In 1949, Criegee proposed that biradicals, or reactive molecules missing two chemical bonds, could form with the reaction of ozone and hydrocarbons (i.e. alkenes). Criegee presumed that these biradicals would play a substantial role in both removing pollutants from the lower atmosphere through oxidation and producing secondary organic aerosols. These secondary aerosols come from the reactions of atmospheric gases versus primary aerosols which come from such subtle sources as sea spray and wind-blown dust.

A short-lived molecule that forms naturally in the Earth’s atmosphere when ozone reacts with alkenes.

Researchers recently utilized a new method to create these Criegee intermediates in their lab. This big step enabled them to test these intermediates by combining them with several atmospheric compounds. Scientists found that the reactions with the pollutants produced aerosols. These aerosols are tiny particles that reflect solar radiation back into space! And it happens in a quicker manner than ever thought possible.

A German chemist born in 1902.

Received his doctorate at Wurzburg in 1925.

Died in 1972.