Absorption cross-sections formaldehyde

Rogers, J. D., Ultraviolet Absorption Cross Sections and Atmospheric Photodissociation Rate Constants of Formaldehyde, J. Phys. Chem., 94, 4011-4015 (1990). 

The absorption cross section of formaldehyde (Figure 4.42) has been studied by several investigators since the experiments of Henri and Schou (1928), in particular by Bass et al. (1980), Moortgat et al. (1980 1983), and Cantrell et al. (1990). It has long been recognized (Herzberg, 1931 Norrish and Kirkbride, 1932) that the photolysis of CH2O can lead to two different product paths ... 

Formaldehyde photolysis is a significant source of free radicals in the troposphere. Absorption cross sections for HCHO are given by DeMore et al. (1994). DeMore et al. (1994) give quantum yields, i and [Pg.145]

Formaldehyde photolyzes by reactions 5.32a and 5.32b and reacts with OH by reaction 5.33. Recommended absorption cross sections and quantum yields are cited in Table 3.3. Acetaldehyde photolyzes by (Table 3.3)... 

Absorption cross-sections of formaldehyde was obtained in the range 240-360 nm at 298 and 220 K by diode array spectroscopy with a spectral resolution of 0.022 nm (Moortgat). These values are consistently higher (up to 10 %) than those previously measured. 

Pope, F.D., Smith, C.A., Ashfold, M.N.R., Orr-Ewing, A.J. High-resolution absorption cross sections of formaldehyde at wavelengths from 313 to 320 nm. Phys. Chem. Chem. Phys. 7, 79-84 (2005a)... 

Rogers, J.D. Ultraviolet absorption cross sections and atmospheric photodissociation rate constants of formaldehyde. J. Phys. Chem. 94, 4011 015 (1990)... 

Meller, R., and G.K. Moortgat (2000), Temperature dependence of the absorption cross-sections of formaldehyde between 223-323 K in the wavelength range 225-375 nm, J. Geophys. Res., 105, 7089-7101. 

Figure IX-G-1. Comparison of the wavelength dependence of the cross sections of some halogen-atom-substituted formaldehyde molecules and the actinic flux as measured for a cloudless day (June 19, 1998) near Boulder, CO at noon, (a) Shows the spectra for the formyl halides (b) gives the spectra for the carbonyl halides. Note that only the HC(0)Br and BrC(0)Br compounds have a significant overlap with the available actinic flux in the lower troposphere with an overhead Sun (gray curve). The long wavelength tail of the absorption of HC(0)C1 and C1C(0)C1 molecules catches the edge of the flux distribution. Spectral data from Keller-Rudek and Moortgat (2005) figures from Calvert et al. (2008).

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