Electron impact studies. CXXII. A comparison of reactivities and decompositions of benzoate anions and cations

Abstract

The benzoate anion reacts with acetic anhydride to yield an intermediate which decomposes by loss of ketene with accompanying proton transfer. The proton transfer is involved in the rate- determining step of the elimination reaction. The abundance of the product ion in the reaction of RC₆H₄CO₂^- with acetic anhydride increases as the electron-donating properties of R increase.    

Collision-induced charge stripping of the ions RC₆H₄CO₂^- yields the corresponding cations which fragment primarily by elimination of CO₂ (or O+CO). Fragmentation through the carboxyl centre precedes the fragmentation of R (e.g. when R = Me, MeO, Cl or Br).