Criegee intermediate aldehydes, reaction with

Tetramethylethylene. Very recently, product studies on the 03 + tetramethylethylene (TME) reaction have been made by the authors group in attempts to probe various reaction channels operative for the dimethyl-substituted Criegee intermediate (CH3)2C—OO under atmospheric conditions [130]. Among the potentially important reaction channels suggested by previous theoretical studies [131] and experimental results in the gas- and solution-phases [122,132] are the bimolecular reaction with aldehydes (reaction (46c)) and the following unimolecular processes ... 

The Baeyer-Villiger oxidation is an oxygen insertion reaction whereby an aldehyde, cyclic or acyclic ketone 1 is treated with a suitable oxidant, e.g., an organic peracid 3, to form the corresponding formate, lactone or ester 2. The oxidation takes place in two discrete steps (1) the attack of the peroxide on the carbonyl to provide the Criegee intermediate, followed by (2) rearrangement to the product ester. 

The reaction of ozone and alkenes is sufficiently fast that it can compete with other removal processes and provide sinks for both ozone and alkenes in the troposphere. While kinetic data for a series of alkene/ozone reactions have been reported, not much is known about details of the reaction mechanisms, the role that carbonyl O oxides play, and the role that free radicals play in these processes. Our laboratory experiments provide the spectroscopic data (both infrared and UV/visible) that are important for the spectroscopic identification of Criegee intermediates in the troposphere. In addition, we were able to characterize secondary partially oxidized products (aldehydes, peroxides etc.) that are produced during the gas-phase ozonolysis. These products might lead to a net increase of ozone, if oxygen atoms are formed during their decomposition. 

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