Azulicorrole

Acid-catalyzed condensation of pyrrole, 4-trifluoromethylbenzaldehyde, and azulene, followed by DDQ oxidation, has resulted in the isolation of the novel macrocycle azulicorrole, arguably the first example of a carbacorrole aside from N-confused corrole. Despite poor yields (<1%), the free ligand could be structurally characterized and converted to the formal Cu­(III) and Au­(III) derivatives, of which the Cu­(III) complex could also be structurally characterized. Both the free base and the two metal complexes exhibit richly structured UV–vis spectra that extend well into the near-infrared, suggesting potential applications in bioimaging and photodynamic therapy.