The nucleophilic displacement (S(N)2) reaction F-+CH3Cl -> CH3F+Cl- induced by resonant electron capture in gas phase clusters

It is shown that the title nucleophilic displacement reaction can be observed in a crossed beam experiment where binary clusters composed of NF3 and CH3Cl interact with a monochromatized electron beam. The nucleophile, F- is generated within an energy region around 2 eV by resonant dissociative electron attachment (DA) from the NF3 component of the cluster and then undergoes an S(N)2 reaction with the substrate'' molecule CH3Cl. While low energy electron impact to CH3Cl gives no measurable Cl- signal due to the extremely low DA cross section (< 10(-22) cm(2)), we observe copious amounts of Cl- ions from the mixed cluster ions carrying the DA resonance profile of F-/NF3 which are hence identified as products of the corresponding S(N)2 reaction.