Norcorrole: Observation of the Smallest Porphyrin Variant with a N4 Core

A newborn member of the porphyrin family, the porphyrin(1.0.1.0) called norcorrole (shown in the center of the picture), was detected as an unexpected product of a spontaneous oxidative macrocyclization reaction of the iodidoiron(III) complex of 2,2′-bidipyrrin. It fills a gap in the family of contracted porphyrinoid variants and shows reactivity consistent with earlier DFT calculations.