title: Atmospheric Chemistry of (CF3)2CF-C≡N: A Replacement Compound for the Most Potent Industrial Greenhouse Gas, SF6.
abstract: FTIR/smog chamber experiments and ab initio quantum calculations were performed to investigate the atmospheric chemistry of (CF3)2CFCN, a proposed replacement compound for the industrially important sulfur hexafluoride, SF6. The present study determined k(Cl + (CF3)2CFCN) = (2.33 ± 0.87) × 10-17, k(OH + (CF3)2CFCN) = (1.45 ± 0.25) × 10-15, and k(O3+ (CF3)2CFCN) ≤ 6 × 10-24cm3molecule-1s-1, respectively, in 700 Torr of N2or air diluent at 296 ± 2 K. The main atmospheric sink for (CF3)2CFCN was determined to be reaction with OH radicals. Quantum chemistry calculations, supported by experimental evidence, shows that the (CF3)2CFCN + OH reaction proceeds via OH addition to -C(≡N), followed by O2addition to -C(OH)═N·, internal H-shift, and OH regeneration. The sole atmospheric degradation products of (CF3)2CFCN appear to be NO, COF2, and CF3C(O)F. The atmospheric lifetime of (CF3)2CFCN is approximately 22 years. The integrated cross section (650-1500 cm-1) for (CF3)2CFCN is (2.22 ± 0.11) × 10-16cm2molecule-1cm-1which results in a radiative efficiency of 0.217 W m-2ppb-1. The 100-year Global Warming Potential (GWP) for (CF3)2CFCN was calculated as 1490, a factor of 15 less than that of SF6.
authors.affiliation: Department of Chemistry and Biochemistry, California State University , Northridge, California 91330, United States.|Copenhagen Center for Atmospheric Research, Department of Chemistry, University of Copenhagen , 2100 Copenhagen Ø, Denmark.
authors.forename: Mads P
authors.identifier: 0000-0002-7976-5852
authors.initials: MP
authors.lastname: Sulbaek Andersen
authors.affiliation: Copenhagen Center for Atmospheric Research, Department of Chemistry, University of Copenhagen , 2100 Copenhagen Ø, Denmark.
authors.forename: Mildrid
authors.initials: M
authors.lastname: Kyte
authors.affiliation: Copenhagen Center for Atmospheric Research, Department of Chemistry, University of Copenhagen , 2100 Copenhagen Ø, Denmark.
authors.forename: Simone Thirstrup
authors.initials: ST
authors.lastname: Andersen
authors.affiliation: Department of Chemistry, University of Oslo , P.O. Box 1033, Blindern, 0315 Oslo, Norway.
authors.forename: Claus J
authors.initials: CJ
authors.lastname: Nielsen
authors.affiliation: Copenhagen Center for Atmospheric Research, Department of Chemistry, University of Copenhagen , 2100 Copenhagen Ø, Denmark.
authors.forename: Ole John
authors.initials: OJ
authors.lastname: Nielsen
mesh_terms: D002713:Chlorine / Q000737:chemistry*; D057232:Global Warming; D017665:Hydroxyl Radical / Q000737:chemistry*
chemical_list: D017665:Hydroxyl Radical; D002713:Chlorine