Quantum-Chemical Study of the Mechanism of Hydrocarbon Oxidation with Molecular Oxygen

The minimal kinetic scheme of the mechanism of hydrocarbon oxidation with molecular oxygen was studied by the PM3 semiempirical quantum-chemical method and also by the B3LYP hybrid density functional method using the 3-21G and 6-21G(d) basis sets and the GAUSSIAN 94 software. The energy characteristics and structural parameters of the reactants, products, and transition states of some elementary stages were determined. The simplest hydrocarbons, methane and ethane, were taken as substrates. For same reactions the effect of substituents, including bulky groups (methylbenzene, ethylbenzene, isopropylbenzene), was considered.