http://nopr.niscair.res.in/handle/123456789/2072 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/2197 Title: Kinetics and mechanism of oxidation of aliphatic alcohols by [bis(trifluoroacetoxy)iodo]benzene <br/> <br/>Authors: Banerjia, Jayshree; Sharmaa, Pradeep K; Banerjib, Kalyan K <br/> <br/>Abstract: The oxidation of some aliphatic alcohols by [bis(trifluoro-acetoxy)iodo]benzene (TFAIB) in aqueous acetic acid solution leads to the formation of the corresponding carbonyl compounds. The reaction is first order in TFAIB and a Michaelis-Menten kinetics is obtained with respect to the alcohols. The reaction shows a first order dependence on hydrogen ions. The oxidation of [1,1–²H₂]ethanol and [2-²H]propan-2-ol exhibits the presence of a substantial primary kinetic isotope effect at 298 K (kH/kD = 3.64 and 3.89 respectively). The rate of disproportionation of the intermediate is susceptible to both polar and steric effects of the substituents. A suitable mechanism has also been proposed. <br/> <br/>Page(s): 1213-1217 Tue, 29 Jul 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/2137 Title: Micellar properties of benzyldimethyldodecylammonium bromide in aquo-organic solvent media <br/> <br/>Authors: Ghosh, Kallol K; Baghel, Vidyacharan <br/> <br/>Abstract: The micellar properties of benzyldimethyldodecyl-ammonium bromide has been studied by conductivity method in the binary mixtures (10% v/v) of acetonitrile, dimethyl sulfoxide, tetrahydrofuran,1,4-dioxane, methanol and ethylene glycol at different temperatures ranging from 300 to 319 K. The thermodynamics of micellization i.e, Gibbs free energy (ΔGºm), enthalpy (ΔHºm), and entropy (ΔSºm) have also been determined. The increase of critical micelle concentration with solvent mixtures has been discussed on the basis of water structure, solvent properties and hydrophobic interaction. <br/> <br/>Page(s): 1230-1233 Tue, 29 Jul 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/2136 Title: Kinetics of oxidation of gabapentin (neurontin) by chloramine-T in perchloric acid medium <br/> <br/>Authors: Mohan, K; Jagadeesh, M B <br/> <br/>Abstract: A kinetic study of oxidation of gabapentin (neurontin) by chloramine-T has been carried out in HClO₄ medium at 303 K. The reaction rate is first order dependence on [CAT]o, fractional order on [GP]o and an inverse fractional order on [H+]. Effects of added p-toluenesulfonamide and halide ions, and varying ionic strength of the medium have been investigated and the activation parameters evaluated. The reaction fails to initiate polymerization of acrylonitrile. The reaction stoichiometry and oxidation products have been identified and a suitable mechanism has been proposed. <br/> <br/>Page(s): 1226-1229 Tue, 29 Jul 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/2135 Title: Kinetics and mechanism of Mn(II) catalyzed oxidation of acridine yellow by chloramine-T <br/> <br/>Authors: Pare, Brijesh; Ayachit, Manisha; Jonnalagadda, S B <br/> <br/>Abstract: The kinetics and mechanism of the uncatalyzed and Mn(II) catalyzed oxidation of acridine yellow(3,6-diamino-2,7-dimethyl acridine hydrochloride) dye by chloramine-T in acidic media has been studied using spectrophotometry. With excess concentrations of other reactants, the reaction rate follows pseudo first order kinetics with respect to acridine yellow. The uncatalyzed reaction has fractional order dependence on chloramine-T as well as on H+ concentration. The catalyzed reaction follows first order kinetics in catalyst [Mn(II)]. Variations of ionic strength has no influence on the reaction rate suggesting that neutral charged species are involved in the rate determining step. Increase in the addition of p-toluenesulfonamide results in decrease in rate constant values. The basic stoichiometric equation is as follows: AY⁺ + ArSO₂NHCl + H₂O = P⁺ + ArSO₂NH₂ +CH₃CH₂OH + CH₃CN + 2HCl, where P⁺ = 7-aminoquinoline-2, 3-dicarboxylic acid. The lowest catalytic limit for Mn(II) has been found to be 1.0x10⁻⁸ mol dm⁻³. On the basis of various kinetic investigations and product analysis mechanisms have been proposed. <br/> <br/>Page(s): 1222-1225 Tue, 29 Jul 2008 22:58:59 GMT