Liquid crystal is an intermediate phase between the crystalline solid and an isotropic liquid, a very common substance in our daily lives. Two major classes of liquid crystal are lyotropic, where a liquid crystal is dissolved in a specific solvent under a particular concentration and thermotropic, which can be observed under temperature difference. This review aims to understand how a structure of a certain azo compound might influence the liquid crystal properties. A few factors influence the formation of different liquid crystals: the length of the alkyl terminal chain, inter/intra-molecular interaction, presence of spacer, spacer length, polarization effects, odd-even effects, and the presence of an electron-withdrawing group or an electron-donating group. As final observations, we show the compound’s different factors, the other liquid crystal is exhibited, and the structure–property relationship is explained. Liquid crystal technology is an ideal system to be applied to products to maximize their use, especially in the electronic and medical areas.

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Over the last decades, liquid crystalline has been of great recent importance due to many unique and different features. The linking unit, terminal group, and core system are the most factors to influence the liquid crystal behaviour. Schiff base linkage with the formula of -C=N- can maintain linearity by providing the stepped core structure with high stability. Incorporation of Schiff base linkage in cyclotriphosphazene system enhances the mesophase characteristic and high thermal stability. This review focussed on the mesophase behaviour and physical properties of cyclotriphosphaze derivatives attached to Schiff base linkages. A basic introduction to liquid crystalline materials, including description and classification, is provided in this review.