14998-27-7Relevant articles and documents
Electron Affinity of Chlorine Dioxide
Babcock, L. M.,Pentecost, T.,Koppenol, W. H.
, p. 8126 - 8127 (1989)
The flowing afterglow technique was used to determine the electron affinity of chlorine dioxide.A value of 2.37+/-0.10 eV was found bracketing between the electron affinities of HS and SF4 as a lower limit and that of NO2 as an upper limit.This value is in excellent agreement with 2.32 eV predicted from a simple thermodynamic cycle involving the reduction potential of the ClO2/ClO2- couple and a Gibbs hydration energy identical with that of SO2-.
Chlorine dioxide reduction by aqueous iron(II) through outer-sphere and inner-sphere electron-transfer pathways
Wang, Lu,Odeh, Ihab N.,Margerum, Dale W.
, p. 7545 - 7551 (2004)
The reduction of ClO2 to ClO2- by aqueous iron(II) in 0.5 M HClO4 proceeds by both outer-sphere (86%) and inner-sphere (14%) electron-transfer pathways. The second-order rate constant for the outer-sphere reacti
Nucleophile Assistance of Electron-Transfer Reactions between Nitrogen Dioxide and Chlorine Dioxide Concurrent with the Nitrogen Dioxide Disproportionation
Becker, Robert H.,Nicoson, Jeffrey S.,Margerum, Dale W.
, p. 7938 - 7944 (2008/10/09)
The reaction of chlorine dioxide with excess NO2- to form ClO2- and NO3- in the presence of a large concentration of ClO2- is followed via stopped-flow spectroscopy. Concentrations are set to establish a preequilibrium among ClO2, NO2-, ClO2-, and an intermediate, NO2. Studies are conducted at pH 12.0 to avoid complications due to the ClO2-/NO2- reaction. These conditions enable the kinetic study of the ClO2 reaction with nitrogen dioxide as well as the NO2 disproportionation reaction. The rate of the NO2/ClO2 electron-transfer reaction is accelerated by different nucleophiles (NO2- > Br- > OH- > CO32- > PO43- > ClO2- > H 2O). The third-order rate constants for the nucleophile-assisted reactions between NO2 and ClO2 (kNu, M -2 s-1) at 25.0 °C vary from 4.4 × 10 6 for NO2- to 2.0 × 103 when H2O is the nucleophile. The nucleophile is found to associate with NO2 and not with ClO2 in the rate-determining step to give NuNO2+ + ClO2-. The concurrent NO2 disproportionation reaction exhibits no nucleophilic effect and has a rate constant of 4.8 × 107 M-1 s -1. The ClO2/NO2/nucleophile reaction is another example of a system that exhibits general nucleophilic acceleration of electron transfer. This system also represents an alternative way to study the rate of NO2 disproportionation.
Bromite ion catalysis of the disproportionation of chlorine dioxide with nucleophile assistance of electron-transfer reactions between ClO2 and BrO2 in basic solution
Wang, Lu,Nicoson, Jeffrey S.,Huff Hartz, Kara E.,Francisco, Joseph S.,Margerum, Dale W.
, p. 108 - 113 (2008/10/08)
The rate of ClO2 conversion to ClO2- and ClO3- is accelerated by BrO2-, repressed by ClO2-, and greatly assisted by many nucleophiles (Br- > PO43- > HPO42- > CO32- > Cl- ~ OH- > CH3COO- ~ SO42- C5H5N ? H2O). The kinetics (at p[H+] = 9.3-12.9) show that the first step of the mechanism is an electron transfer between ClO2 and BrO2- (k1 = 36 M-1 s-1) to give ClO2- and BrO2. This highly reversible reaction (k1/k-1 = 1 × 10-6) accounts for the observed inhibition by ClO2-. The second step is an electron transfer between ClO2 and BrO2 to regenerate BrO2- and form ClO3-. A novel aspect of the second step is the large kinetic contribution from nucleophiles (kNu) that assist the electron transfer between ClO2 and BrO2. The kNu (M-2 s-1) values at 25.0 °C vary from 2.89 × 108 for Br- to 2.0 × 104 for H2O.