http://nopr.niscair.res.in/handle/123456789/12171 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/12178 Title: Mechanistic investigations on manganese(II) catalyzed oxidation of substituted 4-oxo-4-arylbutanoic acids by bromate in acid medium <br/> <br/>Authors: Reddy, Cherkupally Sanjeeva; Manjari, Padma Sunitha <br/> <br/>Abstract: The manganese(II)-catalyzed oxidation of substituted 4-oxo-4-arylbutanoic acids (4-oxo acids) by bromate, in aqueous acetic acid medium containing sulphuric acid, has been studied. The reaction is first order each in [bromate] and [acid], less than unity order in both [substrate] and [catalyst], and also shows solvent isotope effect of 0.60 (<i style="">k</i>_c′ (H₂O)/<i style="">k</i>_c′ (D₂O)). Oxidation rate is not much affected by electron withdrawing substituents, although it is susceptible to electron demand at the seat of the reaction. The linear free-energy relationship is characterized by smooth curves in Hammett plots of log <i style="">k</i> versus σ. However, the plots are linear with excellent correlation coefficient at all the studied temperatures when Brown’s σ<b style="">⁺</b> values are used. The reaction constant is negative and increases with decrease in temperature. The mechanism involving decomposition of the complex, formed by participation of the neighboring group of 4-oxo acid and intramolecular catalysis of Mn(II) is proposed, wherein, both the C–C bond-breaking and C–O bond-making in the oxidation are involved. However, these two processes are influenced in different ways by the electron withdrawing and electron releasing substituents. A π-complex formation between Mn(II) and -ene of the enol form of oxo acid is proposed. <br/> <br/>Page(s): 979-990 http://nopr.niscair.res.in/handle/123456789/12177 Title: Performance of phosphoric acid doped polyaniline as electrode material for aqueous redox supercapacitor <br/> <br/>Authors: Radhakrishnan, S; Muthukannan, R; Kamatchi, U; Rao, Chepuri R K; Vijayan, M <br/> <br/>Abstract: Phosphoric acid doped polyaniline has been synthesized chemically and electrochemically and tested for its specific capacitance properties by constructing a supercapacitor using stainless steel electrodes. Both the samples are characterized by UV-vis, FTIR, XRD and electrochemical methods. The electrochemically grown samples exhibit higher capacitance values in the range of 244-305 F/g. This is due to the higher purity of the electrochemically prepared polymer due to repeated cycling of the potential. Chemically prepared samples show lower capacitance values due to over-oxidation of the polymer and presence of impurities. <br/> <br/>Page(s): 970-978 http://nopr.niscair.res.in/handle/123456789/12176 Title: L-cysteine-nano-gold modified glassy carbon electrode and its application for determination of dopamine hydrochloride <br/> <br/>Authors: Song, Yang; Song, Yuan-Zhi; Zhu, An-Feng; Zhong, Hui <br/> <br/>Abstract: A sensor based on l-cysteine-gold-nanoparticle modified glassy carbon electrode has been prepared. Electrochemical behaviour of dopamine hydrochloride at l-cysteine-gold-nanoparticle modified glassy carbon electrode is investigated. A simple, sensitive, and inexpensive method for determination of dopamine hydrochloride is proposed. <br/> <br/>Page(s): 1006-1009 http://nopr.niscair.res.in/handle/123456789/12175 Title: Oxidation of alcohols with hydrogen peroxide catalyzed by supported Fe(III) porphyrins <br/> <br/>Authors: Masoudian, Shahla; Yahyaei, Hooriye <br/> <br/>Abstract: Mild and efficient oxidation of alcohols with hydrogen peroxide catalyzed by iron(III) tetrakis(<i>p</i>-sulfonatophenylporphyrinato)acetate, supported on polyvinylpyridine and Amberlite IRA-400 at room temperature is reported. The catalysts used in this study show high activity, not only in the oxidation of benzyl and linear alcohols but also in the oxidation of secondary alcohols at room temperature. The catalysts can be reused several times without significant loss of their activity. <br/> <br/>Page(s): 1002-1005