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.