THE ULTRAVIOLET PHOTOCHEMISTRY OF CONDENSED-PHASE ACETYL-CHLORIDE

Ultraviolet (UV) irradiation of amorphous and crystalline samples of s olid acetyl chloride produces metastable HCl . ketene complexes in a 1 :1 ratio following S-1 photoexcitation, The HCl . ketene complex is th e only product observed following UV irradiation of either amorphous o r crystalline samples, The condensed-phase reaction mechanism contrast s starkly with that of the gas phase mechanism that produces Cl and CH 3CO radicals by prompt photolysis, followed by dissociation of interna lly excited CH3CO to form CO and CH3 in a non-concerted process.