Ethynylene-linked Figure-Eight Octaphyrin(1.2.1.1.1.2.1.1): Synthesis and Characterization of Its Two Oxidation States

Sahoo, K. C.; Majewski, M. A.; Stępień, M.; Rath, H.
J. Org. Chem. 2017, 82, 8317-8322 | view at publisher's site

An octaphyrin(1.2.1.1.1.2.1.1) containing two conjugated ethynylene bridges has been synthesized and characterized. The macrocycle reveals complex conformational dynamics dependent on its protonation and oxidation state. The [40]annulenoid macrocycle and its [38]annulenoid oxidized form display residual macrocyclic ring currents. In spite of its low apparent aromaticity the new octaphyrin is a potent chromophore with a vis-NIR absorption profile strongly influenced by the redox and acid–base chemistry.