Síntese, caracterização e estudo do comportamento térmico dos 2-clorobenzalpiruvatos de lantânio (III), lantanídios (III) e de ítrio (III), no estado sólido

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Síntese, caracterização e estudo termoanalítico dos mandelatos de lantanídeos(III), exceto o promécio, e de ítrio(III) no estado sólido

Pós-graduação em Química - IQ

Síntese de cerâmicas ferroelétricas de PLZT–análise composicional e mecanismos de vacâncias

Pós-graduação em Ciência dos Materiais - FEIS

Thermal investigation and infrared evolved gas analysis of solid trivalent lanthanide and yttrium alpha-hydroxyisobutyrates in N-2 and CO2 atmospheres

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência do lantânio nas propriedades estruturais do SrSnO3

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Síntese e caracterização de complexos de naproxeno com lantanídeos (III) e ítrio (III) no estado sólido com exceção do promécio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Propriedades estruturais e espectroscópicas de complexos de difenilfosfinatos dos sistemas ternários 'LA'-'CE'-'EU'/'LA'-CE'-'TB'

Pós-graduação em Química - IQ

Síntese e caracterização de complexos de cetoprofeno com lantanídeos (III) e Ítirio (III) no estado sólido com exceção do promécio

Solid-state compounds of general formula LnL3.nH2O, in wich Ln represents lanthanum, lanthanides and yttrium, L is ketoprofen, and n = 0,5 (Pr, Sm, Tb), 1 (La, Eu, Dy, Ho, Er, Tm, Lu) e 1,5 (Ce, Nd, Gd, Yb, Y) were synthesized. Simultaneous thermogravimetry-differential analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy and EDTA complexometry were employed to characterize these compounds. The TG-DTA and DSC curves provided information concerning the thermal behaviour and thermal decomposition of synthesized compounds. The experimental and theoretical infrared spectroscopic data suggested that ketoprofen acts as a bidentate ligand towards trivalent lanthanides and yttrium (III)

Síntese e caracterização do complexo de lantânio (III) e indometacina no estado sólido

In this study, the drug indomethacin, a non-steroidal anti-inflammatory indoleacetic acid derivative and the complex of indomethacin and lanthanum (III) in solid form were synthesized and characterized by Thermogravimetry (TGA), Differential Thermal Analysis (DTA), Differential Scanning Calorimetry (DSC) and powder X-ray diffractometry (XRD), infrared vibrational spectroscopy by diffuse reflectance (FTIR) and complexometric titration with EDTA. With the TG curves it was possible to determine the stoichiometry of the complex as La(Ind)3·3.5H2O where Ind is the drug indomethacin. The result of thermal analyzes provided information on the thermal stability, enthalpy of dehydration and thermal behavior of the compounds. The infrared spectrum and with the aid of theoretical calculations suggests that the indomethacin is coordinated by the carboxylate group in the bidentate mode

Estudo termoanalítico de complexos do fármaco Ibuprofeno com lantanídeos (III) leves no estado sólido com exceção do promécio

This Final Paper had as it main goal to make a thermoanalytical study of lighter trivalent lanthanides (Lanthanum, Cerium, Praseodymium, Neodymium, Samarium and Europium) with the Ibuprofen ligand (nonsteroidal anti-inflammatory) that have a general formula LnL3.nH2O, on solid state, where Ln are the Lanthanides, L is the Ibuprofen ligand and n = number of water molecules of hydration that went from 1,0 to all the compounds. In order to characterize this compounds, it has been used the thermoanalytical techniques TG-DTA (thermogravimetry - Diferential Thermal Analysis) and DSC (Diferential Scanning Calorimetry), Fourier transformed infrared spectroscopy (FTIR) and complexometric titration with EDTA. Through the TG-DTA technique, it has been possible to set the thermal stability of the compounds, the number of thermal decomposition steps and temperatures that ocurred that also provided stoichiometry to the synthesized compounds. The DSC technique has shown the enthalpy of dehydration of the samarium and europium compounds, it was not possible to see it in the other compounds due to a endothermic peak on the DSC curve not being formed. In the case of neodymium, a thermal event ocurred, in which it could be a oxidative decarboxylation right after the dehydration. The infrared was utilised to study the carboxilate groups streches, and so, suggest a ligand metals compound coordination, that to this present paper has been a bidentade bridged coordenation. At last, the complexometric tritation was used to very the ammount of metal present in each compound, and so, verify if the proposed stoichiometry was according to the theory

Inorganic elemental analysis and identification of residual monomers released from different glass ionomer cements in cell culture medium

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Studies on double selenates. XI. Thermal decomposition of lanthanides of the ceric group and lithium double selenates

A previous communication [1] described the preparation of the double selenates of lanthanum and the alkali metals; the La-Li compound has the formula La2(SeO4)3 · Li2SeO4 · 8H2O. Subsequent reports [2-4] have shown that it was not possible to prepare the Ce-Li, Pr-Li, Nd-Li and Sm-Li double selenates, using the same method [1]. It was possible to isolate the double selenates of all the cerie group lanthanides and lithium not previously described and, also, a La-Li double selenate having a different stoichiometry, using a modified preparation technique. © 1990.

IR-visible upconversion and thermal effects in Pr3+/Yb3+-codoped Ga2O3 : La2S3 chalcogenide glasses

IR-visible upconversion fluorescence spectroscopy and thermal effects in pr(3+)/Yb3+-codoped Ga2O3:La2S3 chalcogenide glasses excited at 1.064 mum is reported. Intense visible upconversion emission in the wavelength region of 480-680 nm peaked around 500, 550, 620 and 660 nm is observed. Upconversion excitation of the Pr3+ excited-state visible emitting levels is achieved by st combination of phonon-assisted absorption, energy-transfer and phonon-assisted excited-state absorption processes. A threefold upconversion emission enhancement induced by thermal effects when the codoped sample was heated in the temperature range of 20-200 degreesC is demonstrated. The thermal-induced enhancement is attributed to a multiphonon-assisted anti-Stokes process which takes place in the excitation of the ytterbium and excited-state absorption of the praseodymium. The thermal effect is modelled by conventional rate equations considering temperature-dependent effective absorption cross-sections for the F-2(7/2)-F-2(5/2) ytterbium transition and (1)G(4)-P-3(0) praseadymium excited-state absorption, and it is shown to agree very well with experimental results. Frequency upconversion in singly Pr3+-doped samples pumped at 836 nm and 1.064 mum in a two-beam configuration is also examined.

Thermal and crystalographic studies of mixture La2O3-SrO prepared via reaction in the solid state

The compound obtained via state solid reaction of the La2O3 and SrO oxides and expose the room atmosphere shows the crystallographic data of the compound reported as La2SrOx. However, thermogravimetric, differential thermal analysis and XRD with controlled temperature indicated that the stoichiometry of the compound is 2La(OH)(3)-SrCO3, which structural parameters were determined by using the Rietveld method. It was verified that when the compound exposed at room atmosphere, the mixture oxide absorbs H2O and CO2 producing hydroxide and carbonate of lanthanum and strontium, respectively, which thermal decomposition occurs by the same steps, producing the La2O3-SrO.