Abstract
The half-wave potentials of five homologous o-quinones shown below were measured under identical conditions by the nonaqueous polarography in glacial acetic acid containing 0.25N ammonium acetate : 1, 2-Naphthoquinone (o-NQ), 1, 2-anthraquinone (o-AQ), 9, 10-phenanthrenequinone (Ph. Q), benz [a] anthra-5, 6-quinone (o-BAQ), dibenz-[a, h] anthra-5, 6-quinone (o-DBAQ). The order of the ease with which they are reduced at the dropping mercury electrode are given by the following sequence : o-NQ > o-AQ > Ph.Q > o-DBAQ > o-BAQ This order agreed with the resonance theory as in the case of p-quinones described in a previous paper. From the standpoint of the order of E1/2's of the above-mentioned o-quinones, it was found that they might play some important roles in the carcinogenesis of their parent hydrocarbons.
