Matrix isolation study of the early intermediates in the ozonolysis of cyclopentene and cyclopentadiene: observation of two Criegee intermediates.

Matrix isolation studies, combined with infrared spectroscopy, of the twin jet codeposition of ozone into matrices containing either cyclopentadiene or cyclopentene have led to the first observation of several early intermediates in these ozonolysis reactions. Specifically, evidence is presented for the formation, identification, and characterization of the long sought-after Criegee intermediate for each system, as well as the primary and secondary ozonides. These were observed after initial twin jet deposition and grew approximately 300% upon annealing to 35 K.

Matrix isolation studies of photochemical and thermal reactions of 3- and 5-membered cyclic hydrocarbons with CrCl2O2.

The matrix isolation technique has been combined with infrared spectroscopy and theoretical calculations to characterize the products of the photochemical and thermal reactions of cyclopentadiene, cyclopentene, cyclopentane, and cyclopropane with CrCl 2O 2. While initial twin jet deposition of the reagents led to no visible changes in the recorded spectra, product bands were observed following irradiation with light of lambda > 300 nm. The irradiation was shown to lead to oxygen atom transfer to the five-membered rings, forming complexes between cyclic alcohol derivatives and CrCl 2O.

Matrix isolation investigation of the photochemical reaction of benzene with CrCl2O2 and OVCl3.

The matrix isolation technique, combined with infrared spectroscopy, has been used to characterize the products of the photochemical reactions of benzene with CrCl(2)O(2) and OVCl(3). 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 lambda > 300 nm. Wavelength dependence studies determined that light of lambda < 590 nm led to reaction and oxygen atom transfer, forming an eta(1)-complex between 2,4-cyclohexadienone and CrCl(2)O.

Matrix isolation investigation of the photochemical reaction of methyl-substituted benzenes with CrCl2O2.

The matrix isolation technique, combined with infrared spectroscopy, has been used to characterize the products of the photochemical reactions of toluene, m-, o-, and p-xylene, mesitylene, and hexamethylbenzene with CrCl2O2. 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 lambda > 300 nm. The irradiation was shown to lead to oxygen atom transfer, forming complexes between methylcyclohexadienone derivatives and CrCl2O.