The novel rufigallol-based liquid crystals with cholesterol units: synthesis, mesomorphic and photophysical properties

ABSTRACT

Three novel rufigallol derivatives with four alkyl chains and two cholesteric units 6a, 6b and 6c were prepared in yields of 83–88%. The mesomorphic properties were investigated by DSC, POM and XRD analysis, suggesting that compounds 6a, 6b and 6c possess the ordered hexagonal columnar mesophase. The long alkyl chains contribute to the low phase transition temperature. Sample 6c with four dodecyl chains and two cholesterol units is a room temperature liquid crystal between 31°C and 87°C. Compounds 6a, 6b and 6c also have good fluorescence emission between 400 nm and 500 nm. The studies on CD spectra implied that the chiralities of cholesterol moieties are successfully transferred to the liquid crystalline core. Samples 6a, 6b and 6c are the first fluorescence liquid crystal based on rufigallol core with chiral cholesterol units.

GRAPHICAL ABSTRACT

KEYWORDS:

• Rufigallol
• cholesterol
• synthesis
• mesophase
• luminescence

Acknowledgments

This work was financially supported by the National Natural Science Foundation of China (No: 21406036), Fujian Natural Science Foundation of China (No. 2017J01571) and Fuzhou science and technology project (2018-G-44).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [21406036].