Bromides
Mostrando 1-12 de 25 artigos, teses e dissertações.
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1. Structural Parameters of Lamellar Phases Formed by the Self-Assembly of Dialkyldimethylammonium Bromides in Aqueous Solution
Phase behavior of didodecyl and dioctadecydimethylammonium bromide (DDAB and DODAB) in water was studied using X-ray techniques, differential scanning calorimetry and deuterium nuclear magnetic resonance measurements. Both surfactants self-assemble into lamellar liquid crystalline, either Lα (fluid) and Lβ (gel), phases. The gel-to-fluid phase transition t
J. Braz. Chem. Soc.. Publicado em: 2016-02
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2. Tribromoisocyanuric acid/triphenylphosphine: a new system for conversion of alcohols into alkyl bromides
Foi desenvolvido um método fácil e eficiente para a conversão de alcoóis em brometos de alquila em meio neutro, utilizando ácido tribromoisocianúrico e trifenilfosfina (razão molar 1,0:0,7:2,0, álcool/ácido tribromoisocianúrico/trifenilfosfina) em diclorometano à temperatura ambiente. Esse método pode ser aplicado para a conversão de alcoóis pr
J. Braz. Chem. Soc.. Publicado em: 2014-05
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3. Pd-catalyzed Heck reactions of aryl bromides with 1,2-diarylethenes
Um sistema catalítico composto por Pd(OAc)2 e P(o-tol)3 foi aplicado na reação de Heck entre brometos de arila e diariletenos. Utilizando-se K2CO3 como base e DMF como solvente, olefinas triarilsubstituídas foram obtidas com rendimentos de bons a excelentes. Brometos de arila com substituintes eletroretiradores foram menos ativos para a reação de acopl
Journal of the Brazilian Chemical Society. Publicado em: 2011-07
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4. Evaluation of the influence of base and alkyl bromide on synthesis of pyrazinoic acid esters through fatorial design
Pyrazinoic acid esters have been synthesized as prodrugs of pyrazinoic acid. In the literature, its preparation is reported through the reaction of pyrazinoyl chloride with alcohols and the reaction with DCC/DMAP. In this work, it is reported a 2² factorial design to evaluate the preparation of these esters through the substitution of alkyl bromides with ca
Química Nova. Publicado em: 2009
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5. A highly efficient and general method for the preparation of (Z)-allylic bromides derived from Morita-Baylis-Hillman adducts
(Z)-2-(Bromometil)-2-alcenoatos são importantes intermediários sintéticos e foram preparados de forma simples e prática pelo tratamento de α-metileno-β-hidroxiésteres (produtos da reação de Morita-Baylis-Hillman) com LiBr/H2SO4 em acetonitrila à temperatura ambiente. Além de fornecer altos rendimentos e de tolerar a presença de diversos grupos fu
Journal of the Brazilian Chemical Society. Publicado em: 2009
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6. Estudos de formação e remoção de subprodutos de desinfecção (SPDS) em aguas contendo acidos humicols quando sumetidas a dioxido de cloro / Studies of formation and remotion of disinfection by products (DBP), generated by the oxidation of solutions containing humic substances throught the use of chlorine dioxide
The objective of the present research was to analyze the formation of disinfection by products (DPB), generated by the oxidation of solutions containing humic substances with the addition of bromide ions through the use of chlorine dioxide, isolated or associated with free chlorine in different concentrations and reaction times. The technique of gaseous chro
Publicado em: 2007
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7. A fluorescence probe study of gemini surfactants in aqueous solution: a comparison between n-2-n and n-6-n series of the alkanediyl-a,w-bis (dimethylalkylammonium bromides)
Two series of alkanediyl-a,w-bis (dimethylalkylammonium bromide (n-2-n and n-6-n; n=8, 10,12, and 16) have been synthesized and their micelles properties studied in aqueous solution using pyrene, pyrenecarboxaldehyde (PCA) and 1,8 anilinonaphtalene sulfonic acid sodium salt (ANS) as fluorescent probes. The micelles from these surfactants have been characteri
Eclética Química. Publicado em: 2007
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8. Analise do esmalte dental bovino ao redor de restaurações com sistemas adesivos/composito submetido a desafios cariogenicos in vitro e in situ / Analysis of bovine dental enamel around restorations with adhesives systems/composites submitted to a cariogenic challenge in vitro and in situ
Componentes anticariogênicos e antibacterianos como fluoreto (F-) e brometo (Br -) têm sido introduzidos nos sistemas adesivos na tentativa de melhorar a longevidade clínica das restaurações. No entanto, estes componentes não foram avaliados frente a altos desafios cariogênicos. O objetivo deste estudo foi avaliar o efeito destes novos adesivos no esm
Publicado em: 2006
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9. Formação e remoção de trihalometanos em aguas de abastecimento utilizando permanganato de potassio e carvão ativado em po / Trihalomethane formation and remotion in drinking water using potassium permanganate and powdered activated carbon
The present research had for objective to analyze the formation of THM through the use of potassium permanganate, isolated or associate with free chlorine, in the process of pre-oxidation, and, in a second stage, to evaluate the removal efficiency of these by-products through the adsorption in powdered activated carbon followed by conventional treatment. The
Publicado em: 2005
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10. Investigação calorimetrica da interação entre poli (N-isopropilacrilamida) e surfatantes ionicos / Calorimetric investigation of the interaction of poly (N-isopropylacrylamide) and ionic surfactants
The interaction of poly(N-isopropylacrylamide), PNIPAM, with an anionic (SDS) and three cationic (dodecyl and hexadecyltrimethylammonium bromides, DTAB and CTAB, and dodecylammonium chloride, DAC) surfactants has been studied using isothermal titration calorimetry and within a temperature range between 17 and 29°C. The high sensitivity of this technique all
Publicado em: 2004
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11. SÃntese e avaliaÃÃo da atividade biolÃgica de novos derivados acridino-tiazolidÃnicos e acridino-imidazolidÃnicos / SÃntese e avaliaÃÃo da atividade biolÃgica de novos derivados acridino-tiazolidÃnicos e acridino-imidazolidÃnicos
The acridines compounds present an ample variety of biological effect that can be attributed, in its great majority, its ability to bind the DNA, intercalating themselves it between the pairs of basis and blocking the action of topoisomerases I and II. In literature, compounds possessing the acridine ring are distinguished for presenting activities antimalar
Publicado em: 2003
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12. Hydrobromination of alkenes with PBr3/SiO2: a simple and efficient regiospecific preparation of alkyl bromides
A reação de diversos alquenos com 0,4 equiv. mol de PBr3/SiO2 em diclorometano à temperatura ambiente forneceu os brometos de alquila com regiospecificidade Markovnikov em 50 - 100% de rendimento e tempos curtos de reação. O isopreno a - 8 °C nestas mesmas condições forneceu somente o 1-bromo-3-metil-2-buteno em 54%
Journal of the Brazilian Chemical Society. Publicado em: 2001-10