This research, and the consequent detection of the Criegee intermediate, was made possible by the advanced and unique equipment owned by the Combustion Research Facilities.
The instrument is a reaction chamber combined with a mass spectrometer. In this chamber, due to the operating conditions, the reaction takes place at a much slower pace; this allows the intermediate species to be detected.
Furthermore, with the mass spectrometer, it is possible to determine the weight and the molecular formula of all the species formed during the reaction. This means that it is possible to distinguish between different isomers – two species made with the same atoms, but with those atoms bonded together in different ways.
Reaction of CH2OO Criegee Intermediate
Further to the detection of the CH2OO intermediate, researchers also studied how this species reacted with other molecules, such as water (H2O), nitrogen monoxide (NO), nitrogen dioxide (NO2) and sulfur dioxide (SO2).
The results showed how the reactivity was very different, depending on the molecule involved. The reaction with H2O and NO, for instance, were slower than expected; for SO2 and NO2, on the contrary, the reaction rate was much higher.