Controlling molecular fragmentation using low energy electrons

Abstract

We show that functional group dependence exists in dissociative attachment of electrons to molecules and this leads to site and bond selectivity in fragmenting organic molecules at the N-H, O-H and C-H sites using electron energy as a control parameter. This phenomenon is investigated further by measuring the momentum distribution of hydride ions using the newly developed ion momentum imaging technique. We find that while the electron attachment at the O-site leads to a two-body fragmentation, attachment at the C-site leads to few-body fragmentation. Several new phenomena like 'bond orientation dependent electron attachment' and direct screening of one part of the molecule by another part to the incoming electron are unravelled in the very rich momentum distribution data of the hydride ions that we have obtained at various resonances.