Oxidation of Some Water-Soluble Anionic Polyelectrolytes. Oxidation of Carboxymethyl Cellulose Polysaccharide by Hexacholroiridate(IV) in Aqueous Percholorate Solutions. A Kinetic and Mechanistic Appr

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• 作者：Refat Hassan ; Ishaq Zaafarany ; Hideo Takagi
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2013
• 出版时间：January 30, 2013
• 年：2013
• 卷：52
• 期：4
• 页码：1531-1537
• 全文大小：306K
• 年卷期：v.52,no.4(January 30, 2013)
• ISSN：1520-5045

文摘

The kinetics and mechanism of hexacholroiridate(IV) oxidation of carboxymethyl cellulose (CMC) in aqueous solutions at a constant ionic strength of 0.1 mol dm^鈥? has been investigated spectrophotometrically. The experimental results showed first-order dependence in [IrCl₆]^{2鈥?/sup> and fractional first-order kinetics with respect to CMC concentration. An inverse-fractional first-order in [H+] was observed. A kinetic evidence for the formation of 1:1 intermediate complex was revealed. The reaction kinetics seems to be of considerable complexity where one chloride ion from hexacholoiridate(IV) oxidant may act as a bridging ligand between the oxidant and the substrate into the formed intermediate complex. The ionic strength was found to have a negligible influence on the reaction rates. The kinetic parameters have been evaluated, and a tentative reaction mechanism consistent with the kinetic results is discussed.}