REACTIONS OF ETHYL, PROPYL, AND BUTYL CATIONS WITH METHYLSILANE AND ETHYLSILANES

The gas-phase reactions of C2H5+, iec-C3H7+, and t-C4H9+ with (CH3)nSiH4-n-, and of C2H5+ with (C2H5)n-SiH4-n(n = 0,1,2,3,4) have been studied in a tandem mass-spectrometric apparatus. Reaction cross sections at 1 eV kinetic energy in the laboratory system have been determined for the reaction of C2H5+ ions by comparison with the known cross section for hydride ion transfer from SiH4 to CH3+. The predominant processes are H- and CH3- (or C2H5-) transfer from the silane to the attacking ion, with the alkyl anion transfer becoming dominant when the number of CH3 groups in the silane is three or four. The reaction energetics show that CH3- and C2H5- transfer occurs as a process involving the simple interchange of the molecular anion between reactants. © 1979, American Chemical Society. All rights reserved.