On radiation-chemical stability of polyhalogenoalkanes in condensed phase

Radiolysis mechanism of polyhalogen derivatives of hydrocarbons (CH2Cl2, CHCl3, CCl4) in a condensed phase, in particular, the reaction of dissociative electron addition (DEA), is investigated. On the basis of energy parameters of the systems considered, one may conclude that probability of DEA process is to fall in CH2Cl2, CHCl3, CCl4 series. The yield (G) of CH2Cl·, CHCl2·, CCl3· radicals under γ-radiation of methane halogen derivatives at 77 K is measured experimenally, by means of ESR method. The data obtained agree with the conclusion that probability of DEA process with participation of polyhalogen derivatives of hydrocarbon molecules and, thus, their relative radiation-chemical stability is determined by binding energy of carbon-halogen in molecular anion. In the case of solid phase, it is also necessary to take into consideration leveling influence of cell effect on G value. In liquid phase, where solvation of forming Cl-anion is possible, there is one more way for radical formation, which is connected with disociation of melecular ions