INTRACLUSTER ION-MOLECULE REACTIONS WITHIN CF3H CLUSTER SYSTEM

Ion/molecule reactions occurring within CF3H cluster ions are investig ated mass spectrometrically utilizing electron impact ionization. The study of fragmentation patterns indicates that the major reactive proc ess is the formation of protonated cluster ions via the ejection of CF 3 from the energized cluster ion. The parentages of major fragment ion s, e.g., (CF3H)nX+(X = CF2H and CF3, n greater-than-or-equal-to 1), ar e assigned from both pressure and electron energy dependence of these ions. The studies suggest that the precursors of (CF3H)nCF2H+ ions are the protonated CF3H clusters whereas the (CF3H)nCF3+ cluster ions are formed by a direct dissociative ionization of neutral (CF3H)q (q > n) clusters. The other fragment ions are produced by the consecutive eje ction reactions of neutral molecules (HF, H-2, and F2). Studies of the reactions within mixed CF3H/CH4 clusters also support the possible re active pathways for the formation of fragment ions.