A Pentacene‐based Nanotube Displaying Enriched Electrochemical and Photochemical Activities.

Unlike previously well‐studied, acyclic pentacene oligomers, the first synthesis of a cyclic pentacene trimer with a fixed tubular conformation is reported. A short‐step synthesis starting from common pentacenequinone yielded the target molecule with a 1.5 nanometer length and a subnanometer pore. Steady‐state spectroscopic analyses revealed that the close proximity of the non‐conjugated, three pentacene chromophores allows the nanotube to display stepwise electrochemical/chemical oxidation characteristics. Furthermore, time‐resolved transient absorption measurements elucidated the generation of an excited triplet state of the nanotube, with high quantum yield reaching about 180 % through intramolecular singlet fission and a very long triplet lifetime. A pentacene‐based nanotube was synthesized for the first time. The close proximity of the three non‐conjugated pentacene chromophores allows the nanotube to display stepwise electrochemical/chemical oxidation characteristics. Time‐resolved transient absorption measurements show the generation of an excited triplet state, with a high quantum yield (ca. 180 %) and very long triplet lifetime, through intramolecular singlet fission. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie International Edition is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)