Atmospheric Chemistry of 1H-Heptafluorocyclopentene (cyc-CFCFCFCF═CH-): Rate Constant, Products, and Mechanism of Gas-Phase Reactions with OH Radicals, IR Absorption Spectrum, Photochemical Ozone Creation Potential, and Global Warming Potential.

The rate constant for gas-phase reactions of OH radicals with 1H-heptafluorocyclopentene (cyc-CFCFCFCF═CH-) was measured using a relative rate method at 298 K: (5.20 ± 0.09) × 10 cm molecule s. The quoted uncertainty includes two standard deviations from the least-squares regression, the systematic error from the GC analysis, and the uncertainties of the rate constants of the reference compounds. The OH-radical-initiated oxidation of cyc-CFCFCFCF═CH- gives the main products COF, CO, and CO, leading to negligible environmental impact. For consumptions of cyc-CFCFCFCF═CH- of less than 54%, the yield of the formation of ([COF] + [CO] + [CO])/5 (based on the conservation of carbon) was 0.99 ± 0.02, which is very close to 100%. A possible degradation mechanism was proposed. The radiative efficiency (RE) of cyc-CFCFCFCF═CH- measured at room temperature was 0.215 W m ppb. The atmospheric lifetime of cyc-CFCFCFCF═CH- was calculated as 0.61 year, and the photochemical ozone creation potential (POCP) was negligible. The 20-, 100-, and 500-year time horizon global warming potentials (GWPs) were estimated as 153, 42, and 12, respectively.