Browsing by Autor "Clara Hilda Rios-Reyes"

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A computational study of the chemical reactivity of isoxaflutole herbicide and its active metabolite using global and local descriptors
(Serbian Chemical Society, 2020) Luis Humberto Mendoza-Huízar; Clara Hilda Rios-Reyes; Hector Zuñiga-Trejo
In this work, the chemical reactivity of isoxaflutole (ISOX) and diketonitrile (DKN) was analyzed at the X/6-311++G(2d,2p) (where X = = B3LYP, M06, M06L and ?B97XD) level of theory, in the gas and aqueous phases. The results indicate that DKN, the active metabolite of ISOX, is more stable than isoxaflutole in both phases. ISOX is susceptible to electrophilic and free radical reactions through the isoxazole ring; while the carbonyl group is attacked by nucleophiles. For DKN nucleophilic and free radical attacks are expected on the aromatic ring, while electrophilic attacks are favored on the oxygen atom of the carbonyl groups. The results suggest that the cleavage of the N?O bond in the isoxazole ring is possible through electrophilic and free radical attacks, while electrophilic and free radical attacks will favor substitutions on the carbonyl groups of DKN.
A Kinetic Study of Silver Electrodeposition Onto Pt Ultramicroelectrodes From Amoniacal Solutions
(Croatian Chemical Society, 2020) Jair A. Corona-Castro; Giaan Arturo Álvarez‐Romero; Margarita Rivera; José M. Sausedo-Solorio; Clara Hilda Rios-Reyes; Luis Humberto Mendoza-Huízar
A kinetic study of the Ag electrodeposition onto Pt ultramicroelectrodes of 10, 15 and 25 m of diameter from an aqueous solution containing AgNO3 1 mM + NH4NO3 0.1 M was conducted at overpotential conditions through potentiostatic studies. The analysis of the current density transients indicates the existence of two 2D nucleation and growth processes previous to the 3D nucleation and growth process.
AN ELECTROCHEMICAL STUDY OF THE COBALT ELECTRODEPOSITION ONTO A CARBON FIBER ULTRAMICROELECTRODE
(Sociedad Chilena de Química, 2022) Jair A. Corona-Castro; Giaan Arturo Álvarez‐Romero; Margarita Rivera; Clara Hilda Rios-Reyes; L.E. Bañuelos-García; Eduardo García Sánchez; Luis Humberto Mendoza-Huízar
A kinetic study of the cobalt electrodeposition onto a carbon fiber ultramicroelectrode of 11 m of diameter was conducted in overpotential conditions from an aqueous solution containing 0.01 M CoCl2 + 0.1 M NH4Cl. From the voltamperometric and chronoamperometric studies, it was found that the value of the diffusion coefficient is 1.2x10 -5 cm 2 s -1 . The analysis of the current density transients suggests that cobalt electrodeposition onto a carbon fiber electrode follows an instantaneous nucleation process controlled by spherical diffusion mass transport. Also, the number of active nucleation sites increases as the applied potential decreases.
Influence of Bitartrate Ion Concentration in the Copper Electrodeposition Onto a Polycrystalline Gold Electrode
(Croatian Chemical Society, 2021) M. Hernández; Giaan Arturo Álvarez‐Romero; Margarita Rivera; Simplicio González–Montiel; Clara Hilda Rios-Reyes; Luis Humberto Mendoza-Huízar
In the present work, the influence of the concentration of bitartrate ions (HT) on the copper electrodeposition process was analyzed. The study was carried out from an aqueous solution containing 0.001 M of CuX (where X = (NO3 -)2 ,(Cl -)2, SO4 2-) and x M KHT (where x = 0.005 M, 0.01 M, and 0.015 M). From voltammetric and chronoamperometric studies, the results indicate that copper electrodeposition is a diffusioncontrolled process. The current density transients were well described through a kinetic mechanism involving capacitive and faradaic contributions. The diffusion coefficient values of Cu 1+ and Cu 2+ result to be similar at the different concentration values of potassium bitartrate used in this work.