Internally 1,4-Phenylene-Bridged meso Aryl-Substituted Expanded Porphyrins: The Decaphyrin and Octaphyrin Cases

摘要

The chemistry of expanded porphyrins is the current focus of intensive research because of their unique properties.Among their many expected properties,extensive aromaticity is realized in expanded porphyrins such as sapphyrins,rubyrins,and hexaphyrins.However,such aromaticity becomes increasingly difficult to obtain with larger expanded porphyrins,particularly for systems larger than octapyrroles,mainly because of intrinsic conformational distortion from planarity.Rare examples are the 34pi-electron core-modified octaphyrin and 30pi-electron cyclo[8]pyrrole,both of which exhibit planar conformations and strong aromaticity,thus underscoring the influence of the conformation of the expanded porphyrins upon their electronic structures.