Knowledge Bank

The mechanistic sequence and kinetics of the reaction of ozone with olefins have been investigated by numerous spectroscopic techniques including several microwave $studies.1$ The majority of the previous experimental results supports the ozonolysis mechanism proposed by Criegee:$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ [FIGURE] Although considerable effort has been invested in experimental studies of ozonolysis of olefins, to date neither the primary $ozonide1$ nor the $intermediate2$ have been identified in the ethylene-ozone reaction. We report the identification of stable measurements have been carried out over the range of 18-130 Ghz in a cooled septum abosrption cell. Preliminary analysis of the spectrum provides convincing evidence that the dioxymethane intermediate observed has the stable ring structure (figure), rather than the biradical or zwitterion form, with k=+ 0.447 and $\mu _{b} =2.7 \pm 0.2 \ $D. The final results for this species and several isotopic forms will be presented.