Reaction of Ethylene with Methoxyl Radicals: A Quantum-Chemical Study
摘要
The addition of methoxyl radical СН3О• to ethylene with the formation of various isomers and oxygen-coordinated forms of the СН3ОСН2СН2• radical was analyzed in detail. The scheme of possible reactions involving these species was analyzed. This radical and products of its further transformations can play a certain role in the mechanism of the gas-phase oxidation of hydrocarbons. The potential energy surface of the СН3О• + С2Н4 system was analyzed within the framework of B3LYP and M06-2X hybrid methods of the density functional theory (DFT) and of CBS-QB3 ab initio composite method of quantum-chemical calculations. The minimal energy pathways of the reactions CH2O + C2H5•, CH3OH + C2H3• and of the CH3OCH2CH2• adduct formation were calculated. In particular, the reactions of intermolecular hydrogen atom transfer with the formation of CH2O + C2H5• and CH3OH + C2H3• are less favorable energetically than the consecutive addition of СН3О• to ethylene, isomerization, and decomposition of the adduct with the generation of ethyl radical participating in the chain propagation.