44 research outputs found

    Synthesis, characterization and thermal behaviour of solid 2-methoxycinnamylidenepyruvate of light trivalent lanthanides

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    Solid state Ln-2-MeO-CP compounds, where Ln stands for light trivalent lanthanides (La, Ce, Pr, Nd, Sm, Eu, Gd) and 2-MeO-CP is 2-methoxycinnamylidenepyruvate, were synthesized in this work. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, experimental and theoretical infrared spectroscopy and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information regarding the composition and stability of the isolated complexes

    Synthesis, characterization and thermal behaviour of solid 2-methoxycinnamylidenepyruvate of some bivalent metal ions in CO2 and N2 atmospheres

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    Compostos M-2-MeO-CP foram sintetizados no estado sólido, onde M representa os metais bivalentes (Mn(II), Fe(II), Co(II), Ni(II), Cu(II) e Zn(II)) e 2-MeO-CP é o 2-metoxicinamalpiruvato. Para estabelecer a estequiometria e estudar o comportamento térmico desses compostos foram utilizadas termogravimetria, análise térmica diferencial simultânea (TG-DTA), calorimetria exploratória diferencial (DSC), análise elementar e complexometria com EDTA. Os resultados foram concordantes com a fórmula geral: M(L)2∙H2O. em ambas as atmosferas a decomposição térmica ocorre em etapas consecutivas e é característica de cada composto. em atmosfera de CO2 os resíduos finais foram: Mn3O4, Fe3O4, Co3O4, NiO, Cu2O e ZnO, enquanto que em atmosfera de N2 a decomposição térmica ainda é observada até 1000 ºC.Solid State M-2-MeO-CP compounds, where M stands for bivalent metals (Mn, Fe, Co, Ni, Cu and Zn) and 2-MeO-CP is 2-methoxycinnamylidenepyruvate, were synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), elemental analysis and complexometry were used to establish the stoichiometry and to study the thermal behaviour of these compounds in CO2 and N2 atmospheres. The results were consistent with the general formula: M(L)2∙H2O. In both atmospheres (CO2, N2) the thermal decomposition occurs in consecutive steps which are characteristic of each compound. For CO2 atmosphere the final residues were: Mn3O4, Fe3O4, Co3O4, NiO, Cu2O and ZnO, while under N2 atmosphere the thermal decomposition is still observed at 1000 º C.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Synthesis, characterization and thermal behaviour of solid-state compounds of 4-methoxybenzoate with lanthanum (III) and trivalent lighter lanthanides

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    Compostos M ­ L foram sintetizados no estado sólido, onde M representa os íons trivalentes La, Ce, Pr, Nd e Sm, e L é o ânion 4 ­ metoxibenzoato. Esses compostos foram caracterizados e estudados, utilizando-se as técnicas de difração de raios x pelo método do pó, espectroscopia na região do infravermelho, complexometria, termogravimetria­análise térmica diferencial simultânea (TG­DTA) e DSC. Os resultados permitiram obter informações com respeito à estequiometria, desidratação, transformação polimórfica, ligação metal- ligante, comportamento térmico e decomposição térmica.Solid-state M-4-MeO-Bz compounds, where M stands for trivalent La, Ce, Pr, Nd and Sm and 4-MeO-Bz is 4-methoxybenzoate, have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information about the composition, dehydration, polymorphic transformation, ligand's denticity, thermal behaviour and thermal decomposition of the isolated compounds.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Solid-state compounds of 2-chlorobenzylidenepyruvate with some bivalent metal ions - Synthesis, characterization and thermal behaviour

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    Solid-state M-2-Cl-BP, where M stands for Mn, Fe, Co, Ni, Cu, Zn and Pb and 2-Cl-BP is 2-chlorobenzylidenepyruvate, have been synthesized. Thermogravimetry and derivative thermogravimetry (TG/DTG), simultaneous thermogravimetry and differential thermal analysis (TG-DTA), X-ray powder diffractometry, infrared spectroscopy, elemental analysis, and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information about the composition, dehydration, thermal stability and thermal decomposition of the isolated compounds

    Synthesis, characterization and thermal behaviour of solid-state compounds of 4-methoxybenzoate with some bivalent transition metal ions

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    Solid-state M-4-MeO-Bz compounds, where M stands for bivalent Mn, Co, Ni, Cu and Zn and 4-MeO-Bz is 4-methoxybenzoate, have been synthesized. Simultaneous thermogravimetry-differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy, elemental analysis and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to have information about the composition, dehydration, thermal stability and thermal decomposition of the isolated compounds. © 2005 Akadémiai Kiadó, Budapest

    Thermal studies of solid 2-methoxybenzylidenepyruvate of lighter trivalent lanthanides

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    Solid-state compounds with a general formula of LnL3· nH2O, where Ln stands for lighter trivalent lanthanides (lanthanum to samarium), L is 2-methoxybenzylidenepyruvate and n=1.5, 2, 2, 1.5 and 2, respectively, have been synthesized. On heating these compounds are decompose in two or three steps. They lose their hydration water in the first step and the thermal decomposition of the anhydrous compounds occurs with the formation of the respective oxide, CeO2, Pr6O11 and Ln 2O3 (Ln=La, Nd, Sm) as final residue. The dehydration enthalpies found for these compounds (La to Sm) were: 222.7, 163.6, 497.7, 513.9 and 715.4 kJ mol-1, respectively. © 2005 Akadémiai Kiadó, Budapest
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