Pd. Burrow et Dm. Pearl, DISSOCIATIVE ATTACHMENT FROM MONOCHLORINATED HYDROCARBONS IN THE GAS-PHASE, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 101(1-2), 1995, pp. 219-226
Gas phase measurements of the dissociative attachment (DA) process pro
vide fundamental data useful for the interpretation of studies incorpo
rating molecules on surfaces and in films. In this report, we review r
ecent DA studies in a series of monochlorohydrocarbons to examine the
role of the hydrocarbon framework, or ''substrate'', to which the Cl i
s attached. We find that the peak cross section decreases roughly expo
nentially as the vertical attachment energy to form the temporary nega
tive ion increases. We consider also the problem of measuring the smal
l cross section of methyl chloride and show that observation of the te
mperature dependence of the process provides information about the cro
ss section. We discuss briefly the recent theoretical studies of this
process in methyl chloride. Finally, we examine the effect of placing
a region of unsaturation, i.e., a double bond, in a location remote fr
om the C-CI bond and show that this enhances the DA cross section, pro
viding evidence for intramolecular transfer of the electron.