A rare and unusual class of tripyrrolic compounds, violet-colored tripyrrin-1, 14-diones, can be prepared easily and in moderately high yields from base (piperidine)-catalyzed condensation of 3-pyrrolin-2-ones with 2, 5-diformylpyrroles. Dipyrrinones adopt the all-syn- Z conformation leading to helical, lock-washer like structures, which form dimers that are held together by intermolecular hydrogen bonds in nonpolar solvents and in the crystal. ...