ESR and Optical Studies of the Reaction Intermediates Produced from Phenyl Halides by Dissociative Electron Attachment in γ-Irradiated Organic Glasses at 77°K

ESR and optical studies have been made of dissociative electron attachment by phenyl halides and reaction intermediates produced in γ-irradiated glassy solid matrices at 77°K. Dissociative electron attachment by phenyl halides is an efficient process and the ratio of cross sections C6H5I/C6H5Br/C6H5Cl for this process in MTHF glass is 1.5/1.0/1.0. The phenyl radical produced abstracts a hydrogen atom from solvents (MTHF, 3MP) at 77°K and is stable in aqueous alkali-metal hydroxide glass. A part of 3MP radicals in a γ-irradiated solution of phenyl bromide in 3MP at 77°K disappear by a first-order process for which k=4.3×10−2 min−1. γ-Irradiated 3MP glasses containing phenyl halides exhibit the optical absorption spectra having characteristic absorption bands in the visible and UV region which are assigned to solute cations and hydrogen-adducts respectively.