Luminous and fluorescent cyanobiphenyls exhibiting super-cooled nematic phases

ABSTRACT

A new series of liquid crystal dimers, 4-cyano-1,3-phenylene bis(4-((4’-cyano-[1,1’−biphenyl]-n-yl)oxy)alkanoate), has been synthesised and confirmed for their molecular structure using standard spectroscopic techniques. Thermal behaviour is assessed using optical polarising microscope (OPM), differential scanning calorimetry (DSC), and X-ray diffraction. Interestingly, all the dimers exhibit a super-cooled nematic phase without crystallisation during cooling cycles. These molecules self-assemble with head-on aggregation assessed by UV–Visible absorption spectra, and they also have a distinct fluorescence characteristic. A super-cooled nematogens self-assemble into head-on aggregation with a fluorescence property. Moreover, the materials were studied for their fluorescence properties and proved to be fluorescence active, making them excellent candidates to be used in designing photo-responsive optical sensor devices.

GRAPHICAL ABSTRACT

A class of dimers with remarkable luminescent properties at room temperatures, holding potential for advancements in photonics.

KEYWORDS:

• Cyanobiphenyls
• reduced symmetry
• nematic
• fluorescent
• H-aggregation

Acknowledgments

G. Shanker extends gratitude to the University Grants Commission (UGC-FRP), New Delhi, India. Furthermore, recognition is extended for the financial support received from VGST K-FIST(L2)/GRD 1021/118/2022-2023/94. We extend our gratitude to Prof. Shivraj Y, Department of Chemistry, Bangalore University, for granting us permission to conduct UV–Visible spectrophotometer studies.

Disclosure statement

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

Supplementary data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/02678292.2023.2294959

Additional information

Funding

The work was supported by the Vision Group on Science and Technology [VGST K-FIST(L2)/GRD 1021/118/2022-2023/94].