Liquid crystal molecules with an enyne rigid core

New mesogens are always a source of interest, especially when they possess a non‐conventional architecture. In this article are presented the synthesis and polymorphism of a series of compounds possessing a 1,4‐diaryl‐1‐buten‐3‐yne moiety as the rigid core with an alkoxy chain on each side. Such a core is termed an enyne core. The alkoxy chain is lengthened on each side of the enyne core according to two different fashions: symmetrically and asymmetrically. In this way a rich polymorphism is achieved in some compounds. At lower chain length, the compounds exhibit smectic H and nematic phases where cybotactic groups are observed in X‐ray diffraction patterns. As the alkoxy chains extend, smectic C and smectic F phases appear. The non‐cylindrical shape of these compounds involves a molecular packing that is preserved throughout the polymorphism. A comparison between symmetric and asymmetric compounds, from X‐ray diffraction pattern analysis of their smectic H phases, reveals a parallel molecular stacking. It also discloses the importance of the moiety that is lengthened since different polymorphisms are obtained.