Novel CFCs-substitutes recommended by EPA (hydrofluorocarbon-245fa and hydrofluoroether-7100): Ion chemistry in air plasma and reactions with atmospheric ions

  • Ester Marotta
  • Cristina Paradisi
  • R. Graham Cooks


The ion chemistry of the title compounds, a nonafluorobutyl methyl ether and a hydrofluoropropane, is elucidated by a combination of studies using atmospheric pressure ionization mass spectrometry and triple quadrupole mass spectrometry. In the positive ion mode, the hydrofluoroether readily forms an [M−F]+ ion, attributable to hydronium ion induced dehydrofluorination, the product of which can be further hydrated to give a protonated hydrofluoroester. By contrast, the hydrofluoropropane does not react with the hydronium ion but rather gives hydrofluoroalkenylium cations via H atom and F atom abstraction by the dioxygen radical cation. In the negative ion mode, the fluorobutyl methyl ether undergoes dissociative electron capture with O2−·, O2−·(H2O), O3−·, and NO2 to generate the fluorobutoxy anion, which can dissociate by CF2=O loss to give the perfluorocarbanion when the precursor ions are internally excited. The hydrofluoropropane reacts readily with common atmospheric anions to form molecular complexes with F, O2−·, and O3−· and the strongly H-bonded species, O2−·(HF) and F(HF). Interestingly, isomeric pentafluoropropanes form in the reaction with O2−·, either O2−·(HF) or F(HF), depending on the specific pattern of the fluoro substitution.


  1. 1.
    Atmospheric Chemistry and Physics. From Air Pollution to Climate Change; Seinfeld, J. H.; Pandis, S. N., eds.; John Wiley and Sons: New York, 1998.Google Scholar
  2. 2.(a)
    Vercammen, K. L. L.; Berezin, A. A.; Lox, F.; Chang J. S. Nonthermal Plasma Techniques for the Reduction of VOC in Air Streams: A Critical Review. J. Adv. Oxid. Technol 1997, 2, 312–329Google Scholar
  3. 2.(b)
    Odic, E.; Paradisi, C.; Rea, M.; Parissi, L.; Goldman, A.; Goldman M. Treatment of Organic Pollulants by Corona Discharge Plasma. In The Modern Problems of Electrostatics with Applications in Environment Protection; NATO Science Series, 2. Environmental Security, Vol. LXIII, Inculet, I. I.; Tanasescu, F. T.; Cramariuc, R., Eds.; Kluwer Academic Publishers: Dordrecht, 1999; p 143.Google Scholar
  4. 3.
    Donò, A.; Paradisi, C.; Scorrano G. Abatement of Volatile Organic Compounds by Corona Discharge: A Study of the Reactivity of Trichloroethylene Under Atmospheric Pressure Ionization Conditions. Rapid Commun. Mass Spectrom. 1997, 11, 1687–1694.CrossRefGoogle Scholar
  5. 4.
    Nicoletti, A.; Paradisi, C.; Scorrano G. Ion Chemistry of Chloroethanes in Air at Atmospheric Pressure. Rapid Commun. Mass. Spectrom. 2001, 15, 1904–1911.CrossRefGoogle Scholar
  6. 5.
    Bosa, E.; Paradisi, C.; Scorrano G. Positive and Negative Gas-Phase Ion Chemistry of Chlorofluorocarbons in Air at Atmospheric Pressure. Rapid Commun. Mass Spectrom. 2003, 17, 1–8.CrossRefGoogle Scholar
  7. 6.
    Marotta, E.; Paradisi, C.; Scorrano G. An APCI Study of the Positive and Negative Ion Chemistry of Hydrofluorocarbons 1,1-Difluoroethane (HFC-152a) and 1,1,1,2-Tetrafluoroethane (HFC-134a) and of Perfluoro-n-Hexane (FC-72) in Air Plasma at Atmospheric Pressure. J. Mass Spectrom. 2004, 39, 791–801.CrossRefGoogle Scholar
  8. 7.
    Marotta, E.; Bosa, E.; Scorrano, G.; Paradisi C. Positive and Negative Ion Chemistry of the Anesthetic Halothane (1-Bromo-1-Chloro-2,2,2-Trifluoroethane) in Air Plasma at Atmospheric Pressure. Rapid Commun. Mass Spectrom. 2005, 19, 391–396.CrossRefGoogle Scholar
  9. 8.
    Protection of Stratospheric Ozone: Notice 16 for Significant New Alternatives Policy Program. Environmental Protection Agency, U. S. Environmental Protection Agency, Washington, DC, U.S.A. Federal Register 2002, 67(56), 13272–13278.Google Scholar
  10. 9.
    Heck, A. J. R.; de Koning, L. J.; Nibbering M. M. Gas-Phase Bimolecular Chemistry of Isomeric Cyclic Ethylenehalonium and α-Haloethyl Cations. Org. Mass Spectrom. 1993, 28, 235–244.CrossRefGoogle Scholar
  11. 10.(a)
    Carbini, M.; Conte, L.; Gambaretto, G.; Catinella, S.; Traldi P. Mass Spectrometry of Some Fluorinated Alcohols. Org. Mass Spectrom 1992, 27, 1248–1254.CrossRefGoogle Scholar
  12. 10.(b)
    Tajima, S.; Shirai, T.; Tobita, S.; Nibbering N. M. M. Loss of Hydrogen Fluoride from Metastable C2H2F3O+ ions generated from some fluorinated aliphatic alcohols. Org. Mass Spectrom 1993, 28, 473–474.CrossRefGoogle Scholar
  13. 10.(c)
    Várnai, P.; Nyulászi, L.; Veszprémi, T.; Vékey K. Loss of Hydrogen Fluoride from C2H2F3O+: A Theoretical Study of a Reaction Mechanism. Chem. Phys. Lett 1995, 233, 340–346.CrossRefGoogle Scholar
  14. 10.(d)
    Sekiguchi, O.; Watanabe, D.; Nakajima, S.; Tajima, S.; Uggerud E. Loss of HF from C2H4FO+ Produced from 2-Hydroxy-2-Trifluoromethylpropanoic Acid Upon Electron Ionization. Int. J. Mass Spectrom 2003, 222, 1–9.CrossRefGoogle Scholar
  15. 11.
    Nguyen, V.; Mayer, P. S.; Morton T. H. Intramolecular Fluorine Migration via Four-Member Cyclic Transition States. J. Org. Chem. 2000, 65, 8032–8040.CrossRefGoogle Scholar
  16. 12.
    Lias, S. G. Ionization Energy Evaluation. In NIST Chemistry WebBook, NIST Standard Reference Database No. 69; Maillard, W. G.; Linstrom, P. J., Eds.; National Institute of Standards and Technology: Gaithersburg, MD;, 2004.Google Scholar
  17. 13.(a)
    Knighton, W. B.; Zook, D. R.; Grimsrud E. P. Cluster-Assisted Decomposition Reactions of the Molecular Anions of SF6 and C7F14. J. Am. Soc. Mass Spectrom. 1990, 1, 372–381.CrossRefGoogle Scholar
  18. 13.(b)
    Arnold, S. T.; Viggiano A. A. A Turbulent Ion Flow Tube Study of the Cluster-Mediated Reactions of SF6 with H2O, CH3OH, and C2H5OH from 50 to 500 Torr. J. Phys. Chem. A 2001, 105, 3527–3531.CrossRefGoogle Scholar
  19. 14.
    Wenthold, P. G.; Squires R. R. Bond Dissociation Energies of F2 and HF2: A Gas-Phase Experimental and G2 Theoretical Study. J. Phys. Chem. 1995, 99, 2002–2005.CrossRefGoogle Scholar
  20. 15.
    Morris, R. A.; Viggiano, A. A.; Arnold, S. T.; Paulson J. F. Reactions of Atmospheric Ions with Selected Hydrofluorocarbons. J. Phys. Chem. 1995, 99, 5992–5999.CrossRefGoogle Scholar

Copyright information

© American Society for Mass Spectrometry 2005

Authors and Affiliations

  • Ester Marotta
    • 1
    • 2
  • Cristina Paradisi
    • 1
  • R. Graham Cooks
    • 2
  1. 1.INTM del CNR—Sezione di Padova, Dipartimento di Scienze ChimicheUniversità di PadovaPadovaItaly
  2. 2.Department of ChemistyPurdue UniversityWest LafayetteUSA
  3. 3.Dipartamento di Scienze ChimicheUniversità di PadovaPadovaItaly

Personalised recommendations