First carbohydrate liquid crystals of columnar structure
First carbohydrate liquid crystals of columnar structure
复制标题
第一个柱状结构的碳水化合物液晶
DOI：
10.1080/02678298908029077
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发表时间：
1989
期刊：
影响因子：
2.2
通讯作者：
A. Eckert
中科院分区：
文献类型：
--
作者：
K. Praefcke;A. Levelut;B. Kohne;A. Eckert
摘要三脚架结构的醛糖S，S-二烷基缩醛，最近由三个小组大量合成，不表现出热致近晶相，而是一个柱状六方中间相（Hx），我们已经证明了X-射线衍射。在这个中间相的分子组织是一个类似的已知的phasmidic分子。这些不同的多元醇，虽然在立体化学上不同，但仅形成一种类型的氢键盘形多聚体。它的中间相结构是由大约五个分子组成的，这些分子排列在柱子上，骨架是氢桥糖部分，周围是硫代烷基。由于三个6-脱氧糖二硫代缩醛被证明是非热介晶的末端羟基功能是必不可少的这种分子排列，这似乎是不正确的糖链的内部缺失的，因为我们已经发现在一个案例中。
Abstract S, S-Dialkylacetals of aldoses, tripodal in structure and recently synthesized in large numbers by three groups, do not exhibit thermotropically a smectic, but a columnar hexagonal mesophase (Hx) as we have proved by X-ray diffraction. The molecular organization in this mesophase is comparable with a similar one known for phasmidic molecules. These various multiols, although different in stereo-chemistry, form only one type of hydrogen-bonded disc-shaped multimer. Its mesophase structure is made up of about five molecules placed in columns with a skeleton of hydrogen-bridged sugar parts surrounded by thioalkyl groups in the periphery. Since three 6-deoxy sugar dithioacetals were shown to be non-thermomesomorphic the terminal hydroxyl function is essential for this molecular arrangement which seems not to be true for missing ones in the inner part of a sugar chain, as we have found in one case.