ION CHEMISTRY IN TRIFLUOROMETHANE, CHF3

Cross sections for dissociative ionization of trifluoromethane by elec tron impact have been measured using Fourier-transform mass spectromet ry. Four fragment ions, CHF2+, CF3+, CF2+, and CF+ are observed, with a total cross section of 3.4 +/- 0.4 x 10(-16) cm(2) at 60 eV. CFx+ (x = 1 - 3) ions react with neutral CHF3 to yield CHF2+ with rate coeffi cients of 3.9 +/- 0.5 and 2.1 +/- 0.4 x 10(-10) cm(3)s(-1) for x = 2 a nd 3, respectively. The rate of cationic polymerization is less than 7 x 10(-13) cm(3)s(-1) and the anions F- and CF3- have yields less than 3 x 10(-20) cm(2) between 30 and 60 eV. (C) 1997 Published by Elsevie r Science B.V.