Infrared multiphoton dissociation of two perfluorobutenes

Abstract

Advances in site-specific dissociation of molecules using synchrotron radiation AIP Conf. Proc. 475, 622 (1999) Photofragment translational spectroscopy was used to examine the infrared multiphoton dissociation of octafluoro-1-butene and octafluoro-2-butene. The predominant unimolecular reaction in octafluoro-1-butene at moderate laser fluences is cleavage of a carbon-carbon single bond to give the products CF 3 and C 3 F 5 . The two other reactions that take place are CF 2 elimination and the formation of equal weight fragments with the chemical composition C 2 F 4 ; both reactions take place via a diradical intermediate. Dissociation of octafluoro-1-butene to the resonance stabilized perfluoroallyl radical is suggested to account for the favoring of simple bond rupture. These three reaction pathways were also observed in octafluoro-2-butene dissociation, however, the branching fraction is different than from octafluoro-1-butene. In octafluoro-2-butene all three channels occur with roughly equal probability. The reactions involving CF 2 loss and C 2 F 4 formation in octafluoro-2-butene are thought to proceed through the same diradical intermediate as in octafluoro-1-butene, necessitating a 1,2-fluorine migration.

Kinetics and Mechanism of the Sonolytic Conversion of the Aqueous Perfluorinated Surfactants, Perfluorooctanoate (PFOA), and Perfluorooctane Sulfonate (PFOS) into Inorganic Products

“…The pyrolytic kinetics of the experimental technique is listed in parentheses for 1H-perfluoropropane (IRMPD), 1-perfluorobutene (IRMPD), perfluorohexane (VLPP), and their decomposition intermediates are listed in Table . First-order rate constants and half-lives are estimated using a temperature of 2500 K, which is less than the average vapor temperature achieved during a single transient cavitation event ,,, in water.…”