Reactivity of hydrohaloethers with OH radicals and chlorine atoms: Correlation with molecular properties

- C-H bond energies and ionization potentials of hydrochloroethers are calculated.
- Reactivity of hydrohaloethers with OH radicals and Cl atoms is evaluated.
- Correlations between rate coefficients and molecular properties are established.
- Atmospheric implications of hydrohaloethers are briefly discussed.

The reactivity of halogenated ethers, especially hydrochloroethers, with hydroxyl radicals and chlorine atoms was studied by correlating the room-temperature rate coefficients with both the C-H bond dissociation energies and the vertical ionization potentials of the parent molecules. These molecular properties were estimated at the composite G3B3 level of theory. The results suggest that Cl-substituted ethyl-methyl-ethers and ethyl-ethyl-ethers at the β-position tend to raise the activating effect of the ether linkage -O- and to enhance the possibility of the abstraction of H atoms bonded to α-carbon. Derived relationships between the rate coefficients (in cm3 molecule−1 s−1) and ionization potentials (in eV): log kOH = −(1.248 ± 0.065) IP + (1.06 ± 0.73) and log kCl = −(1.46 ± 0.12) IP + (4.5 ± 1.3) allows, in average, to estimate rate coefficients within a factor of 2-3. The atmospheric implications of halogenated and hydrogenated ethers are briefly discussed on the basis of their estimated global lifetimes.