Isotope effect in transfer of hydrogen atom from matrix molecules to carboxymethyl radicals in crystalline potassium hydromalonate

By the ESR method kinetics of hydrogen and deuterium detachment by carboxymethyl radicals from the matrix molecules in potassium hydromalonate subjected to γ-radiation at 77 K and in its deuterium-substituted analog is studied. It is shown that kinetics isn't described by the exponential law, that activation energy of hydrogen atom detachment is ∼ 45 kJ/mol, that the substitution of atom D for transferred atom H decreases the reaction rate ∼ 2 times at 225 K. The supposition is made that atom transfer is not a limiting stage