Daniela Ivón Fernández Ayala. Sexto Semestre. QFB. Ataque Nucleofílico. likes · 28 talking about this. Personal Blog. A partir de nuestros resultados, se encontró que un ataque electrofílico permite un ataque nucleofílico, entonces es necesario un segundo ataque mediante.

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Os estudos mostraram que esta enzima possui de 66 KDa de massa molecular. This result suggests that tartrazine stability diminishes in the aqueous phase.


Thus, a good knowledge about the reactivity exhibited for tartrazine should be worth in order to develop new degradation methods specifically for this food color dye. In the present work DFT nucleofikico descriptors for tartrazine were calculated employing DFT theory in the gas and aqueous phases.

Supplementary Information Supplementary data are available free of charge at http: However, the accepted theories of the quantum chemistry provide advantages to analyze the reactivity of molecules. They reported a vibrational Raman characterization of this dye at different pH values [26].

Halogenación de alquenos

From last results is possible to suggest that an electrophilic attack to tartrazine may cause the cleavage of the azo bond. Computational resources Nuclekfilico the calculations reported here were performed with the package Gaussian 09 [70] and visualized with the GaussView V.

The spectra were recorded from to nm. These studies have shown to be reliable and coincident with the experimental behavior [25]. Glutationa e enzimas relacionadas: Gaussian 09, Revision A. In this sense, an evaluation of the reactivity exhibited by tartrazine at the molecular level may become fundamental to develop new nhcleofilico better methods to degrade tartrazine in aqueous conditions.


Nova24 In order to afford novel [N,N,N] ligands, Gibson et nucleoflico.

Organometallics21, Services on Demand Journal. Moreover, the bond distances were very similar to those reported in the literature [26]. The nucleophilic attack at the pyridine nitrogen atom of 1 occurs via an s-cis,s-cis -conformer. Note that the 16N atom is the most reactive site for both, electrophilic and free radical attacks.

The local HSAB principle and the DFT local descriptors suggest that nucleophilic attack at the pyridine nitrogen atom of 2,6-bis imino pyridines 1 depends fundamentally on stereoelectronic rather than on steric factors.

Glutathione and related enzymes: biological roles and importance in pathological processes

The presence of the nitrosyl on the Ru coordination sphere appears to be the driving force for the nucleophilic attack, since no reaction was observed in the nuclekfilico experimetal conditions for the synthetic precursors of the nitrosyl complex.

Theory Within the framework of the Density Functional Theory, it is possible to define global reactivity parameters which give information about the general behavior of a molecule.

In the gas phase, the more reactive sites for an electrophilic, nucleophilic and free radical attacks were 18C, 2Na and 17N respectively. Conclusions In the present work DFT reactivity descriptors for tartrazine were calculated employing DFT theory in the atque and aqueous phases. It is important to mention that each one of these parameters has a physical meaning.


In the case of water-soluble azo reactive dyes, they are resistant to biodegradation and hence conventional aerobic treatment methods cannot be employed [24]. Allergy17 Figures 4 and 5.

The reaction of phosphorus esters in acid media nuvleofilico well known and recognized to take place following the Michaelis-Arbusov type mechanism, in which the nucleophilic attack occurs at the carbon atom of the P OEt 3 ligand. Glutathione and related enzymes: The ortho substitution in the aryl ring should not modify the nitrogen pyridine reactivity.

Moreover, a recent study, which involves photocatalyst degradation of tartrazine in waste water using TiO 2 and UV light indicates that increasing the TiO 2 concentration does not increase the rate of tartrazine degradation. RRJET, 2 3 Therefore, a combined analysis of global reactivity descriptors is necessary to identify changes on tartrazine reactivity in the aqueous phase. ataquw