Theoretical Study on Reaction Pathways of Methyl Radical with Ethylamine

The mechanisms for the reaction of methyl radical with ethylamine were determined by the density functional theory using the atomic structures of the reactants, transition states and products optimized at the B3LYP/6-311++G(3df,2p) level of theory. Seven transition states were identified for the production of CH3CHNH2 + CH4 (TS1), CH3CH2NH + CH4 (TS2), CH2CH2NH2 + CH4 (TS3), CH3CH2NHCH3 + H (TS4), CH3CH2 + CH3NH2 (TS5), C2H6 + CH2NH2 (TS6) and C3H8 + NH2 (TS7) with the corresponding barriers, 9.34, 9.90, 13.46, 27.70, 39.12, 45.82 and 69.34 kcal/mol. Thermodynamics analysis and potential energy surface showed that H-abstraction pathways take place easier than NH2-, CH3–abstractions, H-substitution of the NH2 group and CH3-substitution in ethylamine. The H-abstraction in methylene group of ethylamine is the most favourable on the PES of this reaction system. 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