Vacuum pyrolysis of perfluorohexadiene-1,5: Matrix IR spectrum of the free perfluoroallyl radical

Abstract

1. Mass spectrometry and matrix IR spectroscopy have been used to identify the primary products of the vacuum pyrolysis of perfluorohexadiene-1,5, including the unstable particles CF2 and CF3, and the free perfluoroallyl radical C3F5 which is the main pyrolysis product at pyrolysis temperatures of 750–980°. 2. The conversion paths of free radicals C3F5 and CF3, stabilized in an Ar matrix, have been established when warming the matrix to 35–40 K, as well as the decomposition route of the radical C3F5 in the gas phase above 850° with the formation of CF2=C=CF32 or CF3C≡CF. 3. The most intensive bands in the IR spectrum of the perfluoroallyl radical have been determined for the first time, including the band at 1498 cm−1 which has been assigned to vas CCC vibration; it characterizes the relatively low strength of the bonds of the Π-allyl system.