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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
Instituição: PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO - PUC-RIO
Colaborador(es):  LIVIA BATISTA LOPES ESCOBAR - ADVISOR
Nº do Conteudo: 69112
Catalogação:  13/01/2025 Liberação: 14/10/2025 Idioma(s):  ENGLISH - UNITED STATES
Tipo:  TEXT Subtipo:  THESIS
Natureza:  SCHOLARLY PUBLICATION
Nota:  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.
Referência [pt]:  https://www.maxwell.vrac.puc-rio.br/colecao.php?strSecao=resultado&nrSeq=69112&idi=1
Referência [en]:  https://www.maxwell.vrac.puc-rio.br/colecao.php?strSecao=resultado&nrSeq=69112&idi=2
Referência 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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