Benzenoid and quinonoid nitrogen-containing heteropentacenes.

Benzenoid or quinonoid-that is the question? In connection with the debate on the structure of dihydro-5,7,12,14-tetraazapentacene, both benzenoid and quinonoid nitrogen-containing heteropentacenes were successfully isolated and investigated (see picture). This report presents an exploratory study of the molecular and electronic structures, molecular packing, and semiconductor properties of the two compounds. These findings may lead to useful implications for the interesting ladder polymers.