Synthesis and mesomorphic characterisation of coumarin-Schiff base and carboxylate molecules

Liquid Crystals, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 10

Published: Nov. 5, 2024

Three novel sets of coumarin-based derivatives viz. Schiff's bases from 2-oxo-2 h-chromene-3-carboxylic acid with terminal alkyl benzene and biphenyl cores, methyl- or ethyl-group-derived coumarin esters 7-hydroxy-4-methyl-2 h-chromen-2-one, ethyl-7-hydroxy-2-oxo-2 h-chromene-3-carboxylate were synthesised characterised for mesomorphic properties. The structures the newly prepared compounds confirmed by FT-IR, 1H-NMR, 13C-NMR, elemental analysis. mesophase textures all observed under a polarising optical microscope, transition temperature enthalpy change data measured recorded using differential scanning calorimetry. Most exhibit smectic nematic mesomorphism monotropically enantiotropically. Thermal stability was investigated thermal gravimetric analysis (TGA).

Language: Английский

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Coumarin Schiff base derivatives with alkyl 4’-formyl-biphenyl-4-carboxylate: design, synthesis, mesomorphic studies and DFT calculations

Liquid Crystals, Journal Year: 2024, Volume and Issue: 51(10), P. 1664 - 1675

Published: May 10, 2024

Symmetric and unsymmetric homologous series of coumarin Schiff base derivatives with alkyl 4'-formyl-biphenyl-4-carboxylate have been synthesised studied for their mesomorphic behaviour. In the symmetric BPES(6–16), alkoxy chain length was varied at both ends molecules n = 6,8,10,12,14,16, while in 10BPEU(2–12), end only (n 2–8,10,12). series, compounds BPES(6–10) 6,8,10) exhibited enantiotropic smectic A (SmA) mesophase, C (SmC) mesophase cooling cycle only. SmC became prominent on increasing 12,14,16 BPES(12–16). compound 2 showed monotropic nematic highly stable (~165 °C) SmA mesophase. Higher analogues were turned biphasic as well during scan Compound 12 (~92 °C). VT-XRD analysis 12, tilted Further DFT calculations investigated un/symmetric along literature similar variations compared various structural (length, aspect ratio) electronic (dipole moment, polarisability) parameters to establish correlation observed

Language: Английский

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Coumarin Schiff Base Derivatives with Asymmetric Naphthalene: Synthesis, Mesomorphic studies and DFT Calculations

Journal of Molecular Structure, Journal Year: 2024, Volume and Issue: unknown, P. 140703 - 140703

Published: Nov. 1, 2024

Language: Английский

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New Molecularly Flexible Self-assembling Benzothiadiazole Derivatives: Mesomorphism and DFT Investigations

Journal of Molecular Structure, Journal Year: 2024, Volume and Issue: unknown, P. 140138 - 140138

Published: Sept. 1, 2024

Language: Английский

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Synthesis and Mesomorphic Characterisation of Coumarin-Schiff Base and Carboxylate Molecules

Published: Jan. 1, 2024

Language: Английский

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