...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Acta Crystallographica, Section B. Structural Science >Variable-temperature crystal structure studies of m-nitroaniline
【24h】

Variable-temperature crystal structure studies of m-nitroaniline

机译：间硝基苯胺的变温晶体结构研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The crystal structure of m-nitroaniline has been examined at several temperatures over the 90-350 K range. Thermal evolution of the lattice parameters reveals a weak anomaly at 110 K and an important one at 300 K. The thermal expansion coefficients have been calculated at several temperatures and the principal axes cross-sections of the tensor were drawn. The lattice contraction along the b axis direction has been observed. The rigid-body analysis including an attached rigid group has provided the values of the translation and libration tensors at temperatures studied. The results indicate that m-nitroaniline undergoes a glass transition around 130 K arising from freezing molecular librations and translations. From above 340 K the growing plasticity of the m-nitroaniline crystal results in the loss of X-ray diffraction reflections. This is probably a second-order phase transition. It is coupled with a considerable increase in the nitro group torsion amplitude, but the NH . . .O hydrogen bonds are preserved. Analysis of the temperature evolution of short intermolecular distances enabled us to consider the occurrence of reorienting aggregates of hydrogen-bonded molecules in the high-temperature plastic phase. [References: 34]
机译：已经在90-350 K范围内的几个温度下检测了间硝基苯胺的晶体结构。晶格参数的热演化在110 K处显示出一个异常异常，而在300 K时则显示出一个重要异常。已经在几个温度下计算出了热膨胀系数，并绘制了张量的主轴横截面。已经观察到沿b轴方向的晶格收缩。包括附加的刚性基团的刚体分析提供了在研究温度下的平移和自由张量的值。结果表明，间硝基苯胺经历了约130 K的玻璃化转变，这是由冻结的分子释放和翻译引起的。从340 K以上开始，间硝基苯胺晶体的可塑性提高，导致X射线衍射反射的损失。这可能是二阶相变。它伴随着硝基基团扭转幅度的显着增加，但是NH。 。氢键被保留。对短分子间距离的温度演化的分析使我们能够考虑在高温塑性相中氢键结合分子的聚集体发生重新取向。 [参考：34]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号