Regional atmosphere ketones

As seen before, an inert atmosphere is a necessary condition during the conversion process in order to avoid the formation of carbonyl moieties through oxidation of the vinylene carbons [75, 105]. The ejqtosition of the precursor to otygen-rich atmosphere leads to the appearance of an IR absorption band in the region 1652-1772 cm, indicating the presence of the ketone group... 

Compounds that have a carbonyl moiety (group), C=0, on an end carbon (aldehydes) or middle carbon (ketones) are often the first species formed, other than unstable reaction intermediates, in the photochemical oxidation of atmospheric hydrocarbons. Aldehydes are important in atmospheric chemistry because they are second only to NO2 as atmospheric sources of free radicals produced by the absorption of light. This is because the carbonyl group is a chromophore, a molecular group that readily absorbs light and it absorbs well in the near-ultraviolet region of the spectrum to produce active species that can take part in atmospheric chemical processes. 

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