Pollutant Hydrocarbons from the Anthrosphere

FIGURE 7.8 Structural formulas representative of classes of air pollutant hydrocarbons that may be introduced into the atmosphere from anthrospheric activities. 

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. 

Phenol Carboxylic acid (R is a hydrocarbon group such as CH3) 

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