Our recent synthetic approaches to new porphyrinoids will be presented, which include extremely long linear molecules, extensively π-conjugated porphyrin tapes, cyclic porphyrin wheels, supramolecular but discrete porphyrin assemblies, new porphyrin systems that exhibits novel electronic properties such as stable anti-aromatic, monoradical, and biradical properties, expanded porphyrins, and contracted porphyrins (subporphyrins).
Another topic will be topology and aromaticity, in which our recent finding of many Möbius aromatic expanded porphyrins will be presented. For cyclic π-conjugated macrocycles with a single molecular twist, aromatic character will emerge for 4n conjugated π-electrons.