Título: | MAGNETIC AND PHOTOLUMINESCENCE STUDIES OF COORDINATION COMPOUNDS CONTAINING CARBOXYLATO AND/OR N-DONOR LIGANDS COMPLEXED TO TRANSITION OR LANTHANIDE METAL IONS | ||||||||||||
Autor: |
HENRIQUE VON PRESSENTIN HOLLAUER |
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Colaborador(es): |
LIVIA BATISTA LOPES ESCOBAR - Orientador |
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Catalogação: | 13/JAN/2025 | Língua(s): | ENGLISH - UNITED STATES |
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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=69112&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=69112&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.69112 | ||||||||||||
Resumo: | |||||||||||||
Molecular magnetism has created a lot of interest due to its possible
application in components of electronic materials. These types of materials can
be created through coordination compounds such as coordination polymers,
which have the capacity to be multifunctional materials. In this work, we
synthesized a total of 11 new complexes organized in two systems that differ
according to the composition of materials. The first system utilized the mixture
of polycarboxylate ligand BTB and N-donor ligand such as phen and dmdpy to
evaluate the influence of these auxiliary ligands in the complexes structure and
properties. The family utilizing phen as auxiliary ligand generated two isomorph
1D coordination polymers with Cu(2+) and Co(2+) as metal ions. EPR measurements
for Cu(2+) polymer showed almost no magnetic interactions between metal ions.
Due to both CPs being isomorph, the same small magnetic interactions were
expected for Co(2+) CP, which is an indicative of possible magnetic molecule
behavior due to cobalt strong ZFS. Out-of-Phase magnetic susceptibility
measurement showed the nanomagnet behavior. A relaxation time of yield point stress = 5.52(4)
× 10(-7)
s and energy barrier of 12.1(3) K were determined for this complex. The
change of N-donor ligand from phen to dmdpy resulted in a pentacoordinated
Cu(2+) dimer, however, since the divergent ligand for both families was the same,
the small interaction between the copper(II) ions was obtained, as evidenced by
EPR and magnetization measurements.
The second system presents Ln(3+) ions with Coumarin-3-carboxylic acid
as the organic ligand, where two different families were obtained by changing
the proportion of Ln ions and ligand. First family 1D CP were obtained with both
components with the same proportion. Magnetocaloric studies were conducted
for the Gd(3+) and the obtained maximum magnetic entropy value was smaller than the expected value.
For the Tb(3+) and Dy(3+) CPs displayed potential as nanomagnets due to the signal
obtained in dynamic magnetic measurements. Photoluminescent studies for Eu(3+)
and Tb(3+) CPs were conducted, where 0.30 ± 0.05 ms and 0.13 0.05 ms emission
lifetime was estimated. The second family obtained had a Ln(3+) and 3-HCCA
proportion of 1:3, and resulted in a 1D coordination polymer, where the
extension of the polymeric chain had the same mechanism. Photoluminescent
studies for Eu(3+) and Tb(3+) CPs were conducted, where an increase in the emission
lifetime from 0.30 mais ou menos 0.05 ms to 0.45 0.05 ms for Eu(3+) derivate was observed due
to the removal of one H2O molecule coordinated to the europium ion.
This work resulted, at the time of this dissertation, in the publication of
two scientific papers, as well as a submitted paper that is currently under review.
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