Photoionization detection of CF2 radicals resulting from the IR multiple-photon dissociation of CF2HCl molecules in a molecular beam

CF+ ions were detected when irradiating the CF2 radicals resulting from the IR multiple-photon dissociation (MPD) of jet-cooled CF2HCl molecules with an intense pulsed UV radiation (lambda less than or equal to 244 nm). The e xperiments performed allowed us to conclude that the CF+ ions observed were produced in the UV multiphoton excitation of the CF2 radicals via the reso nant intermediate state (A) over tilde B-1(1), followed by their fragmentat ion and ionization. This effect was used to study the unimolecular decay of CF2HCl under molecular beam conditions. We measured the kinetics of this p rocess, as well as the translational energies of the CF2 radicals. The isot opic selectivity of the IR MPD of (CF2HCl)-C-13 was found to improve substa ntially under jet-cooled molecular beam conditions. (C) 2001 Elsevier Scien ce B.V. All rights reserved.