Physical Sciences and Mathematics Commons^™

Shape-Persistent V-Shaped Mesogens-Formation Of Nematic Phases With Biaxial Order, Matthias Lehmann, Shin-Woong Kang, Christiane Köhn, Sönke Haseloh, Ute Kolb, Dieter Schollmeyer, Qingbing Wang, Satyendra Kumar

Satyendra Kumar

A homologous series of shape-persistent V-shaped molecules has been designed to form the biaxial nematic phase. Phenyleneethynylene moieties are attached to a bent fluorenone unit to create an apex angle of about 90°, which is determined from the single crystal structure. Two mesogens, one symmetric and another unsymmetric, have been synthesized by attaching a cyano group to one or both of the peripheral phenyl units, respectively. These groups introduce local dipoles essential for the formation of the nematic phases. The tendency to form a crystalline phase is reduced by laterally substituted hexyloxy chains which allow the nematic phase to be …