Reactivity of bromine atom complexes with organic compounds

Abstract

Complexes of bromine atoms with bromo compounds (C{sub 2}H{sub 5}Br{center dot}Br, CH{sub 2}Br{sub 2}{center dot}Br, CHBr{sub 3}{center dot}Br, and CBr{sub 4}{center dot}Br) were produced by pulse radiolysis of the corresponding bromoalkane dissolved in cyclohexane. With benzene as solvent, the complex C{sub 6}H{sub 6}{center dot}Br was produced. These complexes oxidized phenols to phenoxyl radicals and abstract reactive hydrogens from various compounds. Absolute rate constants for these reactions were determined by following the decay of the Br atom complexes (at 370, 390, 425, 480 and 540 nm, respectively) as a function of substrate concentration. The rate constants varied from 10{sup 5} to 10{sup 10} M{sup {minus}1} s{sup {minus}1} and were strongly dependent on the nature of the Br atom complex and of the organic substrate.