Chromium Complexes
Mostrando 1-12 de 24 artigos, teses e dissertações.
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1. Synthesis, Characterization and Antimicrobial Activities of Copper, Nickel, Cobalt, Chromium Complexes Derived from (Z)-4-Fluoro-N-(2,7-dimethylhept-6-enylidene) benzenamine
Melonal is a relatively unexplored ingredient in the field of chemistry with excellent sensory properties. The synthesis and characterization of novel transition 3d metal complexes of copper(II), nickel(II), cobalt(II) and chromium(III) involving the Schiff base of melonal were explored to examine their biological activity. Characterization of the complexes
J. Braz. Chem. Soc.. Publicado em: 2017-05
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2. Synthesis, Characterization and Ethylene Oligomerization Studies of Chromium Complexes Bearing Imino-Furfural Ligands
Uma série de complexos de cromo(III) contendo ligantes imina-furfural (Cr1-Cr4) foram sintetizados e caracterizados por espectrometria de massas de alta resolução (HRMS). Todos os pré-catalisadores de cromo, ativados com metilaluminoxano (MAO), apresentaram atividade moderada na oligomerização do etileno [frequência de rotação (TOF) = 11.800-23.200
J. Braz. Chem. Soc.. Publicado em: 2014-12
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3. Caracterização da resistência à corrosão de ligas de alumínio após tratamentos alternativos à cromatização, com e sem revestimento orgânico / Characterization of the corrosion resistance of aluminum alloys after alternative treatmentes the chromate, with and without organic coating
In this study, the protective properties provided by new surface treatments for aluminum aiming the replacement of treatments that are harmful to the environment and human health, have been evaluated. The following treatments were investigated: passivation in solution with trivalent chromium ions, surface modification with self assembling molecules (SAM), im
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/03/2011
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4. Substituted tridentate pyrazolyl ligands for chromium and nickel-catalyzed ethylene oligomerization reactions: effect of auxiliary ligand on activity and selectivity
Dois novos complexos de cromo(III) contendo ligantes tridentados [CrCl3(L)] (1a, L = bis[2-(3-fenil-1-pirazol)etil)]amina; 2a, L = bis[2-(3-metil-5-fenil-l-pirazol)etil]sulfeto) foram preparados e caracterizados por análise elementar. Após ativação com metilaluminoxano (MAO), estes pré-catalisadores mostraram altas frequências de rotação nas reaçõe
Publicado em: 2011
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5. Novel catalyst systems based on Ni(II), Ti(IV), and Cr(III) complexes for oligo-and polymerization of ethylene
The complex of Brookhart Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6- diisopropylphenyl)-acenaphthenediimine) has been characterized after impregnation on silica (S1) and MAO-modified silicas (4.0, 8.0 and 23.0 wts.% Al/SiO2 called S2, S3 and S4, respectively). The treatment of these heterogeneous systems with MAO produces some active catalysts for the p
Publicado em: 2007
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6. Estudo das forças motrizes que regem a partição dos complexos [Fe(CN)5NO]2- e [Cr(CN)5NO]3- em SABs formados por poli(óxido de etileno) e sulfatos / Study of drivig forces partitioning behavior [Fe(CN)5NO]2- and [Cr(CN)5NO]3- complexes in Poli(ethylene oxide) and sulphates ATPS
In this dissertation a critical analysis in the area of partitioning ions in aqueous two phase systems (ATPS) was done, exposing some models that explain the distribution of those molecules in the phases. In a second study, data of phase diagram formed by poly (ethylene oxide) of molar mass 4000 g mol-1 (PEO 4000) and sulphate zinc at 298 K was obtained. It
Publicado em: 2006
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7. Geology and metallogenetic potential of the anorthositic-leucogabbroic Lagoa da Vaca Complex, Curaça, Bahia State, Brazil / Geologia e potencial metalogenetico do complexo anortositico-leucogabroico de Lagoa da Vaca, municipio de Curaça, Bahia
The complex is one of the three litho-structural domains mapped (central domain), and has an outcrop width of 3 kilometers. It is made up mostly of north-south-trending layers of anorthositic, meta-leucogabbroic, meta-gabbroic and ultramafic compositions. Ultramafic rocks of unknown stratigraphic relations, vz. peridotite and amphibole meta-peridotite, were
Publicado em: 2006
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8. AC electrical conductivity of Cr-doped polyaniline/poly(vinyl alcohol) blends
Polyaniline (PANI) and their charge transfer complexes are engineering materials that continue to attract considerable attention from engineers due to their unique electrochemical behavior, environmental stability and high degree of processability. Extensive works on the preparation of electrically conductive PANI blends containing a polymeric matrix having
Brazilian Journal of Physics. Publicado em: 2004-06
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9. "Spectrophotometric study of chromium(III)/azide system and your analytical application". / "Estudo espectrofotométrico do sistema crômio(III)/azoteto e seu aproveitamento analítico".
Na área de Química, uma das linhas mais tradicionais de pesquisa envolve o estudo de formação de complexos. Estes trabalhos são realizados de modo sistemático em nossos laboratórios, geralmente envolvendo cátions de metais de transição com vários ligantes (haletos, pseudo-haletos e carboxilatos). A intensa coloração desenvolvida pela maioria des
Publicado em: 2004
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10. On the Nature of Sandwiched Chromium Complexes in Exchanged alpha-Zirconium Phosphate
Layered alpha-zirconium hydrogenphosphate monohydrate was prepared by direct precipitation, exchanged with n-propylamine and then by chromium aquacomplexes. The solids were characterized by X-ray diffraction, mass spectrometry, infrared and UV-Visible spectroscopy. The results suggest that monomer complexes form extended, hydrogen bonded, sandwiched monolaye
Materials Research. Publicado em: 2002-10
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11. O impacto do crômio nos sistemas biológicos
The impact of biological chromium's activity may be beneficial or not. This review presents the most relevant chemical aspects of these "two faces" of chromium by covering first, the efforts toward a clearer understanding of the carcinogenic properties of chromium compounds. The biomimetic chemistry of Cr(V) complexes illustrates the interactions of the inte
Química Nova. Publicado em: 2002-07
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12. Estudo de reações de 51Cr(VI) com acidos concentrados atraves de metodos cromatograficos
Com o intuito de se verificar a redução ácida de Cr(VI), na ausência de qualquer agente redutor convencional, foram estudados sistemas Cr(VI)-ácido utilizando Cr como marcador. A especiação dos produtos da reação do Cr(VI) com os ácidos concentrados (HCI, HF, HCIO4, CF3SO3H, HNO3 e H2SO4) foi realizada por cromatografia de troca iônica a baixa pre
Publicado em: 1998