Tunable Fluorescence and Afterglow in Organic Crystals for Temperature Sensing.

Jian-Xin Wang,Qing-Zheng Yang,Zheng-Fei Liu,Ling-Ya Peng,Li-Ya Niu,Xin Zhu,Ganglong Cui

doi:10.1021/acs.jpclett.2c00168

Jian-Xin Wang, Qing-Zheng Yang + Show 5 more

Open Access

https://doi.org/10.1021/acs.jpclett.2c00168

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Abstract

The modulation of the properties of emission from multiple emission states in a single-component organic luminescent material is highly desirable in data anticounterfeiting, information storage, and bioapplications. Here, a single-component luminescent organic crystal of difluoroboron diphenyl β-diketonate with controllable multiple emission colors is successfully reported. The temperature-dependent luminescence experiments supported by high-level theoretical calculations demonstrate that the ratio of the fluorescence between the monomer and excimer and the phosphorescence maxima of the excimer can be effectively regulated. In addition, the temperature-dependent fluorescence and afterglow dual-emission color changes provide a new strategy for the design of highly accurate double-checked temperature sensors.

Highlights

The modulation of the properties of emission from multiple emission states in a single-component organic luminescent material is highly desirable in data anticounterfeiting, information storage, and bioapplications
Solid organic luminescent materials with multiple emission colors have attracted a great deal of attention due to their fascinating molecular compositions, rich photophysical properties, and enormous potentials in optoelectronic and biomedical applications.[1−14] Multicolor emission systems prepared from composite materials have been widely investigated
Difluoroboron β-diketonate derivatives are some of the potential materials for studying stimulusresponsive luminescence systems with multiple emissions due to their modifiable molecular conformation and intermolecular interaction.[20,26,44−50] In addition, the n−π electronic transition of difluoroboron β-diketonate enables room-temperature phosphorescence and afterglow emission through appropriate regulation of the π system according to El-Sayed’s rule.[17,51−53] These characteristics fully provide the prerequisite for the establishment of a multiple-emission system in a singlecomponent luminescent material

Summary

Introduction

The modulation of the properties of emission from multiple emission states in a single-component organic luminescent material is highly desirable in data anticounterfeiting, information storage, and bioapplications. The experimental and theoretical calculation results demonstrate that a temperature-dependent fluorescence color change from yellow-green (540 nm, 300 K) to blue (470 nm, 77 K) and an afterglow color change from yellow (560 nm, 300 K) to red (650 nm, 77 K) are due to temperature-modulated intermolecular interactions. The emission band of the monomer at 400 nm gradually red-shifted to 470 nm, which could probably be caused by the enhanced intermolecular interaction at high concentrations.

Results

Conclusion