The gas-phase photolysis of cyclobutanecarbaldehyde

Abstract

The gas-phase photolysis of cyclobutanecarbaldehyde with λ 313 nm at 118° yields CO, cyclobutane, (E)-but-2-ene, ethylene, and traces of but-1-ene. CO, cyclobutane, (E)-but-2-ene, and but-1-ene are formed via initial α-cleavage. It is proposed that ethylene results from a molecular decomposition of vibrationally equilibrated, electronically excited cyclobutanecarbaldehyde. The photolysis is complicated by the thermal trimerization of the aldehyde. The α-cleavage and the fragmentation with formation of ethylene and propenal also occur under conditions of electron impact.