Design and synthesis of porphyrins bearing rigid hydrogen bonding motifs: Highly versatile building blocks for self-assembly of polymers and discretearrays

Two aldehydes, 2,6-diacetamido-4-formylpyridine (7) and 1-butyl-6-formylura cil (11), are used to synthesize five pyridyl and four uracyl meso-subsitut ed porphyrins. With these complementary porphyrin building blocks, it is po ssible to build various types of multi-porphyrin supramolecules with differ ent spatial relationships in predefined geometries.,The formation and prope rties of self-complementary dimers and a closed tetrameric square are prese nted as a basis of comparison to the latter system in the solid state. An X -ray structure of 5,10-bis(4-tert-butylphenyl)-15,20-bis(3,5-diacetamido-4- pyridyl)porphyrin confirms its molecular structure and reveals a hydrogen-b onded supramolecular organization mediated by water molecules.