New isothiocyanato liquid crystals containing thieno[3,2-b]thiophene central core

ABSTRACT

New isothiocyanato liquid crystal (LC) materials based on thieno[3,2-b]thiophene core have been synthesised and characterised. Their mesomorphic and physical properties were evaluated. The results indicate that most of the new compounds exhibit only enantiotropic smectic A phases with high clearing points, and the difluorinated compounds (A3 and A6), in particular, also display a stable nematic phase with low melting points. Compared with the corresponding biphenyl and thiophene-phenyl analogues, these thieno[3,2-b]thiophene-based compounds possess increased birefringence (the highest value found to be 0.40) and mesogenic phase intervals. These new thieno[3,2-b]thiophene-based LCs exhibit a high birefringence and a high clearing point and are of potential use as components of high birefringence mixtures.

Graphical Abstract

KEYWORDS:

• Thieno[3
• 2-b]thiophene
• isothiocyanate
• liquid crystal
• birefringence
• lateral fluorination

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Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is supported by the Defense Industrial Technology Development Program of China [grant number: B0520132007] and by Administry of Education [joint Fund N. 6141A02022219].