Mechanistic investigation of SN2 dominated gas phase alkyl iodide reactions

  • Garver J
  • Eyet N
  • Villano S
 et al. 
  • 3


    Mendeley users who have this article in their library.
  • 7


    Citations of this article.


The competition between substitution (SN2) and elimination (E2) has been studied for the reactions of methyl, ethyl, isopropyl, and tert-butyl iodide with Cl-, CN-, and HS-in the gas phase. Previous studies have shown a dominance of the SN2 mechanism for sulfur anions and for some cyanide-alkyl iodide reactions. Although our results support this conclusion for the reactions studied, they reveal that competition between the SN2 and E2 pathways exists for the isopropyl reactions. Steric and electronic effects, upon alkyl group substitution, produce looser and less stable SN2 transition states, however, they can favor the E2 process. These opposing effects on barrier heights produce E2/SN2 competition as steric hindrance increases around the α-carbon, however the relative differences in intrinsic barrier heights lead to significantly different branching ratios. This interpretation is discussed in terms of reaction efficiencies, kinetic isotope effects, linear basicity-reactivity relationships, electrostatic models, and transition state looseness parameters.

Author-supplied keywords

  • Barrier height
  • Gas phase
  • Ion/molecule
  • Mechanism
  • Reactivity
  • Transition state

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • John M. Garver

  • Nicole Eyet

  • Stephanie M. Villano

  • Zhibo Yang

  • Veronica M. Bierbaum

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free