Issue 17, 2019

Efficient and versatile mechanochromic luminescence of phenanthroimidazolylbenzothiadiazoles: tricolor switching and directional control over the chromism

Abstract

Mechanochromic luminescence (MCL) refers to the mechanical-stimuli-responsive reversible color change of solid-state-emissive dyes. In spite of recent extensive studies on the development of MCL dyes, most of these display bicolor MCL that usually manifests in bathochromic shifts of the emission color in response to mechanical stimuli. Herein, phenanthroimidazolylbenzothiadiazoles are described as a new class of highly emissive solid-state fluorophores that exhibit more versatile MCL properties. Depending on the substituent on the phenyl group of the benzothiadiazole ring, bathochromically or hypsochromically shifted bicolor MCL as well as tricolor MCL are observed for these dyes. Powder X-ray diffraction and differential scanning calorimetry measurements for the bicolor MCL systems indicated that the mechanism of the emission-color change upon grinding is based on typical crystalline-to-amorphous phase transitions. To investigate the tricolor MCL system in detail, single-particle-level fluorescence microscopy has been applied for the first time, which allowed distinguishing three states with different emission properties. The versatility of the present MCL system was attributed to the formation of different crystal structures by introducing various substituents on the aforementioned phenyl group. These results provide useful insights into generating diverse MCL dyes in the future and thus promote the practical applications of MCL systems.

Graphical abstract: Efficient and versatile mechanochromic luminescence of phenanthroimidazolylbenzothiadiazoles: tricolor switching and directional control over the chromism

Supplementary files

Article information

Article type
Paper
Submitted
10 Jan 2019
Accepted
08 Mac 2019
First published
09 Mac 2019

J. Mater. Chem. C, 2019,7, 4988-4998

Efficient and versatile mechanochromic luminescence of phenanthroimidazolylbenzothiadiazoles: tricolor switching and directional control over the chromism

S. Nagai, M. Yamashita, T. Tachikawa, T. Ubukata, M. Asami and S. Ito, J. Mater. Chem. C, 2019, 7, 4988 DOI: 10.1039/C9TC00157C

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