Radiation mechanisms. Part 4.—Electron spin resonance studies of γ-irradiated trichloronitrosomethane and trichloronitromethane

Abstract

Trichloronitromethane on exposure to ⁶⁰Co γ-rays at 77 K gives NO₂ radicals by dissociative electron capture. However, in methanol glasses, NO₂ is barely detectable, the predominating radical formed by electron capture being ·CCl₃. The hole centre formed by this molecule is thought to be CCl₃NO⁺₂ with the unpaired electron largely confined to oxygen.

In contrast, trichloronitrosomethane gives no ·CCl₃ radicals under any conditions, the major electron capture radical being probably NO. The e.s.r. spectrum for the hole centre for this compound is characteristic of iminoxy radicals and is therefore thought to be the cation Cl₃C—NO⁺.