Effect of position of the lateral fluoro substituent on the mesophase behaviour of aryl 4-alkoxyphenylazo benzoates in pure and binary mixtures

Citation:
Ahmed, N. H. S., G. R. Saad, and M. M. Naoum, "Effect of position of the lateral fluoro substituent on the mesophase behaviour of aryl 4-alkoxyphenylazo benzoates in pure and binary mixtures", Liquid Crystals, vol. 45, issue 10, pp. 1487 - 1497, 2018.

Abstract:

Five groups of 4-substituted phenyl 4ʹ-(2ʺ- (or 3″-) substituted-4ʺ-alkoxyphenylazo) benzoates (Ina-c to Vna-c) were investigated in which, within each group, the length of the terminal alkoxy group varies between 8 and 16 carbons, while the other terminal substituent, X, is a polar group that alternatively changed between the electron-donating CH3O and the electron-withdrawing Br group, in addition to the un-substituted analogue (X = H). The lateral substituent (Y) in the five groups I–V varies, respectively, between H, 3-CH3, 2-CH3, 3-F and 2-F. Their mesophase stabilities were determined by differential scanning calorimetry and phases identified by polarised light microscopy. The two newly prepared groups of compounds (IVna-c and Vna-c) are structurally characterised by infrared, 1H-NMR, mass spectroscopy, thermogravimetric and elemental analyses. Binary phase diagrams were constructed for each pair of isomers from groups IV and V bearing the same wing substituents but the lateral F is attached to different positions (2ʺ or 3″). © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.

Notes:

Cited By :1Export Date: 6 March 2019

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