Issue 38, 2015

Atmospheric chemistry of (CF3)2C[double bond, length as m-dash]CH2: OH radicals, Cl atoms and O3 rate coefficients, oxidation end-products and IR spectra

Abstract

The rate coefficients for the gas phase reactions of OH radicals, k1, Cl atoms, k2, and O3, k3, with 3,3,3-trifluoro-2(trifluoromethyl)-1-propene ((CF3)2C[double bond, length as m-dash]CH2, hexafluoroisobutylene, HFIB) were determined at room temperature and atmospheric pressure employing the relative rate method and using two atmospheric simulation chambers and a static photochemical reactor. OH and Cl rate coefficients obtained by both techniques were indistinguishable, within experimental precision, and the average values were k1 = (7.82 ± 0.55) × 10−13 cm3 molecule−1 s−1 and k2 = (3.45 ± 0.24) × 10−11 cm3 molecule−1 s−1, respectively. The quoted uncertainties are at 95% level of confidence and include the estimated systematic uncertainties. An upper limit for the O3 rate coefficient was determined to be k3 < 9.0 × 10−22 cm3 molecule−1 s−1. In global warming potential (GWP) calculations, radiative efficiency (RE) was determined from the measured IR absorption cross-sections and treating HFIB both as long (LLC) and short (SLC) lived compounds, including estimated lifetime dependent factors in the SLC case. The HFIB lifetime was estimated from kinetic measurements considering merely the OH reaction, τOH = 14.8 days and including both OH and Cl chemistry, τeff = 10.3 days. Therefore, GWP(HFIB,OH) and GWP(HFIB,eff) were estimated to be 4.1 (LLC) and 0.6 (SLC), as well as 2.8 (LLC) and 0.3 (SLC) for a hundred year time horizon. Moreover, the estimated photochemical ozone creation potential (εPOCP) of HFIB was calculated to be 4.60. Finally, HCHO and (CF3)2C(O) were identified as final oxidation products in both OH- and Cl-initiated oxidation, while HC(O)Cl was additionally observed in the Cl-initiated oxidation.

Graphical abstract: Atmospheric chemistry of (CF3)2C [[double bond, length as m-dash]] CH2: OH radicals, Cl atoms and O3 rate coefficients, oxidation end-products and IR spectra

Supplementary files

Article information

Article type
Paper
Submitted
02 Jul 2015
Accepted
03 Sep 2015
First published
07 Sep 2015

Phys. Chem. Chem. Phys., 2015,17, 25607-25620

Author version available

Atmospheric chemistry of (CF3)2C[double bond, length as m-dash]CH2: OH radicals, Cl atoms and O3 rate coefficients, oxidation end-products and IR spectra

V. C. Papadimitriou, C. S. Spitieri, P. Papagiannakopoulos, M. Cazaunau, M. Lendar, V. Daële and A. Mellouki, Phys. Chem. Chem. Phys., 2015, 17, 25607 DOI: 10.1039/C5CP03840E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements