Yating Wen, Shuaiqiang Zhao, Zhongzhao Yang, Zhiqiang Yang, Fan Zhang, Yuxiang Dai, Shitong Zhang, Haichao Liu* and Bing Yang*,
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引用次数: 0
Abstract
Thioxanthone (TX) and its derivatives as important triplet sensitizers and photoinitiators have attracted a great deal of interest in photochemical studies; however, their luminescence properties receive less attention, which limits the understanding of the correlation between their structures and properties. Here, a series of alkyl chains (methyl (Me), ethyl (Et), propyl (n-Pr), and isopropyl (i-Pr)) are introduced on the 2-position and 4-position of TX to mainly investigate the correlation between the packing structure and the luminescence property of the resulting crystals. The alkyl substituents are found to have a negligible effect on the photophysical properties of TX-2-alkyl and TX-4-alkyl compounds in their dispersed states; however, single-crystal X-ray diffraction analysis and photophysical measurement demonstrate that the TX-2-alkyl and TX-4-alkyl crystals present distinctive packing motifs, leading to different luminescence properties. The TX-2-Me, TX-4-Me, TX-4-n-Pr, and TX-4-i-Pr crystals show a dimeric π–π packing motif; the TX-2-n-Pr and TX-4-Et crystals exhibit a long-range π–π monomer packing motif and the TX-2-Et and TX-2-i-Pr crystals display a herringbone packing motif. It is found that a change in molecular packing motif from dimeric π–π packing and monomeric π–π packing to herringbone packing generally corresponds to a gradually blue-shifted fluorescence and room-temperature phosphorescence (RTP) emission wavelengths. This work will provide a comprehensive understanding of the effect of the alkyl substituents on the packing structures and luminescence properties of the TX luminophore.
期刊介绍:
The aim of Crystal Growth & Design is to stimulate crossfertilization of knowledge among scientists and engineers working in the fields of crystal growth, crystal engineering, and the industrial application of crystalline materials.
Crystal Growth & Design publishes theoretical and experimental studies of the physical, chemical, and biological phenomena and processes related to the design, growth, and application of crystalline materials. Synergistic approaches originating from different disciplines and technologies and integrating the fields of crystal growth, crystal engineering, intermolecular interactions, and industrial application are encouraged.