Achiral non-branched rod-shaped liquid crystals showing anticlinic smectic phase

Both peripheral ends of some straight-shaped mesogenic compounds, possessing a biphenyl or azobenzene moiety as the central rigid core, were systematically modified, and the effect on the liquid-crystalline properties investigated. Introduction of phenyl rings into the middle of the flexible chains was found to produce a well-defined smectic layered structure. Further introduction of another phenyl ring at each terminal end of the peripheral chain had a significant effect on the determination of the molecular tilt direction in the smectic phase, i.e., synclinic or anticlinic. Thus, novel molecular architecture for stabilizing the anticlinic smectic phase was introduced and the origin of the anticlinic ordering discussed.