S?ntese e caracteriza??o de novos compostos de coordena??o contendo um ligante piraz?lico funcionalizado.

• Ano de defesa: 2019
• Autor(a) principal: Soares, Iuri Cardoso
• Orientador(a): Guedes, Guilherme Pereira
• Banca de defesa: Guedes, Guilherme Pereira , Cruz, Antonio Gerson Bernardo da , Miranda, Fabio da Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural do Rio de Janeiro
• Programa de Pós-Graduação: Programa de P?s-Gradua??o em Qu?mica
• Departamento: Instituto de Qu?mica
• País: Brasil
• Palavras-chave em Português: compostos de coordena??o; pirazol; single-ion magnet
• Palavras-chave em Inglês: coordination compounds; pyrazole; single-ion magnet
• Área do conhecimento CNPq: Qu?mica
• Link de acesso: https://tede.ufrrj.br/jspui/handle/jspui/5216

This work describes five new coordination compounds containing CoII, NiII and CuII, a functionalized pyrazole spacer KL (5-amino-1-phenyl-1H-pyrazole-4-carboxylate) with one of the amines as auxiliary ligand: 2,2'-bipyridine (2,2'-bipy), 4,4'-bipyridine (4,4'-bipy) or 1,10'-phenanthroline (phen). The synthesis of KL was performed in three reactional steps, in which one the precursors were characterized by infrared spectroscopy, melting point, 1H-NMR and 13C-NMR. Furthermore, the compound EL was characterized by single-crystal x-ray diffraction. After the formation of the KL, an electrophilic susceptibility map was generated using DFT calculations, which evidenced the tendency of the ligand to coordinate in different ways depending on stoichiometric, energetic and/or entropic factors. Based on this knowledge the synthesis of the coordination compounds was carried out using synthetic routes to explore all KL coordination sites. Then, a new family of coordination polymers with molecular formula 1?[M(L)2(4,4?-bipy)2(H2O)2]n (M= CoII, NiII and CuII,) (1-3), a polymer of 1?[CuII2(L)2(phen)2]n(ClO4)2 (4) and a [CuII2(L)(2,2?-bipy)4](ClO4)3 (5), were obtained by slow solvent diffusion. These compounds were characterized by elemental analysis, infrared spectroscopy and single-crystal X-ray diffraction. In addition, compounds 3, 4 and 5 were studied by electronic paramagnetic resonance (EPR). Magnetic measurements in DC and AC mode for 1 were performed and shows slow relaxation of magnetization. The energy barrier to reversal of the magnetization of 1 was one of the largest reported for cobalt (II)-based coordination polymers.