Liquid crystal and photoluminescent properties of a series of symmetrical 1,2-bis(4-alkoxybenzylidene)hydrazines bearing long-tails of hydrocarbon chain
| Autor: | Huayna Terraschke, Adil A. Awad, Al-Ameen Bariz OmarAli, Ahmed Jasim M. Al-Karawi, Giscard Doungmo |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
chemistry.chemical_classification
Photoluminescence Bearing (mechanical) Materials science Series (mathematics) 010405 organic chemistry Hydrazine 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences law.invention Crystallography chemistry.chemical_compound Hydrocarbon chemistry Chain (algebraic topology) law Liquid crystal General Materials Science 0210 nano-technology |
| Zdroj: | Liquid Crystals. 48:412-422 |
| ISSN: | 1366-5855 0267-8292 |
| DOI: | 10.1080/02678292.2020.1786175 |
| Popis: | In this work, 1,2-bis[4-(n-alkoxy)benzylidene]hydrazine (n-alkoxy: O(CH2)nH, n = 11–18 or 20), a symmetrical series of azines (linear compounds with rod-like shape structure), were synthesised using a very simple two-step procedure as a part of our continuing effort in evaluating hydrophobic 1,2-disubstituted hydrazine compounds as photoluminescent liquid crystalline materials. The first step of the synthesis involved the alkylation of the OH group of 4-hydroxybenzaldehyde in basic medium using the Williamson method to obtain 4-alkoxybenzaldehydes. While the second step included the condensation reaction of hydrazine hydrate and appropriately 4-alkoxybenzaldehydes compounds (mole ratio 1:2, respectively) in acidic medium under ambient conditions. The prepared compounds were characterised and their structures elucidated depending upon infrared (IR), ultraviolet-visible (UV–Vis), nuclear magnetic resonance (1HNMR, 13CNMR, DEPT NMR, 2D 1H-1H-COSY and 2D 1H-13C- HSQC) and elemental analysis (CHN). Liquid crystalline behaviour and photoluminescent properties were studied using polarised light optical microscopy (POM), fluorescence emissions (FE), differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) techniques. The studies showed that all of these compounds are enantiotropic liquid crystalline materials exhibiting smectic (SmA and SmC) and nematic (droplet and thread) mesophases . The study also displayed that all of the prepared compounds are photoluminescent in the crystalline and liquid crystal states. |
| Databáze: | OpenAIRE |
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