The photolysis of trans-3,4-dimethylcyclopentanone. II. Short Wavelengths

The photolysis of trans-3,4-dimethylcyclopentanone has been investigated in the gas phase at 100°C using light of 206 and 193 nm. The photolytic products are propene, 1,2-dimethylcyclobutane, and the butene isomers. Small quantities of 3,4-dimethylpent-4-enal were also detected. Relative yields of these products were determined as a function of the ketone pressure and also of that of added nitrogen. A mechanism for the photochemical decomposition based on that suggested for the photolysis of cyclopentanone using short wavelength radiation, is consistent with the experimental results and is simpler than that required to account for the long wavelength photolysis reported earlier.