作者:Siân E. Estdale、Roger Brettle、David A. Dunmur、Charles M. Marson
DOI:10.1039/a606139g
日期:——
A new approach to the synthesis of azulene liquid crystals is described
based on Hafner’s procedure involving reaction of a pyridinium salt
with a cyclopentadienide. The preparation of a variety of liquid
crystalline materials using this method is described. Variants are
reported with single substituents on the azulene ring in the 6-position
and doubly substituted in the 2, 6- positions. The effect of the azulene
ring as a core or dipolar terminal structural element is explored.
6-(5-Alkyl-1,3-dioxan-2-yl)azulenes are shown to exhibit smectic A phases
and 2-cyclohexyl-6-(5-tridecyl-1,3-dioxan-2-yl)azulene show smectic A and
B phases. Phase characterisation of the materials is recorded together
with X-ray measurements on the smectic A phase of one representative
compound. Results of dichroism studies on the azulene mesogens are also
briefly reviewed.
介绍了一种合成苊系液晶的新方法,基于Hafner的程序,涉及吡啶盐与环戊二烯阴离子的反应。本文描述了利用这种方法制备多种液晶材料的过程。报道了在苊环的6位单取代和在2,6位双取代的变体。探讨了苊环作为核心或偶极末端结构元素的影响。6-(5-烷基-1,3-二恶烷-2-基)苊被证明具有近晶A相,而2-环己基-6-(5-十三烷基-1,3-二恶烷-2-基)苊显示了近晶A和B相。记录了这些材料的相态特性,并对其中一个代表性化合物的近晶A相进行了X射线测量。还简要回顾了苊类介晶的二向色性研究结果。