基于酸的旋转开关中的异构化机制:横向移动,旋转或分体化?
Shainaz M Landge1, Ekatarina Tkatchouk, Diego Benítez
1Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, USA.
化学控制的arylhydrazone分子开关可逆地在E和Z配置之间切换. 异构化可能是通过围绕C-N单键旋转而发生的,而不是C=N双键旋转.
科学领域:
- 有机化学 有机化学
- 超分子化学 超分子化学
- 摄影化学的使用.
背景情况:
- 具有分子内键的基素化合物作为分子开关.
- 这些开关表现出可逆的E/Z同质化.
- 了解异构化机制对于设计先进的分子装置至关重要.
研究的目的:
- 为了合成和描述新型的阿里化分子开关.
- 研究由化学刺激诱导的E/Z异构的机制.
- 阐明溶剂极性和过渡状态在异构化过程中的作用.
主要方法:
- 合成与分子内有键的化分子开关.
- 使用酸和进行E/Z异构的化学诱导.
- 动力学研究分析溶剂极性对异构化速率的影响.
- 使用密度函数理论 (DFT) 和自然键轨道 (NBO) 方法进行计算分析.
主要成果:
- 对于合成的阿里化开关,已经证明了完全和可逆的E/Z切换.
- 用三酸激发的质子化诱导切换到Z-H(+) 配置.
- 动力数据表明一个极化,有组织的过渡状态,有利于旋转机制.
- 据DFT和NBO分析显示,首选的途径是酸-酸盐复合体化,然后是C-N单键旋转.
结论:
- 合成的arylhydrazone开关表现出高效和可逆的E/Z同质化.
- 同体化是由化学刺激驱动的,涉及一个极化过渡状态.
- 主要的异构化途径涉及酸-酸同构化和C-N单键旋转.
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