Syntheses of polypyrrolic macrocycles

Pentaphyrins are pentapyrrolic macrocycles containing five bridging methine groups between the five pyrrolic subunits. The syntheses of decamethylpentaphyrin 71, 2-ethoxycarbonyl-3,7,8,12,13,17,18,22,23-nonamethylpentaphyrin 74, 2-ethoxycarbonyl-3,7,8,22,23-pentamethyl-12,13,17,18-tetraethylpentaphyrin 75, 3,12-dimethoxycarbonylethyl-2,7,8,-13,17,18,22,23-octamethylpentaphyrins 29 and the zinc complexes of 71 and 74 are described. The physical properties of the pentaphyrins show them to be aromatic like sapphyrins, porphyrins and corroles. This aromaticity is reflected in the large shielding of the NH protons and the deshielding of the methine protons in the nmr spectra and by their optical spectra, which exhibit Soret and visible bands similar to sapphyrins and porphyrins.Science, Faculty ofChemistry, Department ofGraduat