Ethylenediamine
Mostrando 25-36 de 168 artigos, teses e dissertações.
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25. Síntese de complexo ferro(II)-nitrogênio: abordagem dos conceitos de reatividade e retro-doação para alunos de graduação em química
There has been a considerable interest in coordination complexes of molecular nitrogen (N2), partly due to a possible relationship between such complexes and the nitrogen activation process in nature. The present paper describes the synthesis and infrared spectroscopic characterization of an iron-nitrogen derivative with ethylenediamine-N,N,N',N'-tetraacetat
Química Nova. Publicado em: 2007-06
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26. Preparação de redes modificadas de poli(dimetilsiloxano) com ion piridinio ou etilenodiamina : estudo da adsorção de ions metalicos em etanolico / Preparation of modified poly(dimethylsiloxane) network with pyridine ion or ethylenediamine : study of metalic ion adsoption from ethanol solution
In this work elastomeric polymeric networks based on poly(dimethilsiloxane) PDMS, modified with pyridine ion or ethylenediamine, were prepared. These materials were characterized by infrared spectrometry, thermogravimetric analysis, differential scanning calorimetry and nuclear magnetic resonance (NMR) of Si and C. The results showed that both materials pres
Publicado em: 2007
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27. Nanocomposites and nanostructures of II-VI and IV-VI semiconductors / Nanocompositos e nanoestruturas de semicondutores das familias II-VI e IV-VI
The development of nanostructures and their applications constitute one of the most exciting scientific areas. A great number of studies in this area concern the preparation methods. Generally, they are classified in physical and chemical methods. The former class is based on molecular beam and lithography techniques, while the latter involves chemical react
Publicado em: 2007
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28. Desenvolvimento e otimização de metodologias para a determinação de nitrogênio / Development and optimization of methodologies to the nitrogen determination
The determination of inorganic and organic nitrogen is an interesting subject in the analysis of biological samples: soil, water and foods. These analyses are motivated by the losses of nitrogen of the ground to freatic sheets and marine ecosystems, causing eutrofization, and by the elevated toxicity of these composites, in human, animals and vegetables. Thi
Publicado em: 2007
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29. Synthesis and characterization of platinum(II) complexes from trifluoromethyl phenylenediamine, picoline and N-benzyl ethylenediamine derivatives
Este trabalho descreve a síntese e a caracterização de onze novos complexos de platina(II), contendo como ligantes derivados da 1,2-fenilenodiamina, da N-benzil etilenodiamina, e da 2- ou 4-picolina. Os complexos foram preparados em rendimentos satisfatórios pela reação dos ligantes com K2[PtCl4]. É descrita também a atividade citotóxica de um dos c
Journal of the Brazilian Chemical Society. Publicado em: 2006-12
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30. Polypropylene grafted with glycidyl methacrylate using supercritical CO2 medium
Films of polypropylene (PP) were grafted with glycidil methacrylate (GMA) using supercritical CO2 as swelling agent and solvent. Different pressures and temperatures were used to study their effects on the soaking and grafting process. FTIR results showed signals at 1726 and 1640 cm-1, assigned to C=O and C=C (after the soaking process), and a decreased sign
Brazilian Journal of Chemical Engineering. Publicado em: 2006-06
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31. Estudos Cinéticos da aquação do trans-[Co(en)2Cl2]Cl
The trans-dichlorobis(ethylenediamine)cobalt(III) chloride was synthesized in an undergraduate laboratory and its aquation reaction was carried out at different temperatures. This reaction follows pseudo-first-order kinetics and the rate constants, determined at 25, 35, 45, 55 and 70 º C, are 1.44 x 10-3; 5.14 x 10-3; 1.48 x 10-2; 4.21 x 10-2 and 2.21 x 10-
Química Nova. Publicado em: 2006-04
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32. Aplicação e modificação química da sílica gel obtida de areia
The silica gel was obtained from sand and its surface was modified with POCl3 to produce Si-Cl bonds on the silica surface. Ethylenediamine was covalently bonded onto the chlorinated silica surface. The adsorption of the chlorides of divalent cobalt, nickel and copper was qualitatively studied to show that the bonding of ethylenediamine onto the silica gel s
Química Nova. Publicado em: 2005-06
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33. Química de complexos de (etilenodiaminatetraacetato)rutenato(III/II)
This paper provides a survey of general aspects involved in the coordination chemistry of low-valent (mainly +III,+II), low-spin (d p5,d p6) ruthenium ions with ethylenediamine-N,N,N',N'-tetraacetate (edta) and their substituted derivatives. The topics covered herein include structure, reactivity, kinetics, thermodynamics, electrochemistry and spectroscopy.
Química Nova. Publicado em: 2004-02
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34. Tailoring activated carbon by surface chemical modification with O, S, and N containing molecules
In this work the surface of activated carbon was chemically modified in order to introduce O, S and N containing groups. The activated carbon surface was selectively oxidized with concentrated HNO3 under controlled conditions. Characterization by thermogravimetric analyses, infrared spectroscopy and NaOH titration suggested the formation of mainly -COOH and
Materials Research. Publicado em: 2003-06
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35. Novos agentes sililantes derivados de precursor epoxido na imobilização e sintese de silica mesoporosa
The silylant precursor agent 3-glycidoxypropyltrimethoxisilane was covalently anchored onto the silica gel surface through homogeneous and heterogeneous routes. Ethylenediamine, 1,3-diaminepropane and 2-aminemethylpyridine molecules were incorporated on the epoxide group in order to explore the properties of these basic nitrogen atoms in coordinating some di
Publicado em: 2003
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36. Enantioselective synthesis of aziridines using asymmetric transfer hydrogenation as a precursor for chiral derivatives used as bonding agent for rocket solid propellants
A rapid, expedient and enantioselective method for the synthesis of beta-hydroxy amines and monosubstituted aziridines in up to 99% e.e., via asymmetric transfer hydrogenation of a-amino ketones and cyclisation through treatment with tosyl chloride and base, is described. (1R,2R)-N-(para-toluenesulfonyl)-1,2-ethylenediamine with formic acid has been utilised
Química Nova. Publicado em: 2002-11