New assembly modes of porphyrin-based networks

The meso-5-pyridyl-10,15,20-tri(hydroxyphenyl)porphyrin has been synthesized and reacted with 1,2-dichloroethane to yield the corresponding pyridinium chloride salt with N_py-alkylated porphyrin building block. The latter undergoes self-assembly to form flat-networked patterns sustained by chloride anion auxiliaries, which attract cooperative hydrogen bonding from the hydroxylic functions of adjacent species. The O-H⋯Cl- attractions direct the structure of the multiporphyrin arrays, thus representing a useful synthon for the construction of extended porphyrin-based architectures. Tight stacking of the hydrogen-bonded polymeric layers in the axial direction is further stabilized by ion-pairing interactions.