Journal Details

1. Cl Atom Initiated Photo-Oxidation Reactions of Vinyl Trifluoroacetate and Allyl Trifluoroacetate in the Tropospheric Conditions.

R. Kaipara & B. Rajakumar.  J. Phys. Chem, 2020, 124 (11), 2123-2139.

Relative rate (RR) technique coupled with gas chromatography (GC) was used to investigate the kinetics of the reactions of two hydrofluoroesters (allyl trifluoroacetate (CF3C(O)OCH2CH═CH2, ATFA) and vinyl trifluoroacetate (CF3C(O)OCH═CH2, VTFA)) with Cl atoms between 268 and 363 K and at 760 Torr of N2 (or air). The temperature-dependent Arrhenius expressions for the title reactions were obtained to be k268–363KVTFA+Cl = [(7.83 ± 2.26) × 10–12 exp((974 ± 89)/T)] cm3 molecule–1 s–1 and k268–363KATFA+Cl = [(9.03 ± 1.92) × 10−12 exp((883 ± 65)/T)] cm3 molecule–1 s–1, respectively. A negative temperature dependency was observed for both the reactions. In addition to this, the kinetics of the studied reactions was evaluated computationally at the CCSD(T)/cc-pVTZ//MP2/6-311++G(d,p) level of theory in the temperature range of 200–400 K using canonical variational transition (CVT) state theory in conjunction with small curvature tunneling (SCT) corrections and interpolated single point energy (ISPE) methods. The product analysis of the reactions of VTFA and ATFA with Cl atoms in the presence of O2 was also investigated using gas chromatography–mass spectrometry (GC-MS) and gas chromatography–infrared spectroscopy (GC-IR). The plausible oxidation mechanism of the title reactions was proposed based on the product analyses. Further, to comprehend the impact of these molecules on the troposphere, atmospheric lifetimes, lifetime-corrected radiative forcing (RF), and global warming potential (GWP) were estimated and are presented in this manuscript.