Cl
atom initiated photo-oxidation of monochlorinated propanes to
form the carbonyl compounds was investigated. Propionaldehyde and
acetone were identified to be major products in the oxidation of 1-chloropropane
and 2-chloropropane, respectively. The complete product analyses were
carried out using gas chromatography–mass spectrometry (GC–MS)
and gas chromatography–infrared spectroscopy (GC–IR)
as analytical tools, and an appropriate oxidation mechanism was proposed
on the basis of the product analyses. The temperature dependent rate
coefficients for the reactions of Cl atoms with 1-chloropropane (1-CP)
and 2-chloropropane (2-CP) were measured experimentally in the gas
phase, using the relative rate method in the temperature range 268–363
K and at 1 atm pressure. Ethane, ethylene, and ethyl acetate were
used as reference compounds. The obtained rate coefficients for the
reactions of Cl atoms with 1-CP and 2-CP at room temperature (298
K) and at 1 atm pressure were (4.64 ± 0.70) × 10–11 and (2.57 ± 0.44) × 10–11 cm3 molecule–1 s–1, respectively.
Furthermore, to complement our experimentally obtained results, computational
calculations were performed for these reactions using canonical variational
transition state theory (CVT) with small curvature tunneling (SCT)
in combination with the CCSD/cc-pVDZ//MP2/6-31+G(d,p) level of theory.
Detailed discussion on feasibility of the reactions, branching ratios,
degradation mechanism, and atmospheric implications are discussed
in this manuscript.