Issue 36, 2023

Triplet conformation in chromophore-fused cyclooctatetraene dyes

Abstract

Cyclooctatetraene (COT) has a tub-shaped conformation in its ground non-aromatic state, while it is predicted to have a planar aromatic triplet state. However, COT possesses a non-vertical triplet state and therefore its detection has remained elusive through direct photoexcitation. Recently, fluorescent dyes synthesized by fusing COT with anthracene and phenazine “wings” have shown a large Stokes shift implying a significant conformational change in their excited singlet manifold. Here, using broadband transient absorption spectroscopy supported with electronic structure calculations, we demonstrate that intersystem crossing occurs in the planar COT conformation in these flapping dyes. We confirm that such a planar conformation in the triplet state does not impart aromaticity to the COT backbone, as previously predicted. Our work therefore provides the basis for the requisite structural design principles that would allow for triplet formation from excited singlet states in COT-based functional molecules.

Graphical abstract: Triplet conformation in chromophore-fused cyclooctatetraene dyes

  • This article is part of the themed collection: #MyFirstJMCC

Supplementary files

Article information

Article type
Paper
Submitted
19 juin 2023
Accepted
08 août 2023
First published
08 août 2023

J. Mater. Chem. C, 2023,11, 12243-12253

Author version available

Triplet conformation in chromophore-fused cyclooctatetraene dyes

S. Paul, H. Kitakado, K. Suga, R. Kotani, N. Dey, R. Venkatramani, E. Matito, S. Saito and J. Dasgupta, J. Mater. Chem. C, 2023, 11, 12243 DOI: 10.1039/D3TC02151C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements