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Singh M.,Kalyan Post Graduate College
Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry | Year: 2012

The oxidation of D-sucrose by N-bromosuccinimide and surfactants as a catalyst in the presence of acidic medium was studied at 45°C (± 0.1°C). The rate studies were made under pseudo-first-order conditions with an excess of sugar over the oxidant. In this aim was followed a mechanistic and structural investigation based on a micellar kinetic study. The kinetics revealed first-order dependence on N-bromosuccinimide and fractional-order dependence on D-sucrose. Variations of mercuric acetate had an insignificant effect on reaction rate. The solvent effect revealed that negative dielectric effect. The influence of salts on the reaction rate was also studied. Succinimide and sulfuric acid inhibit the rate. The rate constant (k W), binding constants (K S+K O), and corresponding activation parameters (E a, ΔH #, ΔS #, and ΔG #) were determined. A detailed mechanism with associated reaction kinetics is presented and discussed. Differences among the oxidation rates of the D-sucrose in the presence of various surfactants discussed qualitatively in terms of Berezin's model, nature of surfactants, and charge of surfactants. © 2012 Copyright Taylor and Francis Group, LLC.


Goswami G.K.,Kalyan Post Graduate College | Yadav A.K.,Galgotias University | Mishra M.,Shri Shankaracharya Engineering College
International Journal of Theoretical Physics | Year: 2014

In the present work, we have searched the existence of ΛCDM-type cosmological model in anisotropic Heckmann-Schucking space-time. The matter source that is responsible for the present acceleration of the universe consist of cosmic fluid with p = ωiρ, where ωi is the equation of state parameter for different cosmic fluids. The Einstein’s field equations have been solved explicitly under some specific choice of parameters that isotropizes the model under consideration. It has been found that the derived model is in good agreement with recent SN Ia observations. Some physical aspects of the model has been discussed in detail. © 2014, Springer Science+Business Media New York.


Singh M.,Kalyan Post Graduate College
Research on Chemical Intermediates | Year: 2013

Kinetic investigations of oxidation of dextrose by N-bromophthalimide (NBP) in acidic medium in the presence of mercuric(II) acetate as a scavenger have been studied. In both the absence and presence of surfactants, the oxidation kinetics of dextrose by NBP shows a first-order dependence on NBP, fractional order on dextrose, and negative fractional order dependence on sulfuric acid. The determined stoichiometric ratio was 1:1 (dextrose:NBP). The variation of Hg(OAC)2 and phthalimide (reaction product) have an insignificant effect on reaction rate. Effects of surfactants, added acrylonitrile, added salts, and solvent composition variation have been studied. Activation parameters for the reaction have been evaluated from Arrhenius plot by studying the reaction at different temperature. The rate law has been derived on the basis of obtained data. A plausible mechanism has been proposed from the results of kinetic studies, reaction stoichiometry and product analysis. The role of anionic and non-ionic micelle was best explained by the Berezin's model. © 2012 Springer Science+Business Media B.V.


Katre Y.,Kalyan Post Graduate College | Nayak S.,Kalyan Post Graduate College | Sharma D.N.,Kalyan Post Graduate College | Singh A.K.,Vishwanath Yadav Tamaskar Post Graduate Autonomous College
Research on Chemical Intermediates | Year: 2012

The kinetics of micellar catalyzed oxidation of galactose by N-bromophthalimide was studied in the presence of acidic medium at 308 K. The oxidation reaction exhibits first-order kinetics with respect to oxidant (N-bromophthalimide), fractional order with respect to substrate (galactose) and positive fractional order with respect to HClO 4 on the rate of reaction. The rate of the reaction increased with decreasing the dielectric constant of the medium. With a progressive increase in the concentration of CTAB, the rate of reaction increased and after reaching peak kobs, decreased at higher concentrations of CTAB. There catalytic roles are best explained by Berezin's model. The influence of salts on the reaction rate was also studied. The various activation parameters have been calculated. The rate constant and binding constant with the surfactant have also been evaluated. A suitable mechanism consistent with the experimental findings has been proposed. © Springer Science+Business Media B.V. 2011.


Katre Y.,Kalyan Post Graduate College | Singh M.,Kalyan Post Graduate College | Singh A.K.,Vishwanath Yadav Tamaskar Post Graduate Autonomous College
Journal of Dispersion Science and Technology | Year: 2011

The kinetics and mechanism of N-bromosuccinimide (NBS) oxidation of D-mannose in the absence and presence of cetyltrimethy lammonium bromide (CTAB) in acidic media have been studied under the condition [D-mannose]T >> [NBS]T at 40°C. Under the kinetic conditions, both the slower uncatalyzed and faster catalyzed paths go on. Both the paths show the fractional and first order dependence on [D-mannose] and [NBS]T, respectively. The rate decreased with increase in acidity. Neither succinimide (NHS) nor Hg(II) influenced the reaction rate. Activation parameters of the reactions were determined by studying the reaction at different temperatures (30-50°C). The influence of salts on the reaction rate was also studied. CTAB accelerates the reactions and the observed effects have been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. In the reaction, approximately 1 mole of NBS oxidized one mole of D-mannose. A reaction scheme of the oxidation of D-mannose by NBS was found to be in consistent with the rate law and the reaction stoichiometry. © Taylor & Francis Group, LLC.

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