Spectroscopic identification of jet-cooled p-fluoro-α-methylbenzyl radical in corona discharge

We report the first spectroscopic identification of the p-fluoro-alpha-methylbenzyl radical in the gas phase. Precursor p-fluoro-ethylbenzene seeded in a large amount of carrier gas was electrically discharged to produce the benzyl-type radicals in a corona excited supersonic expansion using a pinhole-type glass nozzle, from which the vibronic emission spectrum was recorded in the visible region. From an analysis of the spectrum observed, we identified spectroscopically the formation of the p-fluoro-alpha-methylbenzyl, in which the energy of the D-1 -> D-0 electronic transition and a few vibrational mode frequencies in the ground electronic state were determined by comparison with those from an ab initio calculation and with those from the known data of the precursor. (C) 2009 Elsevier B.V. All rights reserved.