The chemistry of polyphyrins 2. Syntheses of hexaphyrins and their metal complexes

The synthesis of eight derivatives of a 26π-electron macrocycle analogous to the porphyrins bearing six pyrrole rings and six methine bridges is described. This chromophore is named hexaphyrin. Owing to the flexibility of their chromophore, hexaphyrins are able to form two kind of binuclear coordination complexes of substantially different geometry