...
  • 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 >Monitoring structural transformations in crystals. 12. Course of an intramolecular [4+4] photo-cycloaddition in a crystal
【24h】

Monitoring structural transformations in crystals. 12. Course of an intramolecular [4+4] photo-cycloaddition in a crystal

机译：监测晶体的结构转变。 12.晶体中分子内[4 + 4]光环加成的过程

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

Variations in crystal and molecular structures, brought about by the intramolecular [4 + 4] photocycloaddition of bi(anthracene-9,10-dimethylene), were monitored using X-ray diffraction. The cell volume increased by 0.8% until the reaction was ca 40% complete, and afterwards decreased by 1.6% during the remainder of the photoreaction. The changes of the a and b lattice parameters were correlated with the changes of the molecular shape and packing. The distance between the directly reacting C atoms varied in a manner not observed for other photochemical reactions in crystals. It was constant until ca 20% photoreaction progress, then decreased, and later stabilized from ca 40% photoreaction progress. This phenomenon was explained by interplay between stress resulting from the presence of product molecules and the rigidity of reactant molecules. Changes of the orientation of molecules during the photoreaction were smaller than in the case of other monitored photochemical reactions in crystals owing to similarities in the shape and packing of reactant and product molecules. Weak C-H center dot center dot center dot pi hydrogen bonds exist among reactant molecules in the pure reactant and partly reacted crystals.
机译：使用X射线衍射监测由双（蒽-9，10-二亚甲基）的分子内[4 + 4]光环加成引起的晶体和分子结构的变化。细胞体积增加0.8％，直到反应完成约40％为止，然后在其余的光反应过程中减少1.6％。 a和b晶格参数的变化与分子形状和堆积的变化相关。直接反应的C原子之间的距离以晶体中其他光化学反应未观察到的方式变化。直到约20％的光反应进行之前，它一直是恒定的，然后降低，然后从约40％的光反应进行中稳定下来。这种现象由产物分子的存在所引起的应力与反应物分子的刚性之间的相互作用所解释。由于反应物和产物分子的形状和堆积相似，因此在光反应过程中分子取向的变化小于在晶体中进行其他监测的光化学反应的情况。在纯反应物和部分反应的晶体中的反应物分子之间存在弱的C-H中心点中心点中心点pi氢键。

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