Ion–molecule reactions in the systems CF4–CH4 and CF4–C2H6

Abstract

Ion-molecule reaction mechanisms: Thermal energy gas phase reactions of 12C+ and 13C+ ions with CH4, C2H4, C2H6, C3H6, C3H8, and CD3CH2CD3 J. Chem. Phys. 65, 2574 (1976 10.1063/1.433444 Equilibrium studies of gas phase ion-molecule reactions. Ion cyclotron resonance results for the reaction CO2H+ + CH4 ? CH5 + + CO2A mass spectrometric study of ionic reactions in CH.-CF 4 and C,H 6 --CF 4 mixtures was undertaken at pressures as high as 0.52 torr. It was found that CFj ions react in a hydride transfer process with ethane with a rate constant of 3.3X 10-10 cm 3 molecule-I.s-I . A rate constant of 1.6X 10-10 cm' molecule -I·S -I was determined for the reaction of C,Ht ions with C,H 6 • In mixtures of CH. and CF 4 , both CHj and CHt react with CF 4 , apparently by fluoride ion transfer. for which we calculated rate constants of 8.6 X 10-10 and 2.3 X 10-10 cm' molecule-I·s-I • respectively. CFt ions do not attack molecular methane. There is good agreement with published rate constants for the disappearance of CHi. CHj. and CHt ions in pure methane. However we observed a decreasing CHi yield above 0.1 torr which may be due either to impurities or to excess energy in CHt ions as a result of a relatively high repeller field strength within the ion source in our experiments.

Gas‐phase chemistry of ionized and protonated GeF4: a joint experimental and theoretical study

“…Thus, under the conditions of FT mass spectrometry, SiF 3 + reacts with both methane and ethylene9 and undergoes three consecutive addition–HF elimination reactions to form (H 3 C)SiF 2 + , (H 3 C) 2 SiF + and Si(CH 3 ) 3 + from CH 4 and (H 3 C 2 )SiF 2 + , (H 3 C 2 ) 2 SiF + and Si(C 2 H 3 ) 3 + from C 2 H 4 . On the other hand, similar to GeF 3 + , CF 3 + is unreactive toward CH 4 57 and reacts with C 2 H 6 exclusively by hydride transfer 57. When reacted with C 2 H 4 at near thermal energies,58, 59 CF 3 + forms two major products, namely the addition–HF elimination product C 3 H 3 F 2 + obtained by a reaction strictly analogous to (12b) and the hydride transfer product C 2 H 3 + .…”

“…The gas‐phase reactions of CF 3 + and SiF 3 + with water,11, 15, 55 ammonia11, 16, 56 and hydrocarbons9, 57–62 were so far investigated by various mass spectrometric techniques. This invites a comparison with the corresponding reactions involving GeF 3 + .…”