Correction of C (O) F2 Yields in “Atmospheric Chemistry of (CF3

Correction of C(O)F2 Yields in “Atmospheric Chemistry of (CF3)2CHOCH3, (CF3)2CHOCHO, and CF3C(O)OCH3”. Freja From Østerstrøm, Timothy J...
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Correction of C(O)F2 Yields in “Atmospheric Chemistry of (CF3)2CHOCH3, (CF3)2CHOCHO, and CF3C(O)OCH3” Freja From Østerstrøm, Timothy J. Wallington,* Mads P. Sulbaek Andersen, and Ole John Nielsen J. Phys. Chem. A 2015, 119 (42), 10540−10552. DOI: 10.1021/acs.jpca.5b08204 We discovered an error in the calculation of the COF2 yields from experiments at CCAR reported in our paper. An incorrect calibration for the reference spectrum of C(O)F2 was used to calculate the yield of this species. This error does not affect COF2 yields calculated in our previous experiments at Ford. The error has been corrected and the COF2 yields have been recalculated for the following reactions described in the paper: (CF3)2 CHOCH3 + OH → products

(1)

(CF3)2 CHOCHO + Cl → products

(2)

CF3C(O)OCH3 + Cl → products

(3)

The associated product yield figures and Figures 5, 8, and 11 have been updated to reflect the recalculated COF2 yields and are given here.

Figure 8. Observed concentration of CF3C(O)OCHO (squares), CF3C(O)CF3 (circles), and C(O)F2 (triangles) normalized to the initial (CF3)2CHOCHO concentration vs the fractional loss of (CF3)2CHOCHO following UV irradiation of mixtures containing (CF3)2CHOCHO and Cl2 in 700 Torr O2 (solid symbols) or air (open symbols).

Figure 5. Observed concentration of (CF3)2CHOCHO (squares), C(O)F2 (triangles), CF3C(O)OCH3 (circles), and CF3C(O)CF3 (diamonds), normalized to the initial (CF3)2CHOCH3 concentration, vs the fractional loss of (CF3)2CHOCH3 following UV irradiation of mixtures of (CF3)2CHOCH3, H2, and O3 in 200 Torr air (open symbols), 200 Torr O2 (gray symbols), or 700 Torr of air (solid symbols). The lines are fits to the data, see text for details. Figure 11. Observed concentration of CF3C(O)OCHO (squares) and C(O)F2 (triangles) normalized to the initial concentration of CF3C(O)OCH3 vs the fractional loss of CF3C(O)OCH3 following UV irradiation of CF3C(O)OCH3/Cl2 mixtures in 700 Torr O2/N2. The O2 partial pressures were 17 Torr (open symbols), 140 Torr (gray symbols), and 700 Torr (solid symbols). The lines are fits to the data, see text for details.

The reported yield of C(O)F2 in reaction 1 has been corrected from 45 ± 5% to 12 ± 1%, with the other products being (CF3)2CHOCHO, CF3C(O)OCH3, and CF3C(O)CF3 in yields of 76 ± 8%, 16 ± 2%, and 4 ± 1%, respectively. In a similar fashion, the yield of COF2 in reaction 2 has been corrected from 118 ± 12% to 30 ± 3%, with the coproducts being CF3C(O)CF3 and CF3C(O)OCHO in yields of 67 ± 7% and 28 ± 3%, respectively. The yields of CF3C(O)OCHO and © 2016 American Chemical Society

Published: September 30, 2016 7987

DOI: 10.1021/acs.jpca.6b09344 J. Phys. Chem. A 2016, 120, 7987−7988

The Journal of Physical Chemistry A

Addition/Correction

C(O)F2 in reaction 2 are indistinguishable within the experimental uncertainties, which is consistent with the degradation mechanism shown in Figure 13. Finally, the formation of C(O)F2 in reaction 3 is shown in the corrected version of Figure 11. The curvature in the COF2 data in Figure 11 indicates this species is formed as a secondary product in the system.



AUTHOR INFORMATION

Notes

Ford Motor Company (Ford) does not expressly or impliedly warrant, nor assume any responsibility, for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed nor represent that its use would not infringe the rights of third parties. Reference to any commercial product or process does not constitute its endorsement. This article does not provide financial, safety, medical, consumer product, or public policy advice or recommendation. Readers should independently replicate all experiments, calculations, and results. The views and opinions expressed are of the authors and do not necessarily reflect those of Ford. This disclaimer may not be removed, altered, superseded or modified without prior Ford permission.

7988

DOI: 10.1021/acs.jpca.6b09344 J. Phys. Chem. A 2016, 120, 7987−7988