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The gas-phase reaction products of 2-fluoropropene (2FP) with Cl atoms have been determined for the first time at 298 K and atmospheric pressure using a 1080 L quartz-glass photoreactor coupled with in situ FTIR spectroscopy to monitor reactants and products. Acetyl fluoride and formyl chloride were observed as the main products with yields of (106 ± 10)% and (100 ± 11)%, respectively. Electronic structure calculations of reactants, intermediates, products and transition states on a detailed mechanism of the reaction were performed by DFT procedures (BMK, M06, M062X/D3), as well as accurate composite methods on both the addition and abstraction reaction channels. From the joint experimental and theoretical studies, we concluded that the reaction occurs primarily via addition to the Cα carbon, with a smaller participation of the addition on the Cβ carbon, which is not produced directly from the separated reactants but from the CH3CFCH2Cl intermediate radical through a submerged transition state. The abstraction channel occurs at larger energies than the addition ones, and also presents a submerged transition state, with a lower barrier. No products arising from this channel are expected. The proposed mechanism explains also why formaldehyde, predicted as a product by former theoretical studies, is not found among the experimental products. The atmospheric implications of the reaction products are assessed. [ABSTRACT FROM AUTHOR]

A product study of the reactions of ( E / Z )-1,2,3,3,3-pentafluoropropene (( E / Z )-CF 3 CF[double bond, length as m-dash]CHF) and hexafluoroisobutylene ((CF 3 ) 2 C[double bond, length as m-dash]CH 2 ) initiated by Cl atoms were developed at 298 ± 2 K and atmospheric pressure. The experiments were carried out in a 1080 L quartz-glass environmental chamber coupled via in situ FTIR spectroscopy to monitor the reactants and products. The main products observed and their yields were as follows: CF 3 C(O)F (106 ± 9)% with HC(O)F (100 ± 8)% as a co-product for ( E / Z )-CF 3 CF[double bond, length as m-dash]CHF, and CF 3 C(O)CF 3 (94 ± 5)% with HC(O)Cl (90 ± 7)% as a co-product for (CF 3 ) 2 C[double bond, length as m-dash]CH 2 . Atmospheric implications of the end-product degradation are assessed in terms of their impact on ecosystems to help environmental policymakers consider HFOs as acceptable replacements., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The OH radical initiated photodegradation of 2-fluoropropene (CH 3 CF[double bond, length as m-dash]CH 2 ), 3,3,3-trifluoro-2-(tri-fluoromethyl)propene ((CF 3 ) 2 C[double bond, length as m-dash]CH 2 ) and ( E / Z )-1,2,3,3,3-pentafluoropropene (( E / Z )-CF 3 CF[double bond, length as m-dash]CHF) has been investigated for the first time using a 1080 L quartz-glass environmental chamber at 298 ± 2 K and atmospheric pressure of synthetic air coupled with in situ FTIR spectroscopy to monitor reactants and products. The major products observed in the OH reaction were CH 3 C(O)F (98 ± 5)% together with HC(O)H (89 ± 7)% as a co-product, CF 3 C(O)F (103 ± 8)% together with HC(O)F (96 ± 7)% as a co-product and CF 3 C(O)CF 3 (91 ± 8)% together with HC(O)H (98 ± 12)% as a co-product from the C 1 -C 2 bond cleavage channel of the intermediate hydroxyalkoxy radical, formed by addition of OH to the terminal carbon of the double bond which is designated C 1 of 2-fluoropropene, ( E / Z )-1,2,3,3,3-pentafluoropropene and 3,3,3-trifluoro-2-(tri-fluoromethyl)propene, respectively. The present results are compared with previous studies for the reaction of OH with the separate isomers ( E ) and ( Z ) of 1,2,3,3,3-pentafluoropropene. In addition, atmospheric implications of the reactions studied are discussed., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Rate coefficients for the gas-phase reactions of Cl atoms with β-ocimene and camphene were determined to be (in units of 10 -10 cm 3 per molecule per s) 5.5 ± 0.7 and 3.3 ± 0.4, respectively. The experiments were performed by the relative technique in an environmental chamber with FTIR detection of the reactants at 298 K and 760 torr. Product identification experiments were carried out by gas chromatography with mass spectrometry detection (GC-MS) using the solid-phase microextraction (SPME) method employing on-fiber carbonyl compound derivatization with o -(2,3,4,5,6-pentafluorobenzyl) hydroxylamine hydrochloride. An analysis of the available rates of addition of Cl atoms and OH radicals to the double bond of alkenes and cyclic and acyclic terpenes with a conjugated double bond at 298 K is presented. The atmospheric persistence of these compounds was calculated taking into account the measured rate coefficients. In addition, tropospheric chemical mechanisms for the title reactions are postulated., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)