Liquid crystalline oligomers derived from cholesterol: synthesis and columnar mesomorphism

ABSTRACT

The novel columnar liquid crystals based on symmetric hairpin-shaped cholesterol tetramers bridged by rigid or hydrogen-bonding Schiff-base spacers were prepared by reacting cholesterol dimer with phenylenediamines or dihydrazides in yields of 70–85%. Structural characterisation of these new compounds had been achieved by infrared, nuclear magnetic resonance and mass spectrometry. Their mesomorphic properties were investigated by polarising optical microscopy, differential scanning calorimetry and X-ray diffraction. They exhibited good hexagonal columnar mesophase with three molecules in a disc of the columnar hexagonal state. This study implied that the symmetric cholesterol tetramers with rigid cores or hydrogen-bonding cores prefer to columnar mesophase.

GRAPHICAL ABSTRACT

KEYWORDS:

• Cholesterol
• tetramer
• synthesis
• mesophase

Acknowledgements

Financial support from the National Natural Science Foundation of China (No: 21406036), Fujian Natural Science Foundation of China (No. 2017J01571) and the Chemical Talent Program of Fujian Normal University was greatly acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

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Additional information

Funding

Financial support from the National Natural Science Foundation of China [No. 21406036]; Fujian Natural Science Foundation of China [No. 2017J01571] and the Chemical Talent Program of Fujian Normal University was greatly acknowledged