Synthesis, Characterization and Mesomorphic Study of Homologous Series Linking Azo-Ester Bearing tert-Butyl Terminal Group

https://doi.org/10.65770/LRWY4450

ABSTRACT

A new homologues series of azo-ester containing tert-butyl terminal group has been synthesised and investigated for its mesomorphic properties. The series consists of total eleven homologues (A₁-A₁₄) in which lower homologues (A₁-A₃) are non-mesomorphic in nature due to lack of molecular flexibility. The higher homologues (specifically A₄–A₁₄) demonstrate consistent enantiotropic nematic phases. The liquid crystal phase remains stable at broad range of temperatures. The phase transition temperatures and characteristic textures of homologues were identified via polarised optical microscopy (POM) using heating stage and differential scanning calorimetry (DSC). The observed texture of nematic phase is schlieren or threaded. Thermal, analytical and spectral (IR, ¹H NMR, Mass analysis) data confirmed the molecular structure.

References

• Lagerwall, J. P. F., & Scalia, G. (2012). A new era for liquid crystal research: Applications of liquid crystals in soft matter nano-, bio- and microtechnology. Current Applied Physics, 12(6), 1387–1412. https://doi.org/10.1016/j.cap.2012.03.019
• Abbott, N. L., Kim, Y.-K., Noh, J., & Nayani, K. (2019). Soft matter from liquid crystals. Soft Matter, 15(35), 6913–6924. https://doi.org/10.1039/C9SM01424A
• Zhang, R., Mozaffari, A., & de Pablo, J. J. (2021). Autonomous materials systems from active liquid crystals. Nature Reviews Materials, 6, 437–453. https://doi.org/10.1038/s41578-020-00272-x
• Miskovic, V., Malafronte, E., Minetti, C., Machrafi, H., Varon, C., & Iorio, C. S. (2022). Thermotropic liquid crystals for temperature mapping. Frontiers in Bioengineering and Biotechnology, 10, 806362. https://doi.org/10.3389/fbioe.2022.806362

• Collings, P. J., & Hird, M. (2017). Introduction to liquid crystals: Chemistry and physics (2nd ed.). CRC Press. https://doi.org/10.1201/9781315272630

• Demus, D., Goodby, J., Gray, G. W., Spiess, H.-W., & Vill, V. (Eds.). (1998). Handbook of liquid crystals (Vol. 1). Wiley-VCH. https://doi.org/10.1002/9783527619272

• Bisoyi, H. K., & Li, Q. (2016). Light-directed dynamic chirality switching in liquid crystals. Chemical Reviews, 116(24), 15089–15166. https://doi.org/10.1021/acs.chemrev.6b00154
• Imrie, C. T., & Henderson, P. A. (2007). Liquid crystal dimers and higher oligomers: Between monomers and polymers. Chemical Society Reviews, 36(12), 2096–2124. https://doi.org/10.1039/B615359C
• Tschierske, C. (2013). Development of structural complexity by liquid-crystal self- Angewandte Chemie International Edition, 52(34), 8828–8878. https://doi.org/10.1002/anie.201300872
• Ikeda, T., & Tsutsumi, O. (1995). Optical switching and image storage by means of azobenzene liquid-crystal films. Science, 268(5219), 1873–1875. https://doi.org/10.1126/science.268.5219.1873
• Jágerová, D., Šmahel, M., Poryvai, A., Macháček, J., Novotná, V., & Kohout, M. (2021). Photosensitive bent-core liquid crystals with laterally substituted azobenzene unit. Crystals, 11(10), 1265. https://doi.org/10.3390/cryst11101265
• Bhoya, U. C., & Doshi, A. V. (2005). Mesomorphic properties of Schiff base ester derivatives. Journal of the Indian Chemical Society, 82, 143–145.
• Rakhasia, P. K., Bhola, G. N., & Bhoya, U. C. (2015). Study of the effect of chalconyl central bridge on mesomorphism. International Letters of Chemistry, Physics and Astronomy, 61, 19–27. https://doi.org/10.56431/p-du8g5v
• Bhola, G. N., & Bhoya, U. C. (2016). Molecular structural flexibility dependence of mesomorphism through ortho-substituted bromo group. Molecular Crystals and Liquid Crystals, 630(1), 188–196. https://doi.org/10.1080/15421406.2016.1146941

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WSN 216 (2026) 93-107

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