Phthalocyanines are structurally related to other tetrapyrrole macrocyles including porphyrins and porphyrazines.
They feature four pyrrole-like subunits linked to form a 16-membered inner ring composed of alternating carbon and nitrogen atoms.
 Structurally larger analogues include naphthalocyanines.
The pyrrole-like rings within H
₂Pc are closely related to isoindole.
Both porphyrins and phthalocyanines function as planar tetradentate dianionic ligands that bind metals through four inwardly projecting nitrogen centers.
Such complexes are formally derivatives of Pc²⁻
, the conjugate base of H
₂Pc.
Phthalocyanines are structurally related to other tetrapyrrole macrocyles including porphyrins and porphyrazines. They feature four pyrrole-like subunits linked to form a 16-membered inner ring composed of alternating carbon and nitrogen atoms.  Structurally larger analogues include naphthalocyanines. The pyrrole-like rings within H
₂Pc are closely related to isoindole. Both porphyrins and phthalocyanines function as planar tetradentate dianionic ligands that bind metals through four inwardly projecting nitrogen centers. Such complexes are formally derivatives of Pc²⁻
, the conjugate base of H
₂Pc.
Phthalocyanine