Understanding the insight into the mechanisms and dynamics of the Cl-initiated oxidation of (CH3)3CC(O)X and the subsequent reactions in the presence of NO and O2 (XÂ =Â F, Cl, and Br)

- We studied mechanism of Cl-initiated oxidation of (CH3)3CC(O)X (X = F, Cl, and Br).
- The total rate constants are computed for (CH3)3CC(O)X (X = F, Cl, and Br) at 298 K.
- Atmospheric lifetimes and GWPs for (CH3)3CC(O)X (X = F, Cl, and Br) are estimated.
- The subsequent reactions may produce organic aerosol in the presence of O2/NO.

In this work, the density functional and high-level ab initio theories are adopted to investigate the mechanisms and kinetics of reaction of (CH3)3CC(O)X (X = F, Cl, and Br) with atomic chlorine. Rate coefficients for the reactions of chlorine atom with (CH3)3CC(O)F (k1), (CH3)3CC(O)Cl (k2), and (CH3)3CC(O)Br (k3) are calculated using canonical variational transition state theory coupled with small curvature tunneling method over a wide range of temperatures from 250 to 1000 K. The dynamic calculations are performed by the variational transition state theory with the interpolated single-point energies method at the CCSD(T)/aug-cc-pVDZ//B3LYP/6-311++G(d,p) level of theory. Computed rate constant is in good line with the available experimental value. The rate constants for the title reactions are in this order: k1

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