Porphyrin supermolecules: synthesis and self-assembly features of zinc-5-(3'-pyridyl)-10,15,20-tris(4'-hydroxyphenyl)porphyrin.

Targeted synthesis of the title compound, with one converging coordination site and three diverging H-bonding sites, has led to the formation of multiporphyrin oligomers by directed intermolecular coordination, without resorting to external auxiliaries. A uniquely structured cyclic tetraporphyrin supermolecule was detected in solution, isolated in the solid state, and characterized in detail by X-ray diffraction.