Supramolecular organic frameworks (SOFs) of tetrakis(4-hydroxyphenyl)porphyrin with efficient guest inclusion

This study targets the construction of porphyrin-based supramolecular assemblies directed by hydrogen bonds, by utilizing the free-base tetratopic 5,10,15,20-tetra(4-hydroxyphenyl)porphyrin, and a series of N-containing monodentate and bidentate heterocycles (pyridine, 4,4′-bipyridine, 4,4′-bipyridylethene and phenazine) as building units. The component moieties contain attractive combinations of complementary molecular recognition functions for the formation of porphyrin only or porphyrin-N-heterocycle supramolecular organic frameworks (SOFs). Seven new crystalline materials could be synthesized and structurally characterized in this effort. Some of these supramolecular assemblies exhibit efficient inclusion of guests with a large aromatic backbone (pyrene and perylene). The optical properties of the available materials were also probed by solid state UV-vis diffuse reflectance spectroscopy (DRS).