Issue 10, 2023

Red-light photoswitching of indigos in polymer thin films

Abstract

Through simple synthetic derivatisation, the parent indigo dye becomes a red-light EZ photoswitch exhibiting negative photochromism and tuneable thermal isomerisation kinetics. These attributes make indigo derivatives extremely attractive for applications related to materials and living systems. However, there is a lack of knowledge in translating indigo photoswitching dynamics from solution to solid state – the environment crucial for most applications. Herein, we study the photoswitching performance of six structurally distinct indigo derivatives in five polymers of varying rigidity. Three key strategies are identified to enable efficient photoswitching under red (660 nm) light: (i) choosing a soft polymer matrix to minimise its resistance toward the isomerisation, (ii) creating free volume around the indigo molecules through synthetic modifications, and (iii) applying low dye loading (<1% w/w) to inhibit aggregation. These strategies are shown to improve both photostationary state distributions and the thermal stability of the Z isomer. When all three strategies are implemented, the isomerisation performance (>80% Z form in the photostationary state) is nearly identical to that in solution. These findings thus pave the way for designing new red-light photochromic materials based on indigos.

Graphical abstract: Red-light photoswitching of indigos in polymer thin films

Supplementary files

Article information

Article type
Edge Article
Submitted
09 Dez 2022
Accepted
29 Jan 2023
First published
22 Feb 2023
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY-NC license

Chem. Sci., 2023,14, 2482-2488

Red-light photoswitching of indigos in polymer thin films

K. Kuntze, J. Viljakka, M. Virkki, C. (. Huang, S. Hecht and A. Priimagi, Chem. Sci., 2023, 14, 2482 DOI: 10.1039/D2SC06790K

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, 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 commercial 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