Reações com transferencia de eletrons : sintese, caracterização e eletroquimica de complexos de niquel (II) e ferro II) piridilimino-oxima

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciencias Fisicas e MatematicasOs ligantes foram sintetizados em meio de eter diisopropílico e caracterizados com dados da literatura. Os complexos de níquel foram isolados a partir de uma mistura de 1:2 de sal de nitrato de níquel hexaaquo e de ligante, respectivamentee em meio alcoólico. Os complexos de ferro foram preparados analogamente, porém em meio aquoso. Ambos foram caracterizados através de análise elementar, espectroscopia vibracional de infravermelho espectroscopia eletrônica de ultravioleta e visível. A determinação das constantes de protonação para ambos os complexos foi feita através de titulação potenciométrica e comprovados eletroquimicamente através da técnica de voltametria cíclica

Reatividade, espectroscopia e eletroquimica de complexos macrociclicos de 'Fe POT II' 'Fe POT III', um modelo bioinorganico

Tese (doutorado) - Universidade Federal de Santa Catarina. Centro de Ciencias Fisicas e MatematicasÉ de substancial interesse a caracterização de complexos de ferro que se assemelham a centros ativos de biomoléculas, principalmente quando estes modelos possuem a capacidade de captar e reduzir moléculas de oxigênio. O complexo [(Fe(II) (TIM)(H2O2]-2, onde TIM é o ligante 2,3,9,10-tetrametil-1,4,8,11-tetraazaciclotetradeca-1,3,8,10-tetraeno N4, forma um complexo dímero na proporção de 2 moles de complexo para cada mol de O2, tornando-se o núcleo metálico formalmente oxidado

Electrochemical and spectroscopic studies of the complexed species of models of nitrohumic acids derived from phthalic acid

The study of model compounds is necessary in order to obtain information about complex organic substances as in the case of humic substances (HS). These substances are potential organic fertilizers and have other important functions in soils, natural waters and organic sediments. The main chemical properties of the complexes formed from 3-nitrophthalic and 4-nitrophthalic acids and the metal ions Fe(III) and Zn(II) were studied using potentiometric titrations, ultraviolet-visible spectroscopy (UV-Vis) and cyclic voltammetry (CV). A trial potentiometric titration was done with a mixture of the models for nitrohumic acids and Cu(II). Equilibrium constants for the systems were calculated and UV-Vis and CV were employed to monitor the formation of the species. Comparative studies involving chelating centres of nitrosalicylic acids and nitrocatechols with Fe(III), Zn(II) and Cu(II) are presented. The initial studies involving the nitrohumic substances (NHS), a laboratory artifact of HS have been made and good evidence was found for the further use of NHS as a potential organic fertilizer as well as HS. In this present work one of the observed advantages of NHS over HS was that some aromatic nitro- centres can bind some metal ions at p[H] values of normal soils, near 7.0 to 7.5

Synthesis and X-ray crystal structure of the [Ni(HDPE)2][NO3]2.2H2O.

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