| COMMENTS: | IUPAC(2006) recommendation: The preferred values of the cross-sections at 298 K over the range 185 nm to 230 nm are those obtained by M.P. Turberg, D.M. Giolando, C. Tilt, T. Soper, S. Mason, M. Davies, P. Klingensmith, and G.A. Takacs, "Atmospheric chemistry of alkyl nitrates," J. Photochem. Photobiol. A. Chem. 51, 281-292 (1990); DOI: 10.1016/1010-6030(90)87063-H, and for the range 235 nm to 340 nm averages are taken of the values from all of the five studies at the wavelengths where they overlap, J.M. Roberts and R.W. Fajer, "UV absorption cross sections of organic nitrates of potential atmospheric importance and estimation of atmospheric lifetimes," Environ. Sci. Technol. 23, 945-951 (1989); DOI: 10.1021/es00066a003, M.P. Turberg, D.M. Giolando, C. Tilt, T. Soper, S. Mason, M. Davies, P. Klingensmith, and G.A. Takacs, "Atmospheric chemistry of alkyl nitrates," J. Photochem. Photobiol. A. Chem. 51, 281-292 (1990); DOI: 10.1016/1010-6030(90)87063-H, L. Zhu and C.-F. Ding, "Temperature dependence of the near UV absorption spectra and photolysis products of ethyl nitrate," Chem. Phys. Lett. 265, 177-184 (1997); DOI: 10.1016/S0009-2614(96)01404-2, K.C. Clemitshaw, J. Williams, O.V. Rattigan, D.E. Shallcross, K.S. Law, and R.A. Cox, "Gas-phase ultraviolet absorption cross-sections and atmospheric lifetimes of several C2-C5 alkyl nitrates," J. Photochem. Photobiol. A: Chem. 102, 117-126 (1996); DOI: 10.1016/S1010-6030(96)04458-9, and R.K. Talukdar, J.B. Burkholder, M. Hunter, M.K. Gilles, J.M. Roberts, and A.R. Ravishankara, "Atmospheric fate of several alkyl nitrates. Part 2. UV absorption cross-sections and photodissociation quantum yields," J. Chem. Soc. Faraday Trans. 93, 2797-2805 (1997); DOI: 10.1039/A701781B The temperature variation of the absorption cross-section at a particular wavelength in the range 240 nm to 340 nm is expressed as ln σ(T) - ln σ(298 K) = B × (T-298) with the temperature coefficients, obtained by averaging the data of Zhu and Ding (1977), Clemitshaw et al. (1996), and Talukdar et al. (1997): ---------------------
λ 103 B
(nm) (K-1)
----------------------
235 1.4
240 2.8
245 2.9
250 2.8
255 2.6
260 2.6
265 2.9
270 3.1
275 3.3
280 3.6
285 3.8
290 4.2
295 4.7
300 5.1
305 5.8
310 6.7
315 7.9
320 8.6
325 10.4
330 12.9
335 14.1
340 15.6 |
