Spontaneous free radical/spin adduct formation and 1,3-dipolar molecular addition in reactions of cyanohalocarbons and C-phenyl N-tert-butyl nitrone (PBN)

Abstract

In this paper, the spin trap C-phenyl N-tert-butyl nitrone (PBN) is reported to react with cyanohalocarbons (CCl₃CN, CHCl₂CN, CHBr₂CN and CH₂BrCN) in a molecular reaction. Some 1:1 molecular adducts are produced in these reactions at room temperature in hexane via1,3-Bipolar cycloaddition. These addition compounds have been studied by GC–MS and MS–MS spectrometry.

At the same time, various free radicals are formed spontaneously from these systems. These radicals are detected by EPR spin trapping techniques and assigned as follows: carbon-centred radical (˙CH₂CN and ˙CHBrCN) spin adducts, nitrogen-centred radical (˙NCCCl₂, ˙NCCHCl and ˙NC–CHBr) spin adducts, oxygen-centred radical spin adducts and benzoyl-tert-butylaminoxyl.