La photolyse du cyclohexène gazeux à 184,9 nm

Abstract

We have studied the 184.9 nm photolysis of gaseous cyclohexene either in the absence or in the presence of radical scavengers such as O2, NO, H2S, or HI at pressures between 1 and 70 Torr. Propane or sulfur hexafluoride has also been used as stabilizing agent. In all cases, ethylene and 1,3-butadiene have rather high quantum yields (Ф ≥ 0.5). The isotopic analysis of the ethylene formed in the photolysis of cyclohexene-3,3,6,6-d4 shows the high importance of the perhydrogenated species. These results, together with others taken from the literature, favor a one-step fragmentation mechanism or a double-step mechanism involving an intermediate which has a lifetime shorter than that of the photoexcited molecule.