Transition Metal Compounds
Mostrando 1-12 de 75 artigos, teses e dissertações.
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1. EVALUATION OF THE RELATIVE PROTECTION FACTOR OF ROSEMARY EXTRACT IN BIODIESEL IN THE PRESENCE OF TRANSITION METAL IONS
Biodiesel contains unsaturated methyl esters making it susceptible to oxidation reaction. Among the factors that cause oxidative instability is the contamination by transition metal ions that in small quantities catalyze the oxidation reaction. The objective of this work was to evaluate the relative protection factor of rosemary extract, in biodiesel, in the
Quím. Nova. Publicado em: 2020-09
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2. RAMAN STUDIES OF BIS(PHENYLTERPYRAZINE)IRON(II) AND SUPRAMOLECULAR SPECIES WITH PENTACYANIDOFERRATE(II) IONS
The chemistry and spectroscopy of the iron(II) phenylterpyrazine complex, [Fe(phtpz)2]2+, were investigated in comparison with the analogous phenylterpyridine species, Fe(phtpy)2]2+, and the results indicated a strong electronic delocalization on the Fe(II) terimine chromophore encompassing the lateral pyrazyl groups. The delocalized nature of the molecular
Quím. Nova. Publicado em: 05/12/2019
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3. In vitro Evaluation of Oxidative Stress Caused by Fine Particles (PM2.5) Exhausted from Heavy-Duty Vehicles Using Diesel/Biodiesel Blends under Real World Conditions
In this work, the redox activity of fine diesel/biodiesel particulate matter (PM2.5) was studied in order to approach its toxicity from reactive oxygen species, due to adverse effects it may cause to human health. The oxidative potential was measured by the dithiothreitol (DTT) assay in order to study the relative contribution of water-soluble transition met
J. Braz. Chem. Soc.. Publicado em: 2018-06
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4. ESTRATÉGIAS E MATERIAIS UTILIZADOS EM FOTOCATÁLISE HETEROGÊNEA PARA GERAÇÃO DE HIDROGÊNIO ATRAVÉS DA FOTÓLISE DA ÁGUA
Among the various technologies for the production of hydrogen fuel, heterogeneous photocatalysis is one of the most promising, especially with the use of semiconductors, notably TiO2. However, the use of TiO2 is limited by hindrances for the photolysis of water, such as wide bandgap, a less negative conduction band reduction potential as compared to that of
Quím. Nova. Publicado em: 2017-06
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5. Supramolecular Approach to Decorate Multi-Walled Carbon Nanotubes with Negatively Charged Iron(II) Complexes
Poly(4-vinylpyridine) (P4VP) and P4VP/pentacyanoferrate(II) metallopolymer were used to suspend up to 1 mg mL-1 of multi-walled carbon nanotubes (MWCNT) in ethanol/water mixtures, providing noncolavent decoration of MWCNT with electroactive iron complex. The major interaction between polymer side chains and nanotubes is via π-π stacking, rather than charge
J. Braz. Chem. Soc.. Publicado em: 2017-01
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6. Ni(II), Cu(II), AND Zn(II) COMPLEXES DERIVED FROM A NEW SCHIFF BASE 2-((Z)-(3-METHYLPYRIDIN-2- YLEIMINO)METHYL)PHENOL AND SYNTHESIS OF NANO SIZED METAL OXIDE PARTICLES FROM THESE COMPOUNDS
Synthesis, spectral identification, and magnetic properties of three complexes of Ni(II), Cu(II), and Zn(II) are described. All three compounds have the general formula [M(L)2(H2O)2], where L = deprotonated phenol in the Schiff base 2-((z)-(3-methylpyridin-2-yleimino)methyl)phenol. The three complexes were synthesized in a one-step synthesis and characterize
Quím. Nova. Publicado em: 2015-11
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7. Mecanismos moleculares da ação tóxica pró-oxidante de 1,4-diamino-2-butanona, um análogo de putrescina, sobre células de mamíferos e Trypanosoma cruzi / The Molecular mechanisms of pro-oxidant activity of 1,4-diamino-2-butanone, a putrescine analogue, to mammalian cells and Trypanosoma cruzi
α-Aminocarbonyl componds such as 5-aminolevunilic acid (ALA) and aminoacetone (AA) have been shown to exhibit pro-oxidant properties. These compounds undergo phosphate-catalyzed enolization in physiological pH and subsequent aerobic oxidation, yielding reactive oxygen species, NH4+ ions and an α-oxoaldehyde highly cytotoxic. The α-aminoketone 1
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/06/2012
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8. Crescimento e propriedades vibracionais de cristais a base de Ãxidos / Growth and Vibrational Properties of Oxide Crystals
In this work we used different experimental techniques to study four different series of inorganic oxide crystals, namely: (i) congruent lithium isotope niobate (C7LN), (ii) rare-earth doped mixed vanadates ((Nd,Yb):YxGd1-x(VO4)); (iii) alkali metal doped and pure calcium barium niobates (CaxBa1-xNb2O6); and (iv) potassium tantalite niobate (KTa1-xNbxO3). Be
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/03/2012
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9. Evaluation of toxic effects with transition metal ions, EDTA, SBTI and acrylic polymers on Aedes aegypti (L., 1762) (Culicidae) and Artemia salina (Artemidae)
This work aimed to evaluate the toxicity of some insecticides compounds on Aedes aegypti and Artemia salina larvae. Bioassays were carried out to evaluate the toxic effect after of 24 and 72 h using the compounds or associations. The LC10, LC50 and LC90 values were obtained and utilized for toxicity comparations. For Ae. aegypti, LC50 were 32.65 mg L-1 in 24
Brazilian Archives of Biology and Technology. Publicado em: 2011-06
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10. Princípios da determinação de íons em amostras por eletroforese capilar.
ABSTRACT: This work presents theory and applications in capillary electrophoresis. This technique is a powerful tool representing a large saving in chemicals (0.5 to 4 nL s-1 flux), samples (1 to 100 nL), and method development time. In addition, this work pictures applications such as separation and determination of analytical compounds. Recent reviews were
Planaltina. Publicado em: 2011
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11. Investigation of structural, electronic and magnetica properties of Ca2-xLaxFelrO6, Sr2-xLaxFelrO6 e TbMnO3 oxides / Investigação as propriedades estruturais, eletronicas e magneticas dos oxidos Ca2-xLaxFelrO6, Sr2-xLaxFelrO6 e TbMnO3
For many decades the transition metal oxides are subject of great scientific interest because of the wide variety of interesting physical properties and their potential technological applications. More recently, for example, oxides of transition metals with multiferroic properties have been considered as potential magneto-electronic devices. Many transition
Publicado em: 2010
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12. Selective hydrogenation of 1,3-butadiene by transition metal compounds immobilized in 1-butyl-3-methyl imidazolium room temperature ionic liquids
Os complexos [Co(acac)2], [Co(acac)3], [Fe(acac)3] e [Ni(acac)2] (acac = acetilacetonato) dissolvidos em tetrafluoroborato de 1-butil-3-metilimidazônio (1), trifluorometanosulfonato de 1- butil-3-metilimidazólio (2) ou hexafluorofosfato de 1-butil-3-metilimidazólio (3), catalisam a hidrogenação de 1,3-butadieno em butenos em sistema catalítico tipicame
Publicado em: 2010