Gamma Radiolysis of Aqueous Solutions of Aryl Alkyl Amines

Irradiation of benzyltrimethylammonium ions in aqueous solution results in deamination brought about by hydrated electrons. Trimethylamine is the major nitrogenous deamination product. The rate constant for the reaction with electrons, established by competition kinetics, is <tex-math>$k_{a}=(0.95\pm 0.27)\times 10^{10}\ \text{liter mole}^{-1}\ {\rm sec}^{-1}$</tex-math>. In concentrated solution (<latex>$>10^{-2}\ M$</latex>), <tex-math>$G({\rm Me}_{3}{\rm N})$</tex-math> is significantly higher than <tex-math>$G_{{\rm e}_{{\rm aq}}^{-}}$</tex-math>. Radiation-induced deamination of benzyldimethylamine is also observed. Reductions in yield of dimethylamine, the deamination product, are brought about by the addition of electron scavengers, but the magnitudes of these reductions are not in accord with simple competition kinetics.