Síntese, caracterização e estudo termoanalítico de isonicotinatos de lantanídeos e ítrio no estado sólido
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Data
2018-11-23
Autores
Nunes, Wilhan Donizete Gonçalves
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O presente trabalho visa à síntese, caracterização e estudo termoanalítico dos isonicotinatos de lantânio(III), cério(III), praseodímio(III), neodímio(III), samário(III), európio(III), gadolínio(III), térbio(III), disprósio(III), hólmio(III), érbio(III), túlio(III), itérbio(III), lutécio(III) e ítrio(III) no estado sólido. A síntese foi realizada por precipitação, tendo como precursores o ácido isonicotínico, e os óxidos dos respectivos metais. A caracterização dos compostos obtidos foi realizada empregando-se métodos analíticos clássicos, e as técnicas de Termogravimetria e calorimetria exploratória diferencial simultânea (TG-DSC), espectroscopia de absorção na região do infravermelho (IV) com transformada de Fourier (FTIR), termogravimetria acoplada à espectroscopia de absorção na região do infravermelho (TG/FTIR), calorimetria exploratória diferencial (DSC), e difração de raios X pelo método do pó (DRXP). A partir dos dados das análises a estabilidade térmica, comportamento térmico, principais produtos gasosos liberados durante a decomposição térmica, estequiometria, quantidade e modo de interação das moléculas de água presentes, cristalinidade e modo de coordenação metal-ligante foram determinados. Os resultados foram ainda comparados com dados da literatura.
The present work aims at the synthesis, characterization and thermoanalytical study of isonicotinates of lanthanum (III), cerium (III), praseodymium (III), neodymium (III), samarium (III), europium (III), gadolinium (III), dysprosium (III), holmium (III), erbium (III), thulium (III), ytterbium (III), lutetium (III) and yttrium (III) solid. The synthesis was carried out by precipitation, having as precursors the isonicotinic acid, and the oxides of the respective metals. The characterization of the obtained compounds was carried out using classical analytical methods, and the techniques of thermogravimetry and simultaneous differential scanning calorimetry (TG-DSC), absorption spectroscopy in the infrared (IV) region with Fourier transform (FTIR), coupled thermogravimetry infrared absorption spectroscopy (TG / FTIR), differential scanning calorimetry (DSC), and X-ray diffraction by the powder method (XRD). From the analysis data the thermal stability, thermal behavior, main gaseous products released during thermal decomposition, stoichiometry, amount and mode of interaction of the water molecules present, crystallinity and mode of metal-bonding coordination were determined. The results were also compared with data from the literature.
The present work aims at the synthesis, characterization and thermoanalytical study of isonicotinates of lanthanum (III), cerium (III), praseodymium (III), neodymium (III), samarium (III), europium (III), gadolinium (III), dysprosium (III), holmium (III), erbium (III), thulium (III), ytterbium (III), lutetium (III) and yttrium (III) solid. The synthesis was carried out by precipitation, having as precursors the isonicotinic acid, and the oxides of the respective metals. The characterization of the obtained compounds was carried out using classical analytical methods, and the techniques of thermogravimetry and simultaneous differential scanning calorimetry (TG-DSC), absorption spectroscopy in the infrared (IV) region with Fourier transform (FTIR), coupled thermogravimetry infrared absorption spectroscopy (TG / FTIR), differential scanning calorimetry (DSC), and X-ray diffraction by the powder method (XRD). From the analysis data the thermal stability, thermal behavior, main gaseous products released during thermal decomposition, stoichiometry, amount and mode of interaction of the water molecules present, crystallinity and mode of metal-bonding coordination were determined. The results were also compared with data from the literature.
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Palavras-chave
Química analítica, Análise térmica, Termogravimetria, Metais de terras raras, Síntese inorgânica, Analytical chemistry, Thermal analysis, Thermogravimetry, Rare earth metals, Inorganic synthesis