Matrix isolation study of the photochemical reaction of cyclohexane, cyclohexene, and cyclopropane with ozone

The matrix isolation technique, combined with infrared spectroscopy, has been used to characterize the products of the photochemical reactions of cyclohexane, cyclohexene, and cyclopropane with ozone. While initial twin jet deposition of the reagents led to no visible changes in the recorded spectra, strong product bands were noted following irradiation with light of λ > 200 nm. Irradiation of matrices containing ozone and cyclohexane led to O atom reactions with insertion into a CH bond and a CC bond to form cyclohexanol and oxacycloheptane, respectively. Irradiation of matrices containing ozone and cyclohexene led to a mixture of products formed through oxidation of the double bond, including cyclohexanone and cyclohexene oxide. Cyclopropane and ozone were codeposited into argon matrices followed by irradiation, leading to the formation of both cyclopropanal through insertion into a CH bond and aldehydes through ring-opening and oxidation. These conclusions were supported by isotopic labeling (18O), by comparison to authentic infrared spectra, and by B3LYP/6-311G++(d,2p) density functional calculations.