S+ and SF+ ions were found when the products of IR multiple-photon dissociation of SF6 molecules were irradiated by an intense pulse of UV radiation (lambda less than or equal to 243 nm). The performed experiments provided to conclude that the observed S+ and SF+ ions resulted from multiphoton UV dissociation of SF5 radicals with subsequent ionization of the products. The found effect was used for 'on-line' detection of unimolecular decay of SF6 in the molecular beam. The kinetics of dissociation of (SF6)-S-34 and (SF6)-S-32 IR MP excited by CO2 laser was measured. High primary selectivity of IR MPD of (SF6)-S-34 alpha(34/32) approximate to 80 was obtained for gas-dynamically cooled SF6 molecules.