作为库库比图宏循环的客体:对光反应的结合和热异构的超分子催化
Miriam Colaço1, Julia Ewert2, Jan-Simon von Glasenapp2
1Laboratório Associado para a Química Verde (LAQV), Rede de Química e Tecnologia (REQUIMTE), Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
Journal of the American Chemical Society
|December 25, 2024
概括
研究人员开发了一种新型的宿主-客体系统,使用甲[7]uril和diazocine来逆转光诱导的结合. 这一突破使得光控制的分子功能和超分子光酸成为可能.
科学领域:
- 超分子化学
- 摄影化学
- 分子机器
背景情况:
- 宿主-客群的光交换可以实现像光驱动机器这样的宏观功能.
- 传统系统使用亚博客在暴露于紫外线时结合E异构体和解离Z异构体.
- 现有的系统往往缺乏有效的控制或在光异构化中表现出产品抑制.
研究的目的:
- 引入一种具有反向光稳定的新型甲[7]uril (CB7)/diazocine宿主-客体.
- 研究CB7对二素异构的催化作用.
- 探索库库比图里尔 (CB7和CB8) 对二素异构体的结合选择性,并证明一种超分子光酸的应用.
主要方法:
- 库库比特[7]uril (CB7) /diazocine宿主-客人复合物的合成和特征.
- 在水溶液中确定与CB7和CB8的E和Z异构体的关联常数.
- 用光谱分析研究异构化动力学和CB7催化E → Z异构化的机制.
- 通过利用差异性结合亲和度来证明一个超分子光酸.
主要成果:
- 在紫外线照射下,CB7/diazocine复合体表现出反向稳定性,在黑暗中自我组装和分离.
- 具有CB7的Z和E异构体的关联常数差异超过10^4倍,Z异构体的结合明显较弱.
- CB7显著加速热激活的E → Z异构,作为一种类似酶的催化剂,没有产品抑制.
- 黄瓜[8]uril (CB8) 对两种异构体具有很高的亲和力,对Z异构体具有1000倍的选择性.
- Z同位素与CB8的结合力比CB7强10倍.
- 一种超分子光酸成功地被证明,利用CB7结合的客体的增加基性和E异构体对CB7的高亲和力.
结论:
- 开发的CB7/diazocine系统提供了前所未有的光控制组装和拆卸.
- CB7对客体异构产生了罕见的催化作用,为分子机器提供了新的可能性.
- 由于CB7和CB8对二素异构体具有明显的结合偏好,因此可以进行复杂的超分子应用,包括对光敏感的pH控制.
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