Fluorescent bent-core mesogens with thiophene-based central unit

ABSTRACT

New bent-core mesogens with thiophene central ring were designed to obtain fluorescent and conductive liquid crystlline phases. Depending on the number of terminal chains and the length of lateral substituent at central unit either calamitic or columnar phases were formed. All the synthesised compounds showed high quantum efficiency of fluorescence in solution, ~0.9, that was however reduced to ~0.15 in condensed state. The light emitted from nematic or columnar phase was linearly polarised. Quenching of fluorescence in condensed state, together with observed red shift of emission maximum wavelength, evidenced formation of J-aggregates or weak excimers. Aggregation was also monitored by dynamic light scattering in water/tetrahydrofuran (THF) solutions.

Graphical abstract

KEYWORDS:

• Polycatenar mesogens
• fluorescent liquid crystals
• columnar phase
• electrochemistry

Acknowledgments

J.M. acknowledges the support by National Science Centre (Poland) under the project 2017/01/X/ST5/00591. K.G. was supported by the National Science Centre (Poland) under grant no. 2017/27/B/ST5/02503. The authors acknowledge access to photoluminescence measurements in solution provided by Prof Jacek Jemielity (Center of New Technologies UW) and thank Dr Ewa Nazaruk (Warsaw University) for carrying out the CV measurements.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessedhere.

Additional information

Funding

This work was supported by the National Science Centre (Poland) [2017/01/X/ST5/00591,2017/27/B/ST5/02503].