Computational Study of the Reaction Mechanism and Kinetics of CH3CHC(CH3)COOCH3 Ozonolysis

The reaction mechanism for the ozonolysis of trans-CH3CHC(CH3)COOCH3 as well as the isomerization reaction of CH3CHOO and CH3OC(O)C(CH3)OO) without and with a water molecule were investigated at the G3B3 level. The profile of the potential energy surface (PES) was constructed. Adding ozone to trans-CH3CHC(CH3)COOCH3 via a cyclic transition state to produce a highly unstable primary ozonide that can decompose readily to form P1 (CH3CHOO+CH3OC(O)C(CH3)O) and P2 (CH3CHO+ CH3OC(O)C(CH3)OO) because the bond breaks in different positions. The total rate constants over the temperature range of 200-1200 K are obtained using the conventional transition state theory with Wigner tunneling correction. The calculated rate constant is 7.55×10 - 18 cm 3 ∙molecule - 1 ∙s - 1 at 294 K, in good agreement with previous experimental data for similar reactions. The isomerization reaction of CH3CHOO and CH3OC (O)C(CH3)OO) with a water molecule can occur via α-addition process and β-hydrogen transfer mechanism. The former is more favorable than the latter. Compared with the naked isomerization reactions of CH3CHOO and CH3OC(O)C(CH3)OO), the presence of water molecules makes isomerization reactions