Cargando…

Light-Responsive Hexagonal Assemblies of Triangular Azo Dyes

The rational design of small building block molecules and understanding their molecular assemblies are of fundamental importance in creating new stimuli-responsive organic architectures with desired shapes and functions. Based on the experimental results of light-induced conformational changes of fo...

Descripción completa

Detalles Bibliográficos
Autores principales: Han, Mina, Moe, Khin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9317042/
https://www.ncbi.nlm.nih.gov/pubmed/35889253
http://dx.doi.org/10.3390/molecules27144380
_version_ 1784754961453678592
author Han, Mina
Moe, Khin
author_facet Han, Mina
Moe, Khin
author_sort Han, Mina
collection PubMed
description The rational design of small building block molecules and understanding their molecular assemblies are of fundamental importance in creating new stimuli-responsive organic architectures with desired shapes and functions. Based on the experimental results of light-induced conformational changes of four types of triangular azo dyes with different terminal functional groups, as well as absorption and fluorescence characteristics associated with their molecular assemblies, we report that aggregation-active emission enhancement (AIEE)-active compound (1) substituted with sterically crowded tert-butyl (t-Bu) groups showed approximately 35% light-induced molecular switching and had a strong tendency to assemble into highly stable hexagonal structures with AIEE characteristics. Their sizes were regulated from nanometer-scale hexagonal rods to micrometer-scale sticks depending on the concentration. This is in contrast to other triangular compounds with bromo (Br) and triphenylamine (TPA) substituents, which exhibited no photoisomerization and tended to form flexible fibrous structures. Moreover, non-contact exposure of the fluorescent hexagonal nanorods to ultraviolet (UV) light led to a dramatic hexagonal-to-amorphous structure transition. The resulting remarkable variations, such as in the contrast of microscopic images and fluorescence characteristics, were confirmed by various microscopic and spectroscopic measurements.
format Online
Article
Text
id pubmed-9317042
institution National Center for Biotechnology Information
language English
publishDate 2022
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-93170422022-07-27 Light-Responsive Hexagonal Assemblies of Triangular Azo Dyes Han, Mina Moe, Khin Molecules Article The rational design of small building block molecules and understanding their molecular assemblies are of fundamental importance in creating new stimuli-responsive organic architectures with desired shapes and functions. Based on the experimental results of light-induced conformational changes of four types of triangular azo dyes with different terminal functional groups, as well as absorption and fluorescence characteristics associated with their molecular assemblies, we report that aggregation-active emission enhancement (AIEE)-active compound (1) substituted with sterically crowded tert-butyl (t-Bu) groups showed approximately 35% light-induced molecular switching and had a strong tendency to assemble into highly stable hexagonal structures with AIEE characteristics. Their sizes were regulated from nanometer-scale hexagonal rods to micrometer-scale sticks depending on the concentration. This is in contrast to other triangular compounds with bromo (Br) and triphenylamine (TPA) substituents, which exhibited no photoisomerization and tended to form flexible fibrous structures. Moreover, non-contact exposure of the fluorescent hexagonal nanorods to ultraviolet (UV) light led to a dramatic hexagonal-to-amorphous structure transition. The resulting remarkable variations, such as in the contrast of microscopic images and fluorescence characteristics, were confirmed by various microscopic and spectroscopic measurements. MDPI 2022-07-08 /pmc/articles/PMC9317042/ /pubmed/35889253 http://dx.doi.org/10.3390/molecules27144380 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Han, Mina
Moe, Khin
Light-Responsive Hexagonal Assemblies of Triangular Azo Dyes
title Light-Responsive Hexagonal Assemblies of Triangular Azo Dyes
title_full Light-Responsive Hexagonal Assemblies of Triangular Azo Dyes
title_fullStr Light-Responsive Hexagonal Assemblies of Triangular Azo Dyes
title_full_unstemmed Light-Responsive Hexagonal Assemblies of Triangular Azo Dyes
title_short Light-Responsive Hexagonal Assemblies of Triangular Azo Dyes
title_sort light-responsive hexagonal assemblies of triangular azo dyes
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9317042/
https://www.ncbi.nlm.nih.gov/pubmed/35889253
http://dx.doi.org/10.3390/molecules27144380
work_keys_str_mv AT hanmina lightresponsivehexagonalassembliesoftriangularazodyes
AT moekhin lightresponsivehexagonalassembliesoftriangularazodyes