Investigation of London Dispersion Interactions with Azobenzene Switches

伦敦色散与偶氮苯开关相互作用的研究

• 批准号: 397692616
• 负责人: Professor Dr. Hermann A. Wegner
• 金额: --
• 依托单位: Institut für Organische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/397692616?language=en
• 关键词: Investigation; London; Dispersion; Interactions; Azobenzene

The effect of bulky groups has been mainly considered according to their repulsive interactions. Recently, it has been realized, that the attractive part of the van-der-Waals interactions, London dispersion, can be utilized as stabilizing element in molecular and reaction design. Despite the progress made, the nature of these forces are still not fully understood. Especially the experimental evaluation of the strength in terms of dispersion of different groups (dispersion donor groups = DDGs) has only been scarcely addressed. A long disputed issue is the effect of solvation on dispersion. In the past years, we could show that the thermal back reaction of azobenzene from the Z- to the E-isomer is ideally suited to address these questions. It allows positioning two DDGs in close proximity. By examining the isomerization rate, the stability of various DDGs can be assayed based on the Bell-Evans-Polyani relationship. Herein, various DDGs ranging from alkyl to structures relevant in life science, such as peptides, nucleobases, etc. will compared according to their dispersion strength. Furthermore, the influence of different solvents on the dispersion strength of given DDGs will be investigated providing essential guidelines, how to design ideal conditions to make the best use of dispersive interactions. The studies will be completed with collaborative efforts with other groups within the SPP 1807 in the area of catalysis, supramolecular chemistry and structural analysis.

大基团的影响主要是根据它们的排斥相互作用来考虑的。最近，人们认识到，范德华相互作用的有吸引力的部分，即伦敦色散，可以用作分子和反应设计中的稳定元素。尽管取得了进展，但这些力量的性质仍未完全了解。特别是不同基团（分散供体基团= DDG）的分散强度的实验评估几乎没有得到解决。一个长期争议的问题是溶剂化对分散的影响。在过去的几年中，我们可以证明偶氮苯从 Z 异构体到 E 异构体的热逆反应非常适合解决这些问题。它允许将两个 DDG 放置在非常接近的位置。通过检查异构化率，可以根据 Bell-Evans-Polyani 关系来测定各种 DDG 的稳定性。在此，将根据其分散强度对从烷基到生命科学相关结构（例如肽、核碱基等）的各种DDG进行比较。此外，还将研究不同溶剂对给定 DDG 分散强度的影响，为如何设计理想条件以充分利用分散相互作用提供重要指导。这些研究将通过与 SPP 1807 催化、超分子化学和结构分析领域的其他小组的合作完成。