贝塔-环氧的化对分子结构和纳入复合物的形成的影响:X射线研究
M Añibarro1, K Gessler, I Usón
1Institut für Kristallographie, Freie Universität Berlin, Takustrasse 6, D-14195 Berlin, Germany.
Journal of the American Chemical Society
|November 29, 2001
概括
peracylated beta-cyclodextrins (CDs) 由于乙烯链的硬质阻碍而表现出扭曲的非平面结构. 这种分子内腔的闭合防止了溶液中包含复合物的形成.
科学领域:
- 超分子化学 超分子化学
- 碳水化合物化学 碳水化合物化学
- 晶体学 晶体学是指结晶学.
背景情况:
- Peracylated beta-cyclodextrins (CDs) 是一种经过修改的环氧,在分子封装中具有潜在的应用.
- 了解它们的结构动力学和宿主-客房属性对于设计新的功能材料至关重要.
研究的目的:
- 为了阐明三种 peracylated beta-cyclodextrins 的分子结构: heptakis(2,3,6-tri-O-acetyl) -beta-CD (TA),heptakis(2,3,6-tri-O-propanoyl) -beta-CD (TP),以及heptakis(2,3,6-tri-O-butanoyl) -beta-CD (TB).
- 为了研究这些基化CD与各种客分子的溶液相内置行为.
主要方法:
- 使用单晶X射线结构分析来确定TA,TP和TB的精确三维结构.
- 循环二重化 (CD) 光谱法被用来研究溶液中的纳入复合体形成.
主要成果:
- 化破坏了分子内结,导致圆扭曲和宏观循环中的非平面船形结构.
- 葡萄糖单元采用不同的形状 ((4) C ((1) 椅子或 (O) S ((2) 斜船) 来减轻乙烯链的硬质应变.
- 观察到,乙链在CD腔内分子内自我包含,有效地阻断了腔.
- 溶液中没有形成包含复合物,这归因于乙链诱导的腔腔堵塞.
结论:
- 该研究显示,与原生CD相比, peracylatedβ-cyclodextrins具有显著的结构变化.
- 分子内乙链的含有是限制这些在溶液中修饰的环极素宿主-客的能力的一个关键因素.
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