CC BY-NC-ND 4.0 · Organic Materials 2020; 02(01): 033-040
DOI: 10.1055/s-0040-1701249
Original Article
The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/). (2020) The Author(s).

Solid-State Fluorescence Enhancement of Bromine-Substituted Trans-Enaminone Derivatives

Hua Li
a   State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
b   University of Science and Technology of China, Hefei 230026, China
,
a   State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
b   University of Science and Technology of China, Hefei 230026, China
,
a   State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
b   University of Science and Technology of China, Hefei 230026, China
,
a   State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
,
a   State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
b   University of Science and Technology of China, Hefei 230026, China
,
a   State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
b   University of Science and Technology of China, Hefei 230026, China
,
a   State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
b   University of Science and Technology of China, Hefei 230026, China
› Author Affiliations
Funding Information This work was financially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB12010200) and the National Natural Science Foundation of China (Grant Nos. 51833009, 21674111, 21574131, 51973211, and 21322403).
Further Information

Publication History

Received: 29 September 2019

Accepted after revision: 02 December 2019

Publication Date:
30 January 2020 (online)


Abstract

Halogen bonding, as a kind of intermolecular interaction, has rarely been used to tune solid-state emission properties of luminescent materials, especially fluorescent materials. Herein, three trans-enaminone (TE) derivatives (nonbrominated TE, monobrominated BrTE, and tribrominated Br3TE) with aggregation-induced emission property have been designed and synthesized. Two types of BrTE crystals (BrTE-B and BrTE-G) with different fluorescence properties were obtained. It was observed that their solid-state fluorescence has been enhanced by the formation of halogen bonding. In particular, the crystal BrTE-G containing Br…π interactions exhibits a fluorescence quantum yield (9.6%) nearly sevenfold higher than BrTE-B, the crystal without halogen bonding (1.4%), and fivefold higher than the nonbrominated TE derivative (2.1%). By careful inspection of the single-crystal data and theoretical calculations, the high fluorescence quantum yield of BrTE-G appears to be due to halogen-bonding interactions as well as multiple stronger intermolecular interactions which may restrain molecular motions, leading to the reduced nonradiative decay rate and the enhanced radiative decay rate. Additionally, increasing the number of bromine substituents may further promote the radiative decay rate, explaining therefore the higher fluorescence quantum yield (12.5%) of Br3TE.

Supporting Information

Supporting information for this article is available online at https://doi.org/10.1055/s-0040-1701249.


Supporting Information