Corrole

A corrole is an aromatic organic chemical, whose structure is in the form of the corrin ring which the same used in vitamin B12. The ring consists of nineteen carbon atoms, with four nitrogen atoms in the core of the molecule.

Corrole normally serves as a trianionic ligand with transition metals.

Corroles can be obtained in organic synthesis by a condensation reaction of a benzaldehyde with pyrrole in a water / methanol / hydrochloric acid mixture to an open-ring bilane or tetrapyrrane followed by oxidation and ring closure with p-chloranil :