The photolysis of pentafluoroacetone

✍ Scribed by G. O. Pritchard; M. J. Perona

• Publisher: John Wiley and Sons
• Year: 1969
• Tongue: English
• Weight: 559 KB
• Volume: 1
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550010407

✦ Synopsis

The photolysis of pentafluoroacetone has been investigated in the 3130 A region, from room temperature to 360OC. The Qc0 varies from 0.7 to 0.9 over this range, and the decomposition is represented by CF,HCOCF, 4 CF,H + CO + CF,. The disproportionation/combination ratio for CF, and CF,H ( + CF,H + CF,) radicals is found to be 0.09. Arrhenius parameters for hydrogen atom abstraction from the ketone are log,, A = 12.7 (units are mole-l cc sec-1) and E = 14.3 kcal mole-' for CF,H, and log,, A = 12.1 and E = 11.8, for CF, radicals. At low pressures H F elimination reactions are observed from the vibrationally excited fluoroethanes, C,F,H* and C,F,H,*, formed in the system.

A rough estimate of the activation energy for the process C,F,H -+ C,F, + H F of 60-65 kcal mole-l is made.