Changes in macrocyclic aromaticity and formation of a charge-separated state by complexation of expanded porphyrin and C60

Abstract

Significant changes of macrocyclic aromaticity in expanded porphyrins through C-60 complexation were studied by H-1 NMR spectroscopy and nucleus-independent chemical shift calculations. This work is a detailed research study of how the formation of a complex of dual aromatic expanded porphyrin with fullerene affects the electron densities in the main conjugation pathways and meso-substituents. Furthermore, we found that the formation of the photoinduced charge-separated state and the triplet excited-state populations of the bowl-shaped and rigid expanded porphyrin can be controlled by a simple complexation with C-60.