Competition between electron transfer and base-induced elimination mechanisms in the gas-phase reactions of superoxide with alkyl hydroperoxides
| Autor: | Ezequiel F. V. Leitão, Miguel A. F. de Souza, Silmar A. do Monte, Elizete Ventura |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Base (chemistry) Superoxide General Physics and Astronomy Alcohol 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Medicinal chemistry Decomposition 0104 chemical sciences chemistry.chemical_compound Electron transfer chemistry Ozonide Molecule Physical and Theoretical Chemistry 0210 nano-technology Alkyl |
| Zdroj: | Physical Chemistry Chemical Physics. 23:5583-5595 |
| ISSN: | 1463-9084 1463-9076 |
| Popis: | Understanding the mechanism responsible for peroxides decomposition is essential to explain several biochemical processes. The mechanisms of the intrinsic reactions between the superoxide radical anion (O2˙-) and methyl, ethyl, and tert-butyl hydroperoxides (ROOH, with R = Me, Et, and t-Bu) have been characterized to understand the mechanism responsible for peroxides decomposition. The reaction energy diagrams suggest a competition between the spin-allowed and spin-forbidden electron transfer (ET), and base-induced elimination (ECO2) mechanisms. In all cases, the spin-allowed ET mechanism describes formation of the ozonide anion radical (O3˙-), either complexed with an alcohol molecule or separated. For the O2˙-/MeOOH(EtOOH) reactions, HCO2- (MeCO2-) + H2O + HO˙ and OH- + CH2O(MeCHO) + HO2˙ products are associated with the spin-forbidden ET and ECO2 channels, respectively. On the other hand, for the reaction between O2˙- and t-BuOOH, the spin-forbidden ET route describes formation of the MeCOCH2- enolate (either separated or hydrated) along with the methyl peroxyl (MeO2˙) radical. In addition, the regeneration of O2˙-via spin-forbidden ET and ECO2 channels was also characterized from the decomposition of ROOH, yielding diols (CH2(OH)2 and MeCH(OH)2), aldehydes (CH2O and MeCHO), and oxirane (cyc-CH2CMe2O). |
| Databáze: | OpenAIRE |
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