Photochemistry of anhydrides. Part 4.—Photolysis of perfluoro-n-butyric anhydride reaction of n-C3F7 radicals with cyclohexane

Abstract

The photolysis of the vapour of perfluoro-n-butyric anhydride was studied at 20 and 227°C. The effective primary process is (n-C₃F₇CO)₂O +hν→ 2 n-C₃F₇+ CO + CO₂ and the overall decomposition is quantitatively described by the equation (n-C₃F₇CO)₂O +hν→ n-C₆F₁₄+ CO + CO₂ The quantum yields of products increase with temperature but are independent of pressure. (n-C₃F₇CO)₂O was photolysed in the presence of cyclohexane vapour. For the reactions n-C₃F₇+ c-C₆H₁₂→ n-C₃F₇H + c-C₆H₁₁kH 2 n-C₃F₇→ C₆F₁₄kc we obtain, logkH/kc^½=(4.99 ± 0.12)–(23910 ± 750)/θ where θ= 2.303RTJ mol^–1 and k_H/k^½_c is in cm mol^–½ s^–½.