ABSTRACT
A Novel homologous series of liquid crystals, viz, α-4(4’-n-alkoxy cinnamoyloxy) benzoyl-β-4”-pentyloxy phenyl ethylene, has been synthesized. The series consists of eleven homologs. The methyl to pentyl derivatives are not liquid crystalline and the rest of the homologs are enantiotropic liquid crystals. The decyl and dodecyl derivatives of the series are enantiotropically smectogenic in addition to nematogenic in character, but the hexyl, tetradecyl and hexadecyl homolog derivatives of the series are only nematogenic without the exhibition of a smectic phase. The transition temperatures of the novel substances were determined by optical polarizing microscopy equipped with a heating stage. A plot of transition temperatures versus the number of carbon atoms present in the n-alkoxy terminal chain represents the phase behavior of the series. An odd-even effects not observed for the nematic-isotropic transition curve. The textures of the nematic phase are of a threaded or Schlieren type and those of the smectic A and smectic C phases are typical. Analytical and spectral data agree with the molecular structures. The smectic and nematic thermal stabilities are 122 °C and 157 °C, respectively. The smectic phase commences from the decyl homolog. Smectogenic phase lengths vary from 13 °C to 15 °C and the nematogenic phase lengths vary from 11 °C to 46 °C. The series is predominantly nematogenic and partly smectogenic with considerable mesophase length and a middle-ordered melting type. The liquid crystal properties of the present series are compared with structurally similar homologous series.
References
- Marcos, M., Omenat, A., Serrano, J. L., & Ezcurra, A. (1992). A ferroelectric liquid crystal dimer: Synthesis and properties. Mater. 4(4), 285-287
- [2] Hird, M., Toyne, K. J., & Gray, G. W. (1993). Palladium-catalysed cross-coupling reactions in the synthesis of some high polarizability materials. Cryst. 14, 741-761
- Hird, M., Toyne, K. J., Gray, G. W., Day, S. E., & Mc Donnell, D. G. (1993). The synthesis and high optical birefringence of nematogens incorporating 2,6-disubstituted naphthalenes and terminal cyanosubstituent. Cryst. 15, 123-150
- Gray, G. W. (1962). Molecular Structure and the Properties of Liquid Crystal, Academic Press: London and New York. (b) Gray, G. W., & Windsor, P. A. (1974). Liq. Cryst. And Plastic Cryst. Vol. 1., Ellis Horwood Ltd., Chichester, Halsted Press (A Division of John Wiley and Sons. Inc.): New York, London, Ch. 4.
- Dave, J. S., & Vora, R. A. (1970). Liquid Crystals and Ordered Fluids, Plenum Press: New York, p. 477
- Prajapati, A. K., and H. M. Pandya. Effect of a lateral chloro group on azomesogens containing the naphthalene moiety. Molecular Crystals and Liquid Crystals1 (2003) 31-39
- Jadav, N. D., Bharati A. Prajapati, and Ashish K. Prajapati. Azomesogens containing two fused ring moieties: synthesis and characterization. Molecular Crystals and Liquid Crystals 399, 1 (2003) 53-60
- L. Chauhan, R. N. Pandya & A. V. Doshi(2011)Synthesis and Mesomorphism of Novel Liquid Crystalline: p-(p′-n-Alkoxy Benzoyloxy) Methyl Cinnamates,Molecular Crystals and Liquid Crystals, 548: 1, 228-234, DOI: 10.1080/15421406.2011.591664
- V. Doshi & N. G. Makwana(2011)Homologous Series of Azomesogens: 4-(4′-n-Alkoxy Benzoyloxy)-3-Chloro Phenylazo-2″-Chlorobenzenes,Molecular Crystals and Liquid Crystals, 548: 1, 220-227, DOI: 10.1080/15421406.2011.590376
- B. Patel, V. R. Patel & A. V. Doshi(2012)Synthesis and Mesomorphism of Novel Liquid-Crystalline Isobutyl-p-(p′-n-Alkoxy Cinnamoyloxy) Cinnamates,Molecular Crystals and Liquid Crystals, 552: 1, 3-9, DOI: 10.1080/15421406.2011.591659
- Chauhan H.N., Shah R.R., & Doshi, A. V. (2013). Synthesis and Liquid Crystalline Properties of Novel Ethylene Derivatives. Cryst. Liq. Cryst. 577, pp. 36-43
- Chauhan, H. N., & Doshi, A. V. (2012). Ethylene Derivatives of Liquid Crystalline Properties: Homologous Series : α-4-[-4’-n-Alkoxy Cinnamoyloxy] benzoyl β-phenyl ethylenes. Der Pharma Chemica, 4(3), 977-983
- Chaudhari, R. P., & Doshi, A. V. (2012). Synthesis and study of benzo-ester homologous series of ethylene derivatives: α-4-[4’-n-Alkoxy cinnamoyloxy benzoyl ] β-2”-nitro phenyl ethylenes. Der Pharma Chemica, 4(3), 1113-1119
- Bhola, G. N., and U. C. Bhoya. Mesomorphism Dependence on Molecular Flexibility and Molecular Rigidity. Molecular Crystals and Liquid Crystals 1 (2015) 46-54
- Steiber N. Strong or Weak Handgrip? Normative Reference Values for the German Population across the Life Course Stratified by Sex, Age, and Body Height. PLoS One. 2016 Oct 4; 11(10): e0163917. doi: 10.1371/journal.pone.0163917
- Bhola, G. N., and U. C. Bhoya. Mesomorphism dependence on heterocyclic end group. Molecular Crystals and Liquid Crystals1 (2016): 11-19
- Badran, Aya I., Hamed M. EL-Fatatry, and Sherin F. Hammad. Simultaneous Estimation of Telmisartan and Amlodipine by Second Derivative Spectrophotometric Method and First Derivative Ratio-Spectrophotometric Method. Am J Pharm Tech Res 2 (2015) 172-189
- Patel, Priya K., and R. R. Shah. Study of mesomorphism and laterally substituted nitro group. Molecular Crystals and Liquid Crystals1 (2016) 41-49
- Solanki, Ravindra, and R. B. Patel. Study of the Effects of lateral Substitution (Bromo) on Mesomorphic Behaviours of Chalconyl Ester Derivatives. International Letters of Chemistry, Physics and Astronomy 64 (2016) 135
- Heppke, Gerd, et al. Selenol Esters—A Novel Class of Liquid‐Crystal Compounds. Angewandte Chemie International Edition in English5 (1977) 318-319
- Hird, Michael. Fluorinated liquid crystals–properties and applications. Chemical Society Reviews12 (2007): 2070-2095
- Hoyt, Andrea E., and Brian C. Benicewicz. Rigid rod molecules as liquid crystal thermosets. II. Rigid rod esters. Journal of Polymer Science Part A: Polymer Chemistry12 (1990) 3417-3427
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