Conformation and Aromaticity of Porphyrinoids

Stępień, M.; Sprutta, N.; Latos-Grażyński, L.
Angew. Chem. Int. Ed. 2011, 50, 4288-4340 | view at publisher's site

Incredibly elastic, superbly π-conjugated—and how colorful! Playing with porphyrinoids can be a grand pastime for any aromaticity-loving chemist. This exciting building set now contains not only pyrroles and methine bridges but also a variety of other hetero- and carbocycles. Snap a few π-bonds in place and you can make not only nature's favorite macrocycle but also, if you are adventurous, numerous topologically nontrivial rings.