14691-59-9Relevant academic research and scientific papers
Proton-Induced Disproportionation of Superoxide Ion in Aprotic Media
Chin, Der-Hang,Chiericato, Glaico,Nanni, Edward J.,Sawyer, Donald T.
, p. 1296 - 1299 (1982)
The proton-induced disproportionation of superoxide ion (O2-) in dimethylformamide and in acetonitrile has been studied by stopped-flow spectrophotometry, cyclic voltammetry, and controlled-potential voltammetry at a rotating-disk electrode.For strongly acidic substrates (HClO4, HCl, and NH4ClO4) the disproportionation reaction is second order with respect to O2-, but too rapid to measure accurately, k > 107 M-1 s-1.With less protic substrates (ascorbic acid, phenols, catechols, alcohols, and water) the rate of disproportionation is first order with respect to O2- and with respect to substrate; proton transfer is the rate-limiting step.In dimethylformamide the second-order rate constants range from k = 2x104 M-1 s-1 for ascorbic acid to k = 1x10-3 for water.On the basis of the kinetic data, a self-consistent mechanism for superoxide disproportionation by acidic substrates in nonaqueous solvents is proposed.
Multireference singles and doubles configuration interaction study of the photoelectron spectrum of HO2-
Vazquez, Gabriel J.,Buenker, Robert J.,Peyerimhoff, Sigrid D.
, p. 7229 - 7238 (2007/10/02)
Multireference singles and doubles configuration interaction (MRD-CI) electronic structure calculations are carried out on the hydroperoxyl radical and its negative ion.Potential energycurves of the ground state, of the anion and of the ground and first excited states of the neutral molecule along the O-OH coordinate are employed to compute the Franck-Condon factors for the electron photodetachment processes HO2(X 2A , A 2A') + e HO2-(X 1A').The theoretical spectrum agrees fairly well the photoelectron spectrum reported by Oakes, Harding, and Ellison, and is consistent with their assignment of the peaks K and D as origins for the electron loss transitions to the HO2 A and X states, respectively.An alternative choice of peak E as XX- origin yields better agreement between computed and experimental Franck-Condon factors than does the peak D assignment, but is less satisfactory when energetic considerations are taken into account.Two independent ab initio results lend support to the value of 1.078+/-0.017 eV for the measured adiabatic electron affinity of HO2, which is in good agreement with the best value inferred from the MRD-CI calculations of 1.069+/-0.05 eV.The matter is not settled, however, as some inconsistencies in the experimental data still cast some doubts on the assignment of the peaks and the accuracy of the HO2 EA.
