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Control of Aromaticity and cis-/trans-Isomeric Structure of Non-Planar Hexaphyrin(2.1.2.1.2.1) and Metal Complexes
Songlin Xue1, Daiki Kuzuhara2, Naoki Aratani1
1Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan.
Abstract:
Vinylene-bridged hexaphyrin(2.1.2.1.2.1) was synthesized from dipyrrolyl diphenylethenes by acid-catalyzed condensation reactions. Freebase hexaphyrin(2.1.2.1.2.1) forms a distorted structure with non-aromatic characteristics. The aromaticity and molecular configuration of non-planar hexaphyrin(2.1.2.1.2.1) can be controlled by insertion of metal ions. Freebase and zinc complexes show a distorted structure without macrocyclic aromaticity, whereas copper complexes show a figure-of-eight structure with macrocyclic aromaticity. It is the first example of aromaticity conversion of a distorted expanded porphyrin involving vinylene bridges.
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