http://nopr.niscair.res.in/handle/123456789/2071 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/2196 Title: Synthesis, crystal structure, electronic spectra and density functional studies on 1N-phenyl-3-(3,4-dichlorophenyl)-5-phenyl-2-pyrazoline <br/> <br/>Authors: Zhaoa, Pu Su; Wanga, Hong Yan; Lia, Rong Qing; Guo, Huan Mei <br/> <br/>Abstract: 1N-Phenyl-3-(3,4-dichlorophenyl)-5-phenyl-2-pyrazoline has been synthesized and characterized by elemental analysis, IR, UV-vis and X-ray single crystal diffraction studies. Density functional calculations have been carried out for the compound by using B3LYP method at 6-311G** basis set. The calculated results show that the predicted geometry resembles the structural parameters. The electronic absorption spectra calculated in gas phase are better than those calculated in EtOH solvent to model the experimental electronic spectra and the Natural Bond Orbital (NBO) analyses suggest that the above electronic transitions are mainly assigned to π → π* transitions. On the basis of vibrational analyses, the thermodynamic properties of the compound at different temperature have been calculated, revealing the correlations between C⁰p, m, S⁰m and temperature. <br/> <br/>Page(s): 986-991 Sat, 28 Jun 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/2125 Title: Extraction chromatographic separation of Ga(III) with the high molecular mass liquid cation exchanger SRS-100 <br/> <br/>Authors: Mandal, Bhabatosh; Ghosh, Niladri <br/> <br/>Abstract: A selective method has been developed for the extraction chromatographic separation of Ga(III) with SRS-100 (liquid cation exchanger) coated on silanised silica gel. Its quantitative extraction has been achieved in 2.5 h from 0.1 M acetate buffer (pH 5.5-6.5). The effects of pH, flow-rate and stripping agents on extraction and elution have been investigated. Exchange capacity of the prepared exchanger at different temperatures with respect to Ga(III) has been determined. Breakthrough capacity and preconcentration factor at different pH values have been investigated. The effect of pH on Rf in ion exchange paper chromatography has also been investigated. Ga(III) has been separated from its synthetic binary and multi-component mixtures containing various metal ions as are found in ores and alloy samples. The method effectively permits sequential separation of Ga(III) from synthetic quaternary mixtures containing its congeners Al(III), In(III) and Tl(III). A plausible mechanism for the extraction of Ga(III) is also suggested. <br/> <br/>Page(s): 1041-1046 Sat, 28 Jun 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/2124 Title: Kinetics of oxidation of non-ionic surfactants (Triton X-100 and Brij-35) by KMnO₄ in H₂SO₄ medium <br/> <br/>Authors: Shukla, Pragya; Upadhyay, Santosh K <br/> <br/>Abstract: The kinetics of oxidation of non-ionic surfactants, viz. polyoxyethylene(10)octylphenol (Triton X-100) and polyoxyethyleneglycol dodecylether (Brij-35) by potassium permangnate in aqueous H₂SO₄ medium have been investigated in temperature range 35-45C. The reactions show first order dependence of rate with respect to [MnO₄⁻]. The order of reaction in surfactant and H₂SO₄ decreases from unity at higher [surfactant] and [H₂SO₄], respectively. Probable reaction mechanism involving an intermediate between surfactant and active species of the oxidant is proposed and constants involved in the rate law have been evaluated. <br/> <br/>Page(s): 1037-1040 Sat, 28 Jun 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/2123 Title: Brij-35 micellar catalysed chloramine-T oxidation of vitamins: A kinetic study <br/> <br/>Authors: Shukla, Varuna; Upadhyay, Santosh K <br/> <br/>Abstract: The kinetics of oxidation of the vitamins (B₁ and B₆) by sodium salt of p-toluene sulfonamide (Chloramine-T) have been studied in presence of a non-ionic surfactant, i.e., polyoxyethylene(23)laurylether (Brij-35) in perchloric acid medium. Catalytic effect of Brij-35 micelle has been observed on the rate of oxidation. The reactions show first order, fractional order and zero-order dependence of rate with respect to chloramine-T, vitamins and HClO₄, respectively. The mechanism in absence as well as in presence of surfactant has been proposed. The spectrophotometric evidence supports the binding/association between chloramine-T and Brij-35 micelle. The kinetic data have also been rationalised in terms of Menger and Portnoy’s kinetic model and binding parameters have been evaluated. <br/> <br/>Page(s): 1032-1036 Sat, 28 Jun 2008 22:58:59 GMT