Dynamics of boron cluster ion reactions with deuterium: Adduct formation and decay

Abstract

Product cross sections for reaction of size-selected boron cluster ions with deuterium are reported for collision energies ranging from 0.05 to 10 eV. The major reactions are those in which one or two deuterium atoms add to the intact cluster. Other, higher energy channels involve fragmentation of the clusters, with and without addition of deuterium atoms. Cluster size dependent thresholds are observed for many reactions, and we have used these to estimate the cluster–D atom binding energy as a function of cluster size. Metastable adducts of the form BnD+2 are observed for reagent clusters as small as the tetramer. For small clusters, adducts form without activation energy, but starting at B+8 activation barriers are observed. Unimolecular decay rates of the adducts have been estimated, and the binding energy of D2 to various size cluster ions was extracted using RRKM modeling. Comparison is made with related results for boron surfaces and for aluminum cluster ions.