IUPAC Subcommittee on Gas Kinetic Data Evaluation

Providing evaluated kinetic data on the web since 1999.

IUPAC Subcommittee on Gas Kinetic Data Evaluation

Website: http://www.iupac-kinetic.ch.cam.ac.uk/ See website for latest evaluated data. Datasheets can be downloaded for personal use only and must not be retransmitted or disseminated either electronically or in hardcopy without explicit written permission.

This datasheet last evaluated: 2003-06-12 ; last change in preferred values: 2003-06-12 ; last peer-reviewed publication: 2006-09-06


CH3C(O)O2NO2 + MCH3C(O)O2 + NO2 + M(1) Δ Hο = 119 kJ mol-1

Rate Coefficient Data: Low-pressure rate coefficients

Absolute Rate Coefficients

Rate Coefficient (k0) / Temperature / ReferenceTechniques and Comments
s-1Kelvin
(4.9 ± 0.3) × 10 -3 exp(-12100/T)[N 2 ]300–330Bridier et al., 1991FTIR (a)
1.1 × 10 -20 [N 2 ]298*

Comments

(a) Rate of the thermal decomposition of CH 3 C(O)OONO 2 (PAN) measured by FTIR absorption spectroscopy in the presence of an excess of NO to scavenge CH 3 CO 3 radicals. Pressure range 10 mbar to 790 mbar of N 2 . Falloff curves were analyzed with F c =0.30.

Preferred Values

k0s-1{1.1-20 N_2[N2] 1.1×10-20 ±0.3 N_2[N2]   if   T 298 4.9-3PlusMinus -121001000 T N_2[N2]4.9×10-3exp( -12100±1000)/T N_2[N2]  if   300 T 330

Comments on Preferred Values

The data base of Bridier et al. (1991) is large enough to allow for a falloff extrapolation to k 0 , in part because falloff curves for PAN dissociation and recombination were measured independently. Falloff extrapolations were made with a modeled value of F c =0.3; see the evaluation of the data from Bridier et al. (1991) in Zabel (1995).

Rate Coefficient Data: High-pressure rate coefficients

Absolute Rate Coefficients

Rate Coefficient (k) / Temperature / ReferenceTechniques and Comments
s-1Kelvin
(3.3 ± 0.2) × 10 -4 297Niki et al., 1985FTIR (a)
2.2 × 10 -4 298Senum et al., 1986FTIR (b)
2.52 × 10 16 exp(-13573/T)283–313Tuazon et al., 1991FTIR (c)
4.2 × 10 -4 298
(4.0 ± 0.8) × 10 16 exp(-13600)/T]300–330Bridier et al., 1991(d)
6.1 × 10 -4 298*
2.5 × 10 17 exp[-(14340 ± 250)/T]302–323Roberts and Bertman, 1992GC (e)
3.2 × 10 -4 298*
3.1 × 10 -4 298Roumelis and Glavas, 1992GC (f)
1.6 × 10 16 exp[-(13539 ± 1060)/T]288–298Grosjean et al., 1994GC (g)
3.0 × 10 -4 298

Comments

(a) Decay of CH 3 C(O)O 2 15 NO 2 in the presence of 14 NO 2 at a total pressure of 900 mbar of N 2 .

(b) Decay of CH 3 C(O)O 2 NO 2 (PAN) in the presence of NO at a total pressure of 16 mbar.

(c) Thermal decomposition of PAN in an environmental chamber in the presence of 970 mbar of synthetic air or N 2 .

(d) See comment (a) for k 0 .

(e) Thermal decomposition of PAN at 1 bar total pressure. PAN concentrations were measured by GC with electron capture detection.

(f) Thermal decomposition of PAN in N 2 as well as in the presence of O 2 , NO 2 and NO at 1 bar total pressure. The products methyl nitrate and NO 2 in PAN-N 2 mixtures were measured by GC. In the presence of large amounts of O 2 , no methyl nitrate was formed at 333 K, indicating that the decomposition of PAN to methyl nitrate and CO 2 does not occur. The data obtained were simulated with 23 reactions.

(g) Thermal decomposition of PAN in 1 bar of air. PAN was measured by GC with electron capture detection.

Preferred Values

ks-13.3-43.3×10-4  if   T 298   and   P 1 bar of air ks-1{3.8-43.8×10-4±0.3  if   T 298 5.416PlusMinus -13830300 T5.4×1016exp( -13830±300)/T  if   300 T 330

Comments on Preferred Values

The reported values from Bridier et al. (1991), Tuazon et al. (1991), Roberts and Bertman, (1992) and Roumelis and Glavas (1992) as well as the selected more recent measurements from Sehested et al. (1998) are all in very good agreement at 298 K and are preferred here. The direct PAN decompositions to methyl nitrate and CO 2 (Roumelis and Glavas, 1992; Orlando et al., 1992) or to CH 3 C(O)O and NO 3 (Orlando et al., 1992) are very slow compared to the decomposition to CH 3 C(O)O 2 +NO 2 .

References

  • Bridier, I., Caralp, F., Loirat, H., Lesclaux, R., Veyret, B., Becker, K. H., Reimer, A. and Zabel, F. , J. Phys. Chem. , 95 , 3594 , 1991.
  • Grosjean, D., Grosjean, E. and Williams II, E. L. , Air and Waste 44 , 391.1994.
  • Niki, H., Maker, P. D., Savage, C. M. and Breitenbach, L. P. , Int. J. Chem. Kinet. , 17 , 525 , 1985.
  • Orlando, J. J., Tyndall, G. S. and Calvert, J. G. , Atmos. Environ. , 26A , 3111 , 1992.
  • Roberts, J. M. and Bertman, S. B. , Int. J. Chem. Kinet. , 24 , 297 , 1992.
  • Roumelis, N. and Glavas, S. , Monatshefte f\"{u}r Chemie. , 123 , 63 , 1992.
  • Sehested, J., Christensen, L. K., Møgelberg, T., Nielsen, O. J., Wallington, T. J., Guschin, A., Orlando, J. J. and Tyndall, G. S. , J. Phys. Chem. A , 102 , 1779 , 1998.
  • Senum, G. I., Fajer, R. and Gaffney, J. S. , J. Phys. Chem. , 90 , 152 , 1986.
  • Tuazon, E. C., Carter, W. P. L. and Atkinson, R. , J. Phys. Chem. , 95 , 2434 , 1991.
  • Zabel, F. , Z. Phys. Chem. , 188 , 119 , 1995.