Collect. Czech. Chem. Commun. 1983, 48, 203-214

Photolytic and thermal annealing of radical anions in gamma-irradiated ammonium salts of carboxylic acids

Karel Macha and Karel Vacekb

a J. Heyrovský Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, 121 38 Prague 2
b Department of Radiation Chemistry, Institute of Nuclear Research, 250 68 Řež


The γ-radiolysis of simple ammonium carboxylates at 77 K generates radical anions in yields comparable with those found in parent carboxylic acids. The structure of radical anions as derived from their ESR spectra and their behaviour on thermal annealing and photobleaching is mostly analogous to that found in carboxylic acids. The fast photobleaching of radical anions allowed to estimate the amount of radical anions in the sum of all paramagnetic products after γ-radiolysis. These amounts ranged usually 50% only in ammonium acetate the unexplainable 75% of radical anions were found. Very efficient photolytic and thermal transformations of radicals RCHCOO ⇄ RCH2 were observed in ammonium acetate (R = H) while in the propionate (R = CH3) both radicals decayed during photolysis.