Complex Anions
Mostrando 13-24 de 54 artigos, teses e dissertações.
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13. Estudo de um sensor cromogênico aniônico fundamentado na competição entre uma merocianina e um ânion pelo calix[4]pirrol
This work has studied the assembly of a chromogenic sensor that uses as receptor calyx[4]pyrrole (CP), which is capable to recognize fluoride with high efficience, and two solvatochromic dyes, Brookers merocyanine (MB) and Reichardts dye (CR), as signalizing unity. The solutions of MB in acetonitrile, a low polarity medium, exhibit violet color. It was obser
Publicado em: 2007
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14. Use of modified silica gel for concentrating Pb (II) and Cd (II) occurring in form of complex anions
The performance of silica gel, modified by the impregnation with a high molecular weight quaternary amine (triethyl octadecyl ammonium iodide), used for the concentration of heavy metals occurring in water is studied. The material under study captures Cd, Pb, which are capable of forming stable complexes with I- ions.The results obtained about the metal capt
Eclética Química. Publicado em: 2007
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15. Center metallic effect on intermolecular interactions of complexes [M(CN)5NO]x- with poly(ethylene oxide) in aqueous two-phase systems / Efeito do centro metálico nas interações intermoleculares dos complexos [M(CN)5NO]x- com o poli(óxido de etileno) em sistemas aquosos bifásicos
In this thesis has been studied the metallic center influences of pentacianonitrosylmetalates, [M(CN)5NO]x-, on the partition coefficient (K), of these complex anions in aqueous two-phase systems (ATPS). The ATPS were obtained by mixing stock aqueous solutions of an inorganic salt (Li2SO4 or Na2SO4) with a stock solution of poly(ethylene oxide) of average mo
Publicado em: 2007
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16. Photoluminescent Behaviour of tetrakis(b-diketonates) Complex Anions with Rare Earth Ions - Eu3+, Gd3+, Tb3+ e Tm3+ / Comportamento fotoluminescente dos ânions complexos tetrakis(-dicetonatos) de Íons terras raras - Eu3+ , Gd3+ , Tb3+ e Tm3+
Neste trabalho, os complexos tetrakis(ß-dicetonato) de terras-raras, (Q)[TR(β-dicetonato)4 ] {(Q = Li+ , Na+ , K+ , (Et3 NH)+ , (Morf)+ , (TMPip)+ e (Diciclo)+ ); (TR3+ = Eu3+ , Gd3+ , Tb+ e Tm3+ ) e (β-dicetonato = acac, dbm e tta), foram sintetizados, caracterizados e suas propriedades ópticas investigadas por meio de espectroscopia luminescent
Publicado em: 2007
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17. Synthesis and crystal structures of new complex salts containing both cationic and anionic tellurium(IV) species: the role of secondary bonds in the arrangement of tellurium based tectons
Neste trabalho divulgamos a síntese e a estrutura cristalina de uma série de três novos complexos de telúrio(IV), [Te(C6H5)(CH3)2]][TeX 4(C6H5 )], X = Cl (1), Br (2) ou I (3). Nesses complexos, as ligações secundárias promovem diferentes arranjos estruturais, mostrando o caráter tectônico das espécies de telúrio. Em 1 e 2, a interação Te···X
Journal of the Brazilian Chemical Society. Publicado em: 2006-12
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18. "Estudo do processo de complexação de calixarenos com íons metálicos e espécies neutras por simulações de dinâmica molecular" / A study of the complexation process of calixarenes with metallic ions and neutral species from molecular dynamic simulations
We report a series of Molecular Dynamics simulations, in vacuum and in acetonitrile solution, on the complexation process of the calixarens tetraethylester p-tert-butyl calix[4]arene (CLE) and tetramethylketone p-tert-butyl calix[4]arene (CLC) with Pb2+ and Cd2+ anions and neutral species. The solvent and calixarene molecules were modeled based on the OPLS-A
Publicado em: 2006
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19. 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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20. Caracterização magnética, térmica e espectral de 2,6-dimetóxibenzoatos de Co(II), Ni(II) e Cu(II)
Os anions complexos do ácido 2,6-dimetóxibenzóico com ions de Co(II), Ni(II) e Cu(II) foram sintetizados como sólidos policristalinos e caracterizados por análise elementar, espectroscopia, estudos magnéticos e também por medidas de difratometria de raios X e termogravimetria. Os complexos analisados apresentaram a seguinte coloração: rosa para os c
Eclética Química. Publicado em: 2006
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21. Iodide-selective membrane electrode based on salophen complex of cobalt (III)
Neste trabalho foi preparado um eletrodo altamente seletivo de membrana de PVC com o complexo cobalto-salofen. O sensor mostra uma seqüência seletiva anti-Hofmeister, com preferência por íons iodeto sobre vários anions comuns. O eletrodo apresentou uma dinâmica linear na faixa de 5,0×10-7 a 1,0×10-1 mol L-1, com uma inclinação Nernstiana de -58,9 m
Journal of the Brazilian Chemical Society. Publicado em: 2005-06
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22. Geoquímica das Águas e dos Sedimentos da Bacia do Rio Gualaxo do Norte, Leste-Sudeste do Quadrilátero Ferrífero (MG): Estudo de uma Área Afetada por Atividades de Extração Mineral
The aim of the present geochemical study was to understand the physical-chemical behavior of water and sediments affected by anthropogenic interferences during almost three centuries of mining. Several analytical techniques were used which, together with geological and socio-economic information of the area, permitted to obtain a picture of the environmental
Publicado em: 2001
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23. Participação do oxido nitrico no desenvolvimento da encefalomielite alergica experimental em ratos
Nitric oxide (NO) is a free radical endogenously synthetised by oxidation of one of the guanidinum nitrogen atoms of the aminoacid L-arginine by molecular oxygen. This biosynthesis is catalised by a family of enzimes generically known as nitric oxide synthases (NOS), which can be inhibited by structural analogs of L-arginine having substituent groups at the
Publicado em: 2001
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24. Estudo potenciométrico dos equilíbrios no sistema manganês (II) / azoteto / The potentiometric study of complex formation in the manganese (II)/azide system
The equilibria of complex formation between manganese(II) cations and azide anions were studied in aqueous medium by an indirect potentiometric method, at 25°C and ionic strengh 2.0 M (NaClO4). The equilibrium data were based on pH measurements of Mn(II) in N3¯/HN3 buffers. Metal ion concentration changing from 20 to 100 mM have defined one single form
Publicado em: 1993