Abstract
Polarographic reduction processes of Girard hydrazones of aliphatic and aromatic ketones were studied. From the results of controlled potential electrolysis, the two-electron reduction process proposed by Prelog and Hafliger for Girard-T Hydrazones of aliphatic and alicyclic ketones was found to be not correct, and a mechanism shown in scheme (4) containing a four-electron reduction process was proposed instead. In the case of the Girard hydrazones of aromatic ketones, the electrode reaction processes seem to be more complicated than the aliphatic series : A reduction mechanism shown as scheme (6) containing four and two-electron reduction processes has been proposed. These mechanisms can explain the polarographic behaviours of Girard hydrazones most adequately. In connection with this study, ultraviolet absorption spectra of Girard hydrazones were measured under various conditions. The molecular forms of Girard hydrazones under the experimental conditions have been discussed from the results.
