EPR and mass spectroscopic identification of radical adducts produced spontaneously from reactions of phosgene, chlorine gas and bromine with C-phenyl N-tert-butyl nitrone (PBN)

The toxic gas phosgene reacts with the spin trap C-phenyl N-tert-butyl nitrone double dagger (PBN) to produce spontaneously N-tert-butyl-N-chloroacylaminoxyl as the main radical product identified by EPR and mass spectrometry, The reaction mechanisms for the formation of N-tert-butyl-N-chloroacylaminoxyl and other radicals are proposed. Reactions of chlorine gas and bromine with PEN have also been investigated. First alpha-chloro- or alpha-bromo-PBN is formed followed by chlorination or bromination of the aryl ring of these compounds, respectively.