Surface-aligned ion-molecule reaction on the surface of a molecular crystal CD(sub 3)(super +) + CD3l yields C2D(sub 5)(super +) + Dl

An ion-molecule reaction is observed from a condensed molecular crystal of CD3l using the time-of-flight electron-simulated desorption ion angular distribution technique. The findings show that the yield and directionality of the emission of the C2D5+ product ion is governed by the molecular order that is the characteristic of the molecular crystal of CD3l.