一个自发的单晶到单晶的多态过渡,涉及主要的包装变化
Baiju P Krishnan1, Kana M Sureshan
1School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Kerala 695016, India.
Journal of the American Chemical Society
|January 14, 2015
概括
这项研究揭示了4,6-O-乙烯-α-d-galactosyl azide的两个不同的晶体形式 (多态). 这些多态体以一种令人惊的单晶到单晶的方式相互转变,影响它们的热行为.
科学领域:
- 晶体学 晶体学是指结晶学.
- 固态化学 固态化学
- 碳水化合物的化学成分
背景情况:
- 多态性,固体材料以多种晶体形式存在的能力,在材料科学和制药方面至关重要.
- 了解多态转换的条件和机制对于控制材料性质至关重要.
研究的目的:
- 为了研究4,6-O-乙烯-α-d-银酸的结晶行为和多态性.
- 阐明不同晶体形式之间的多态过渡的机制和条件.
主要方法:
- 单晶X射线衍射 (SCXRD) 用于结构分析.
- 差分扫描热量计 (DSC) 用于热分析.
- 可变温度粉末X射线衍射 (PXVT) 用于现场过渡监测.
- 极化光显微镜 (PLM) 用于观察过渡动态.
主要成果:
- 确定了4,6-O-乙烯-α-d-银酸的两个不同的多态 (α和β),不同的晶体习惯和空间组 (单临床P21与三临床P1).
- 多态α在化之前经历了不可逆转的内热过渡到多态β,这解释了它们类似的观察到的点.
- 过渡通过单晶到单晶 (SCSC) 机制发生,既是热诱导的,又是在室温下自发的,通过PLM观察到核和生长.
结论:
- 溶剂依赖的结晶导致具有显著结构差异的明显多态.
- 观察到的SCSC过渡机制,尽管有结构上的差异,但突出了独特的固态转换路径.
- 这些发现为控制晶体形式和理解碳水化合物衍生物的固态反应提供了洞察力.
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