Electron capture negative ion mass spectra of some freon derivatives

The temperature dependence of dissociative attachment has been investigated in the temperature range 350-575 K for two freon derivatives 1,1,1-C2H3F2Cl and C2F5Cl using Electron Capture Negative Ion Mass Spectra (ECNI MS). The temperature dependence for 1,1,1-C2H3F2Cl is similar to that observed in the case of CF3Cl reported by Illenberger et al. In contrast, C2F5Cl exhibits quite a different spectrum and its temperature behavior. It has been suggested that sigma*C-Cl delocalization onto two empty orbital leads to Cl- ion formation in two different resonance states.