MOLECULAR STRUCTURE AND PHOTOCHEMICAL REACTIVITY .12. VAPOR-PHASE PHOTOCHEMISTRY OF ACROLEIN AT 3130 A

The vapor-phase photochemistry of acrolein has been studied at 3130 Å between 35 and 200˚. The major photodecomposition products were CO (Φ~5×10−3) and C2H4 (Φ ~ 3 × 10−3). C2H2andC4H6 (butadiene) were minor products (Φ < 10−6)> and small amounts of CO2 were formed in a bimolecular dark reaction. These results, and those of previous workers, are explained by a mechanism involving the primary steps for decomposition of excited acrolein: CH2=CHCHO*⇅C2H3 + HCO and CH2=CHCHO*⇅C2H4 + CO. The relative importance of the two processes varies with the pressure of the irradiated gas. © 1969, American Chemical Society. All rights reserved.