Novel fluorescence liquid crystals based on thiophene-vinylnitrile Schiff-base derivatives

ABSTRACT

This paper reported the first example of thiophene-containing AIE fluorescence liquid crystals. Thiophene-vinylnitrile Schiff-base derivatives 5 with one alkyl chain and 6 with two alkyl chains were prepared conveniently in yields of 86% and 88%, respectively. They exhibited the smectic phases from 91.5 to 130.6℃ for sample 5 and 71.3 to 120.2℃ for sample 6. They displayed excellent fluorescence in aggregated states of solid film and mesophase. The absolute fluorescence quantum yields in solid film were as high as 0.64 for samples 5 and 0.76 for sample 6, respectively. These results suggested thiophene-vinylnitrile Schiff-base derivatives 5 and 6 were excellent fluorescence liquid crystals and the multiple alkyl chains on thiophene-vinylnitrile Schiff-base derivatives were favourable for the low temperature of mesophase and high fluorescence.

GRAPHICAL ABSTRACT

KEYWORDS:

• Thiophene
• fluorescence
• mesophase
• aggregation-induced emission

Acknowledgments

Financial support from the National Natural Science Foundation of China (No: 21406036), Fujian Science and Technology Project (No. 2019N0010) and the National Undergraduate Innovation Program in Fujian Normal University (2022) were greatly acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

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Additional information

Funding

This work was supported by the National Natural Science Foundation of China [21406036]; Fujian Science and Technology Project [2019N0010]; National Undergraduate Innovation Program in Fujian Normal University [2022].