Details

Autor(en) / Beteiligte

• Abdelrahman, Aya M.
• Ahmed, Nagwa H. S.
• Fahmi, Abdelgwad A.
• Saad, Gamal R.
• Naoum, Magdi M.

Titel

Synthesis and mesophase behaviour of four-ring azo-ester-azo compounds bearing two-terminal alkoxy groups in different lengths and proportions

Ist Teil von

• Liquid crystals, 2020-09, Vol.47 (12), p.1772-1783

Ort / Verlag

Abingdon: Taylor & Francis

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Taylor & Francis Current Content Access【キャンパス外アクセス可】

Beschreibungen/Notizen

• Twenty four different homologues of the formula 4-alkoxy phenylazo phenyl 4ʹ-(4''-alkoxyphenylazo) benzoates (I m/n) were prepared and investigated for their mesophase behaviour. In these compounds, the length of the terminal alkoxy group attached to the benzoate moiety (n) varies between 8 and 16 carbons, while the length of the other alkoxy group, attached to phenolic portion, varies between 6 and 12 carbons. Their mesophase characteristics were examined via differential scanning calorimetry (DSC) and the type of the phase is identified by polarised light microscopy (PLM). Compounds newly prepared were structurally characterised by infrared, 1 H-NMR, mass spectroscopy, thermogravemetric and elemental analyses. Comparative studies were made between the prepared four-ring compounds and their corresponding previously investigated three-ring azo/ester analogues. The stabilities and mesomorphic ranges of the prepared compounds were found to be significantly higher than their three rings analogues.