A Pentacene‐based Nanotube Displaying Enriched Electrochemical and Photochemical Activities. Issue 4 (27th December 2018)

• Record Type: Journal Article
• Authors: Kuroda, Kiyonori; Yazaki, Kohei; Tanaka, Yuya; Akita, Munetaka; Sakai, Hayato; Hasobe, Taku; Tkachenko, Nikolai V.; Yoshizawa, Michito
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 4(2019)
• Page Start: 1115
• Page End: 1119
• Publication Date: 2018-12-27
• Subjects: macrocycles -- nanotubes -- pentacene -- singlet fission -- triplet states; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201812976
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: 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. Abstract : 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.