Síntese mecanoquímica do cocristal de ácido salicílico com ácido nicotínico

• Autor(a) principal: Ferreira, Laura Teófilo [UNESP]
• Data de Publicação: 2017
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/155651; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-06-28/000887281.pdf
• topic: Cristalização; Acido salicilico; Estrutura quimica; Testes quimicos e reagentes; Niacina

The preliminary study of the selected reagents showed that the NCO does not undergo polymorphic transition during the grinding process, under the conditions adopted, however the SA presented structural alterations in the X-ray diffractograms, the DSC curve discarded the possibility of forming a polymorph of SA, however the direct test for Fe3+ indicated the presence of the ion in the milled sample, it was observed the disappearance of the phenol characteristic band (present in SA) in the FTIR spectrum, indicating the formation of a complex between SA and Fe3+. A screening was done using the salicylic acid and nicotinic acid APIs by means of the mechanochemical synthesis to try to obtain cocristais from these compounds. The X-ray diffraction patterns were efficient for the study of crystalline structures compounds. When comparing the diffractograms, it was observed that the NCO SA 1: 1 and 2: 1 systems were diffractograms sum of the API and coformador, indicating that there were no interactions between the compounds, however the 1: 2 system diffractogram showed evidence of obtaining cocristal. The FTIR technique provided important information on the sites of interaction between the molecules, showing that 1: 1 and 2: 1 NCO SA systems did not interact, and that the 1: 2 system interacted, confirming also the stoichiometry used in the synthesis. Thermal analysis techniques were essential to provide information on the thermal behavior of compounds and mixtures, indicating the formation of eutectic compounds in the 1: 1 and 2: 1 systems and confirming the obtaining of the cocrystal in the 1: 2 system by means of the DSC curves, the TG-DTA curves showed information on the thermal stability of these compounds and assisted in the analysis of the DSC curves