Atmospheric Chemistry of (CF)CF-C≡N: A Replacement Compound for the Most Potent Industrial Greenhouse Gas, SF

FTIR/smog chamber experiments and ab initio quantum calculations were performed to investigate the atmospheric chemistry of (CF)CFCN, a proposed replacement compound for the industrially important sulfur hexafluoride, SF. The present study determined k(Cl + (CF)CFCN) = (2.33 ± 0.87) × 10, k(OH + (CF)CFCN) = (1.45 ± 0.25) × 10, and k(O + (CF)CFCN) ≤ 6 × 10 cm molecule s, respectively, in 700 Torr of N or air diluent at 296 ± 2 K. The main atmospheric sink for (CF)CFCN was determined to be reaction with OH radicals. Quantum chemistry calculations, supported by experimental evidence, shows that the (CF)CFCN + OH reaction proceeds via OH addition to -C(≡N), followed by O addition to -C(OH)═N·, internal H-shift, and OH regeneration. The sole atmospheric degradation products of (CF)CFCN appear to be NO, COF, and CFC(O)F. The atmospheric lifetime of (CF)CFCN is approximately 22 years. The integrated cross section (650-1500 cm) for (CF)CFCN is (2.22 ± 0.11) × 10 cm molecule cm which results in a radiative efficiency of 0.217 W m ppb. The 100-year Global Warming Potential (GWP) for (CF)CFCN was calculated as 1490, a factor of 15 less than that of SF.