12292-23-8Relevant articles and documents
Effect of chloride ion on the kinetics and mechanism of the reaction between chlorite ion and hypochlorous acid
Kormanyos, Balazs,Nagypal, Istvan,Peintler, Gabor,Horvath, Attila K.
, p. 7914 - 7920 (2009/02/08)
The effect of chloride ion on the chlorine dioxide formation in the ClO2--HOCl reaction was studied by following ?ClO2 concentration spectrophotometrically at pH 5-6 in 0.5 M sodium acetate. On the basis of the earlier experimental data collected without initially added chloride and on new experiments, the earlier kinetic model was modified and extended to interpret the two series of experiments together. It was found that the chloride ion significantly increases the initial rate of ?ClO2 formation. At the same time, the ?ClO2 yield is increased in HOCl but decreased in ClO2- excess by the increase of the chloride ion concentration. The two-step hydrolysis of dissolved chlorine through Cl2 + H2O ? Cl 2OH- + H+ and Cl2OH- ? HOCl + Cl- and the increased reactivity of Cl 2OH- compared to HOCl are proposed to explain these phenomena. It is reinforced that the hydrolysis of the transient Cl 2O2 takes place through a HOCl-catalyzed step instead of the spontaneous hydrolysis. A seven-step kinetic model with six rate parameters (constants and/or ratio of constants) is proposed on the basis of the rigorous least-squares fitting of the parameters simultaneously to 129 absorbance versus time curves measured up to ～90% conversion. The advantage of this method of evaluation is briefly outlined.
Production of Cl2O2 from the Self-Reaction of the ClO Radical
Molina, L. T.,Molina, M. J.
, p. 433 - 437 (2007/10/02)
The species Cl2O2 has been generated in gaseous flow system at 220-240 K by reacting Cl atoms with one of three different ClO precursors: O3, Cl2O, or OClO.The infrared spectra of the reactive mixture indicate that the least two different dimers are produced: a predominant form with bands centered at 1225 and 1057 cm-1 attributed to ClOOCl, and a second form with a band at 650 cm-1 attributed to ClOClO.The UV spectrum of the predominant form shows a maximum adsorption cross section of ca.6.5 x 1E-18 cm-1/molecule around 720 nm, with a wing extending beyond 300 nm.The implications of these results for the chemistry of the stratosphere are discussed.
