13 C. M. Moore and I. W. M. Smith, J. Chem. Soc., Faraday T rans.,
1995, 91, 3014.
disperse widely. CF CF O radicals will then be formed by the
3
2
reactions of CF CF O radicals either with other peroxy rad-
3
2 2
14 F. S. Fawcett, C. W. Tullock and D. D. Co†men, J. Am. Chem.
Soc., 1962, 84, 4275.
icals or with NO. It seems certain that the overwhelming fate
of CF CF O radicals in the atmosphere will be to fragment to
15 C. M. Moore, I. W. M. Smith and D. W. A. Stewart, Int. J. Chem.
Kinet., 1994, 26, 813.
16 T. J. Wallington, J. Sehested, M. A. Dearth and M. D. Hurley, J.
Photochem. Photobiol. A: Chem., 1993, 70, 5.
17 L. R. Anderson and W. B. Fox, J. Am. Chem. Soc., 1967, 89, 4313.
18 P. G. Thompson, J. Am. Chem. Soc., 1967, 89, 4316.
19 T. J. Wallington, M. D. Hurley, J. Shi, M. M. Maricq, J. Sehested,
O. J. Nielsen and T. Ellermann, Int. J. Chem. Kinet., 1993, 25,
651.
3
2
COF ] CF .
2
3
Although the formation of the trioxides, CF O CF and
3
3
3
CF O C F , will be unimportant in the atmosphere, our ina-
3
3 2 5
bility to model how the observed product yields in the oxida-
tion of CF CF H depend on the [CF CF H] : [F ]. ratio
3
2
3
2
2
and on the O partial pressure is disappointing. It demon-
strates that our knowledge of some of the secondary chemistry
2
in this system is still less than complete.
20 (a) R. Atkinson, D. L. Baulch, R. A. Cox, R. F. Hampson, J. A.
Kerr and J. Troe, J. Phys. Chem. Ref. Data, 1989, 18, 881; (b) R.
Atkinson, D. L. Baulch, R. A. Cox, R. F. Hampson, J. A. Kerr
and J. Troe, J. Phys. Chem. Ref. Data, 1992, 21, 1125; (c) R.
Atkinson, D. L. Baulch, R. A. Cox, R. F. Hampson, J. A. Kerr
and J. Troe, J. Phys. Chem. Ref. Data, 1997, 26, 521; (d) W. B.
Demore, S. P. Sander, D. M. Golden, R. F. Hampson, M. J.
Kurylo, C. J. Howard, A. R. Ravishankara, C. E. Kolb and M. J.
Molina, Chemical Kinetics and Photochemical Data for Use in
Stratospheric Modeling Evaluation Number 11, NASA JPL-
Publication 94-26, 1994.
We thank SERC and NERC for support of our work under
the programme in Laboratory Measurements for Atmospheric
Chemistry. A.H. and C.M.M. are also grateful to the same
bodies for the award of research studentships. We thank Pro-
fessor J. A. Kerr for showing us the latest IUPAC kinetic data
evaluation [ref. 20(c)] prior to publication.
References
21 P. Campuzano-Jost, A. Croce de Cobos, H. Hippler, M. Siefke
and J. Troe, J. Chem. Phys., 1995, 102, 5317.
1
2
3
4
F. S. Rowland and M. J. Molina, Nature (L ondon), 1974, 249, 810.
F. S. Rowland and M. J. Molina, Chem. Eng. News, 1994, 72, 8.
D. J. Weubbles, J. Geophys. Res., 1983, 88, 1433.
ScientiÐc Assessment of Stratospheric Ozone, 1989, vol II; World
Meteorological Organization, Global Ozone Research and Mon-
itoring Project, report no. 20.
R. P. Wayne, Chemistry of Atmospheres, Clarendon Press,
Oxford, 2nd edn., 1991.
A. R. Ravishankara and E. R. Lovejoy, J. Chem. Soc., Faraday
T rans., 1994, 90, 2159.
T. J. Wallington and O. J. Nielsen, in Progress and Problems in
Atmospheric Chemistry, ed. J. R. Barker, World ScientiÐc, Singa-
pore, 1995, ch. 15.
22 M. M. Maricq and J. S. Szente, J. Phys. Chem., 1992, 96, 10 862.
23 O. J. Nielsen, T. Ellerman, J. Sehested, E. Bartkiewicz, T. J. Wall-
ington and M. D. Hurley, Int. J. Chem. Kinet., 1992, 24, 1009.
24 P. Biggs, C. E. Canosa-Mas, J.-M. Fracheboud, C. J. Percival,
R. P. Wayne and D. E. Shallcross, J. Chem. Soc., Faraday T rans.,
1997, 93, 379.
5
6
7
25 (a) R. C. Kennedy and J. B. Levy, J. Phys. Chem., 1972, 76, 3480;
(b) L. Batt and R. Walsh, Int. J. Chem. Kinet., 1982, 14, 933.
26 J. Sehested and T. J. Wallington, Environ. Sci. T echnol., 1993, 27,
146.
27 P. Pagsberg, E. Ratajczak, A. Sillesen and J. T. Jodkowski, Chem.
Phys. L ett., 1987, 141, 88.
8
9
B. Sukornick, Int. J. T hermophys., 1982, 10, 553.
E. O. Edney and D. J. Driscoll, Int. J. Chem. Kinet., 1992, 24,
1067.
28 J. L. Lyman and R. Holland, J. Phys. Chem., 1988, 92, 7232.
29 T. Ellerman, J. Sehested, O. J. Nielsen, P. Pagsberg and T. J.
Wallington, Chem. Phys. L ett., 1994, 218, 287.
10 E. C. Tuazon and R. Atkinson, J. Atmos. Chem., 1993, 16, 301.
11 J. Sehested, T. Ellerman, O. J. Nielsen, T. J. Wallington and
M. D. Hurley, Int. J. Chem. Kinet., 1993, 25, 701.
12 FACSIMILE program; UKAEA Harwell Laboratory, 1987.
Paper 7/02105D; Received 26th March, 1997
J. Chem. Soc., Faraday T rans., 1997, V ol. 93
2699