Photochromic and fluorescence switching behavior of triazole-functionalized fulgimides: Experimental and theoretical study
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Date
2026-05-11
Authors
Ally, Khamis Nassor
Tsere, Melkizedeck Hiiti
Vuai, Said Ali
Lameck, Azaria Stephano
Öztürk, Leyla
Köse, Mahmut
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Integrating photochromism and fluorescence switching within a single molecular platform remains a central
challenge in the development of light-regulated functional materials. Here, we report a structure-encoded design
strategy based on the direct covalent incorporation of a 1,2,4-triazole unit into the imide framework of
fulgimides, yielding three new photoresponsive molecules (4E–6E). Experimentally, all compounds exhibit photochromism
based on the interconversion between open and closed forms. This is accompanied by large visiblerange
spectral contrast and reversible fluorescence ON/OFF switching under alternating UV and visible light.The
open-ring forms are strongly emissive, while photoinduced cyclization produces systematic fluorescence quenching
(20–40%) governed by intramolecular energy transfer to the conjugated closed-ring core. Density functional
and time-dependent DFT calculations quantitatively reproduce the observed experimental absorption behavior
and reveal pronounced π-delocalization and HOMO-LUMO gap narrowing upon ring closure, establishing clear
structure–property relationships. Among the series, compound 6E shows the most favorable electronic and optical
characteristics. These results identify triazole-imide coupling as a generalizable molecular engineering route
for multifunctional organic photo-switches and advance their potential for optical memory, sensing, and adaptive
photonic applications.
Description
This Journal Articles was published by Elsevier
Keywords
Keywords: Photochromism Fulgide Fulgimide Triazole Fluorescence switch