Greatness in Simplicity: Efficient Red Room-Temperature Phosphorescence from Simple Halogenated Maleimides with a 2D Layered Structure

Shuaiqi Wang; Jingwei Wang; Qiuqin Huang; Xin Zheng; Zizhu Yao; Shengchang Xiang; Qidan Ling; Zhenghuan Lin

doi:10.1021/acsami.1c23584

Greatness in Simplicity: Efficient Red Room-Temperature Phosphorescence from Simple Halogenated Maleimides with a 2D Layered Structure

ACS Appl Mater Interfaces. 2022 Mar 30;14(12):14703-14711. doi: 10.1021/acsami.1c23584. Epub 2022 Mar 15.

Authors

Shuaiqi Wang¹, Jingwei Wang², Qiuqin Huang¹, Xin Zheng¹, Zizhu Yao¹, Shengchang Xiang¹, Qidan Ling¹, Zhenghuan Lin¹

Affiliations

¹ Fujian Key Laboratory of Polymer Materials, College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, China.
² Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices, School of Chemistry, Biology and Materials Science, East China University of Technology, Nanchang 330013, China.

PMID: 35290015
DOI: 10.1021/acsami.1c23584

Abstract

Herein, two maleimide derivatives substituted by Br (DBM) and I (DIM) with a two-dimensional (2D) layered structure are found to have highly efficient red room-temperature phosphorescence (RTP) at 660 nm in solid state, which is independent of their morphology (crystal, powder, and film). The red RTP of DBM and DIM is closely related to the synergism of n_π-ct-π* transitions and the 2D halogen-bonded network. Interestingly, the red RTP can be excited by visible light of 500 nm, which should be ascribed to the forbidden absorption from the ground state to the triplet state activated in the layered halogen-bonded framework. Due to the rich intermolecular interactions in the rigid layered structure, the red RTP of DBM is very stable under water or external force stimulation. Notably, Hg(II) and Cd(II) ions in a pure aqueous solution result in an opposite change in the RTP intensity of the DBM film. The detection limit of Hg(II) ion is as low as 2.5 × 10^-5 nM, lesser than all reported values. The above results not only provide a new idea for the design of simple and efficient red RTP materials but also make it possible to develop solid-state phosphorescent probes for toxic heavy metal ions in environmental sewage with high sensitivity and selectivity.

Keywords: 2D; RTP; maleimide; red light; sensing.