A DFT study of permanganate oxidation of toluene and its ortho-nitroderivatives

• Published in: Journal of molecular modeling Vol. 20; no. 2; p. 2091
• Main Authors: Adamczyk, Paweł, Wijker, Reto S., Hofstetter, Thomas B., Paneth, Piotr
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2014
• Subjects: Air Pollution; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Hydrogen - chemistry; Kinetics; Manganese Compounds - chemistry; Molecular Medicine; Nitrogen Compounds - chemistry; Nitrogen Compounds - toxicity; Original Paper; Oxidation-Reduction; Oxides - chemistry; Specific Gravity; Theoretical and Computational Chemistry; Thermodynamics; Toluene - chemistry; B3LYP; Permanganate; Nitroaromatic pollutants; HOMA; DFT; Toluene
• ISSN: 1610-2940; 0948-5023
• DOI: 10.1007/s00894-014-2091-1

Calculations of alternative oxidation pathways of toluene and its
ortho
-substituted nitro derivatives by permanganate anion have been performed. The competition between methyl group and ring oxidation has been addressed. Acceptable results have been obtained using IEFPCM/B3LYP/6-31+G(d,p) calculations with zero-point (ZPC) and thermal corrections, as validated by comparison with the experimental data. It has been shown that ring oxidation reactions proceed via relatively early transition states that become quite unsymmetrical for reactions involving
ortho
-nitrosubstituted derivatives. Transition states for the hydrogen atom abstraction reactions, on the other hand, are late. All favored reactions are characterized by the Gibbs free energy of activation, ΔG
≠
, of about 25 kcal mol
−1
. Methyl group oxidations are exothermic by about 20 kcal mol
−1
while ring oxidations are around thermoneutrality.
Figure
Oxidation of toluene and its ortho-nitroderivatives