19252-52-9Relevant articles and documents
Ion-Molecule Reactions of Vibrationally State-Selected NO+ with Small Alkyl Halides
Wyttenbach, Thomas,Bowers, Michael T.
, p. 8920 - 8929 (2007/10/02)
The effects of vibrational excitation in NO+ (v=0-5) on its reactivity with small alkyl halides (CnH2n+1X; n=1-3; X=Cl, Br, I) have been investigated under thermal translational conditions.The method combines resonance enhanced multiphoton ionization to form state-selected NO+(v), and Fourier transform in cyclotron resonance techniques to trap, react, and detect ions.Besides vibrational quenching of NO+(v > 0), which is found to be very efficient with alkyl halides, three reaction channels are observed: charge transfer, halide transfer, and CnH2nNO+ formation.Branching ratios and rate constants have been determined for the different channels as a function of the NO+(v=0) vibrationally energy.Endoergic charge transfer is efficiently driven by vibrational excitation.Halide transfer is the major channel if it is significantly exothermic for NO+(v=0).If this is not the case, adding vibrational energy in NO+(v=0) is only marginally effective in driving this channel.The data suggest that rearrangements in NO+-alkyl halide reaction intermediates and in carbonium ions are very rapid.The CnH2nNO+ formation channel is only observed with n-propyl and isopropyl chloride where it is dominant for NO+(v=0).Increasing vibrational excitation inhibits C3H6NO+ formation.The results are discussed in terms of possible reaction mechanisms.
