Acetic anhydride mediates a facile and rapid condensation of benzimidazole with aromatic o- diacid dichlorides to precipitate p-dione adducts in excellent yields. Condensation with pyridine-3, 4-dicarbonyl dichloride produced a 1: 1 mixture of isomeric p-diones. The X-ray crystal structure of one of the latter isomers revealed unusual high density, and inter-layer separation similar to graphite. Cyclic voltammetry demonstrated that p-dione is capable of ...