Formation and evolution of negative ion resonances in gas-phase and condensed-phase CHFCl2

The formation of negative ions following low-energy (0–14 eV) electron impact is studied for CHFCl2 molecules under different phase conditions. In the gas phase, the dominant dissociative attachment channel is Cl− appearing from a low-energy resonance at 0.5 eV whereas from the condensed phase one observes F− as the most abundant channel. In the Cl− desorption yield, the low-energy channel (at 0.5 eV) is completely suppressed in favour of effective desorption from a resonance near 8 eV. This behaviour is discussed in terms of the different energetics between gas-phase DA and anion desorption and the effect of the environment on the lifetime of resonances.