Pyrrole Also aromatic,but lone pair of electrons is delocalized,so much weaker base. Lone pair in p orbital Lone pair Pyrrole (Six m electrons】 (p) H+H,O→ OH pyrrole.pK=13.6 N-protonated pyrrole.pk =0.4 (weak base) (strong acid) OH pyrrole N-protonated pyrrole (aromatic) (nonaromatic)Pyrrole Also aromatic, but lone pair of electrons is delocalized, so much weaker base