Energetic bromine reactions in liquid aqueous solutions of methyl bromide

Reactions of 80Br activated by radiative neutron capture and 82Br activated by the reaction sup(82m)Br(IT)82Br were investigated in crystalline and liquid methyl bromide and liquid aqueous solutions of methyl bromide. In all systems the major labelled organic product was methyl bromide. For liquid aqueous systems, 80Br- and 82Br-labelled yields decreased with decreasing concentrations. Methyl bromide molecules tended to aggregate in the liquid aqueous system. The tendency for aggregation diminished as the solute concentration approached zero where the probable state of the solute approached a monomolecular dispersion. The 80Br- and 82Br-labelled methyl bromide yields extrapolated to 0.4+-0.1 and 1.4+-0.2%, respectively, at zero solute concentration. Within experimental error these extrapolated yields correspond to methyl bromide gas phase failure to bond rupture values. The data suggest that the sup(82m)Br(IT)82Br process results in energetic bromine species in the liquid state. The Auger effect Coulombic explosion model may have limited applicability to small molecules in the liquid state. (orig.)