Abstract
A derivative of the new heterocyclic system cyclobuta[4,5]pyrrolo[1,2-a][1,10]phenanthroline was obtained by condensation between 2,9-dimethyl-1,10-phenanthroline and dimethyl acetylenedicarboxylate, and its structure was assigned by X-ray analysis. The strained molecular conformation observed for this pentaheterocyclic framework can be attributed to a series of repulsive intramolecular interactions that render both the phenanthroline system and the four-membered ring non-planar.
