OH + (E)- and (Z)-1-Chloro-3,3,3-trifluoropropene-1 (CF₃CH═CHCl) Reaction Rate Coefficients: Stereoisomer-Dependent Reactivity

Abstract

Rate coefficients for the gas-phase reaction of the OH radical with (E)- and (Z)-CF3CH═CHCl (1-chloro-3,3,3-trifluoropropene-1, HFO-1233zd) (k1(T) and k2(T), respectively) were measured under pseudo-first-order conditions in OH over the temperature range 213-376 K. OH was produced by pulsed laser photolysis, and its temporal profile was measured using laser-induced fluorescence. The obtained rate coefficients were independent of pressure between 25 and 100 Torr (He, N2) with k1(296 K) = (3.76 ± 0.35) × 10(-13) cm(3) molecule(-1) s(-1) and k2(296 K) = (9.46 ± 0.85) × 10(-13) cm(3) molecule(-1) s(-1) (quoted uncertainties are 2σ and include estimated systematic errors). k2(T) showed a weak non-Arrhenius behavior over this temperature range. The (E)- and (Z)- stereoisomer rate coefficients were found to have opposite temperature dependencies that are well represented by k1(T) = (1.14 ± 0.15) × 10(-12) exp[(-330 ± 10)/T] cm(3) molecule(-1) s(-1) and k2(T) = (7.22 ± 0.65) × 10(-19) × T(2) × exp[(800 ± 20)/T] cm(3) molecule(-1) s(-1). The present results are compared with a previous room temperature relative rate coefficient study of k1, and an explanation for the discrepancy is presented. CF3CHO, HC(O)Cl, and CF3CClO, were observed as stable end-products following the OH radical initiated degradation of (E)- and (Z)-CF3CH═CHCl in the presence of O2. In addition, chemically activated isomerization was also observed. Atmospheric local lifetimes of (E)- and (Z)-CF3CH═CHCl, due to OH reactive loss, were estimated to be ∼34 and ∼11 days, respectively. Infrared absorption spectra measured in this work were used to estimate radiative efficiencies and well-mixed global warming potentials of ∼10 and ∼3 for (E)- and (Z)-CF3CH═CHCl, respectively, on the 100-year time horizon.

Updated Global Warming Potentials and Radiative Efficiencies of Halocarbons and Other Weak Atmospheric Absorbers

“…Absorption spectra from the PNNL database were added for four HCFCs in H2013 (HCFC‐21, HCFC‐123, HCFC‐123a, and HCFC‐124); the new RE values are in good agreement (difference of 5% or less) with the H2013 values (Tables 5 and S8). The spectrum from Gierczak et al (2014) has been added for HCFO‐1233zd(E), but the increased RE value since H2013 is mainly due to the longer lifetime and is therefore less influenced by the lifetime‐correction factor.…”

“…Reviews of Geophysics 3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-Pentadecafluorononan-1-ol CF 3 (CF 2 ) 6 CH 2 CH 2 OH 755-02-2 17.0 days 0.07 0.06 1 <1 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11, (Tables 5 and S8). The spectrum from Gierczak et al (2014) has been added for HCFO-1233zd(E), but the increased RE value since H2013 is mainly due to the longer lifetime and is therefore less influenced by the lifetime-correction factor.…”

Rate Coefficient Measurements and Theoretical Analysis of the OH + (E)-CF3CH═CHCF3 Reaction

“…Provided the reactant and reference compounds are lost solely via the OH reaction the rate coefficients for the two reactions are related by 6 Several experiments were performed using CH 3 CH 2 Cl as the reference compound; however, deviations from eq II, which we attribute to secondary Cl-atom chemistry, were observed and particularly noticeable at higher extent of reaction. 12 Results using CH 3 CH 2 Cl as the reference compound were not included in the final analysis. The apparatus used for the relative rate measurements has been described elsewhere.…”

Insight and performance of LC‐DFT vs DFT in the NMR shielding and chemical shift calculations: Case of CHClCHCF3

“…[ 44 ] Their lifetimes are 14 and 26 days for cis ‐ and trans ‐CTFP, respectively. [ 39–41 ] In addition, the UV‐vis and IR spectroscopies of these two stereoisomers have been intensively studied experimentally and theoretically [ 39–41,43 ] in order to obtain better information on their electronic and backbone structures and to find their radiative forcing efficiency and the global warming potential parameters. So far, no study has been conducted with regard to the NMR spectroscopy.…”

“…They are also intended for use as a foam-blowing agent and a preceding cleaning agent for special applications. [38][39][40][41][42][43] In fact, such molecules are known as short-lived compounds as they contain the carbon-carbon double bond (C C) in their structure. [44] Their lifetimes are 14 and 26 days for cis-and trans-CTFP, respectively.…”