Photochemistry of Long-Lived [(CF_3)_2CF]_2C~·C_2F_5 Radicals in a Hexafluoropropylene Trimer Matrix

摘要

The kinetics of photodecomposition of long-lived [(CF_3)_2CF]_2C~·C_2F_5 radicals (I) in glassy and liquid hexafluoropropylene trimer was studied at 77 and 300 K, respectively. It was found that the phase state of the hexafluoropropylene trimer matrix did not affect the photodecomposition mechanism. In both cases, I eliminates ~·CF_3 radical from the perfluoroethyl fragment. The molar absorption coefficient of I was determined: ε_(250) = 49 m~2 mol~(-1). It was shown that the photodecomposition of I in a liquid matrix at 300 K led to the formation of other long-lived radicals. One of these species is [(CF_3)_2CF]_3C~· radical, which results from addition of ~·CF_3 radical to the double bond of a hexafluoropropylene trimer molecule.