کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
67236 48472 2009 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mechanistic aspects of uncatalyzed and ruthenium(III) catalyzed oxidation of dl-ornithine by copper(III) periodate complex in aqueous alkaline medium: A comparative kinetic study
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Mechanistic aspects of uncatalyzed and ruthenium(III) catalyzed oxidation of dl-ornithine by copper(III) periodate complex in aqueous alkaline medium: A comparative kinetic study
چکیده انگلیسی

The oxidation of dl-ornithine monohydrochloride (OMH) by diperiodatocuprate(III) (DPC) has been investigated both in the absence and presence of ruthenium(III) catalyst in aqueous alkaline medium at a constant ionic strength of 0.20 mol dm−3 spectrophotometrically. The stiochiometry was same in both the cases, i.e., [OMH]/[DPC] = 1:4. In both the catalyzed and uncatalyzed reactions, the order of the reaction with respect to [DPC] was unity while the order with respect to [OMH] was < 1 over the concentration range studied. The rate increased with an increase in [OH−] and decreased with an increase in [IO4−] in both cases. The order with respect to [Ru(III)] was unity. The reaction rates revealed that Ru(III) catalyzed reaction was about eight-fold faster than the uncatalyzed reaction. The oxidation products were identified by spectral analysis. Suitable mechanisms were proposed. The reaction constants involved in the different steps of the reaction mechanisms were calculated for both cases. The catalytic constant (KC) was also calculated for catalyzed reaction at different temperatures. The activation parameters with respect to slow step of the mechanism and also the thermodynamic quantities were determined. Kinetic experiments suggest that [Cu(H2IO6)(H2O)2] is the reactive copper(III) species and [Ru(H2O)5OH]2+ is the reactive Ru(III) species.

The oxidation of dl-ornithine (OMH) by diperiodatocuprate(III) (DPC) both in the absence and presence of ruthenium(III) catalyst in alkaline medium at a constant ionic strength was studied spectrophotometrically. The stiochiometry was same in both the cases, i.e., [OMH]/[DPC] = 1:4. Suitable mechanisms were proposed. The active species of DPC and Ru(III) were found to be [Cu(H2IO6)(H2O)2] and [Ru(H2O)5OH]2+ respectively.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Catalysis A: Chemical - Volume 313, Issues 1–2, 2 November 2009, Pages 88–99
نویسندگان
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