrophotometric analysis werealso made for each of the systems studied. The comparison of the UV-Vis spectrain different pHs with the species` distribution graphs indicated a relationshipbetween the d-d bands and the respective proposed specie. When analyzing theformation constants of the ternary complexes ML1L2, the Ni(II) complexesshowed higher values than those of respective Co(II) complexes, a pattern whichis in accordance with the Irving-Williams series. In conclusion to the comparisonof the UV-Vis spectra with those in literature, we have that the bands found, aswell as their respective position and molar absortivities, refer themselves to nonregularoctahedral complexes. It was verified that the greatest intramolecularinteractions beetween the ligands in the complexes studied were those of thespecies cointaining Gaa. From the graphs of species distribution in terms of pH, we were able to verify that in biological pH, for all three systems of Co(II),protonated ternary species were predominant. No generalizations were visible forthe Ni(II) systems. In the Ni Gly Ser system,
the specie NiGlySer is present ingreater amounts in pH close to 7;
in the Ni-Asp-Gly system, the ternary speciesare formed in lower quantities
in lower pH values and in higher and biological pHvalues, binary species of
hydrolyzed NiAsp are predominant; in Ni-Ser-Gaasystems, protonated ternary
species are in higher concentration. In pH 9,hydrolyzed
(binary and/or ternary) species were found in all ternary systems.
Inmore basic medium, the ternary species were fragmented, therefore
generating ML(OH)3 and ML(OH)4 hydrolyzed binary species, which have in
turn greaterstability.
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