TECHNETIUM-CATALYSED OXIDATION OF HYDRAZINE BY NITRIC ACID.

Article abstract of DOI:10.1016/0022-5088(84)90023-7

Technetium catalyzes the oxidation of hydrazine by nitric acid, a reaction which is otherwise very slow except at elevated temperatures and acidities. The reaction displays an induction period followed by a rapid destruction of hydrazine. The induction period covers an initial slow reduction by hydrazine of technetium(VII) to technetium(IV) (the initiation phase) followed by a rapid technetium(IV)-catalyzed reduction of technetium(VII) by hydrazine (the induction phase). The fast reaction commences when technetium(VII) has been substantially reduced to technetium(IV). The mechanism of the fast reaction is considered to be the oxidation of technetium(IV) to technetium(VI) by nitrate, followed by reduction of technetium(VI) to technetium(IV) by hydrazine; nitrite produced in the oxidation of technetium(IV) reacts with another molecule of hydrazine to produce hydrazoic acid. On completion of the reaction, technetium is present predominantly as pertechnetate.