The stability of [CCl 4] +·, [Cl 2CClCl] +·, their dications, and neutral counterparts

Abstract

Electron impact ionization of tetrachloromethane has been shown to produce stable [CCl 4] +· ions; their heat of formation is ⩽ 237 kcal mol −1. The ylid isomer, [Cl 2CClCl] +·, generated upon dissociative ionization of Cl 3CCOCl, is remarkably more stable; Δ H 0 f([Cl 2CClCl] +·) < 224 kcal mol −1. The values for both isomers are significantly lower than calculated values. The corresponding neutrals, CCl 4 and Cl 2CClCl, are not stable on the time and energy scale of neutralization—re-ionization experiments. Although [Cl 2CClCl] 2+, was calculated to be stable, it was not present in the charge-stripping mass spectrum of the ylid ion.