UV absorption cross-sections of a series of dimethylbenzaldehydes.
The ultraviolet absorption cross-sections of 2,4-, 2,5-, 2,6-, 3,4- and 3,5- dimethylbenzaldehydes are reported in the wavelength range 240-320 nm. The measurements were carried out in the temperature range 318-363 K using two different experimental systems (D 2 lamp-monochromator and D 2 lamp-diode array). The absorption spectra of the five aldehydes have been found to exhibit relatively high absorption cross-sections in the region of the tropospheric interest with maxima around 290 nm. This work provides the first UV cross-section measurements for these aromatic aldehydes. The obtained cross-section values enable us to estimate the tropospheric photolysis lifetimes of these compounds. The results suggest that photolysis could be an important removal process for these species in the troposphere.
El Dib
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Equipe Astrochimie Expérimentale, Institut de Physique de Rennes, UMR 6251 du CNRS - Université de Rennes 1, Bat. 11c, Campus de Beaulieu, 35042 RENNES Cedex, France. gisele.eldib@univ-rennes1.fr
Chakir
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Mellouki
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D001272:Atmosphere; D001547:Benzaldehydes / Q000737:chemistry* / Q000528:radiation effects; D003903:Deuterium / Q000737:chemistry; D008027:Light; D010782:Photolysis; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013696:Temperature; D014466:Ultraviolet Rays
D001547:Benzaldehydes; D003903:Deuterium