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.

大体积基团的影响主要是根据它们的排斥作用来考虑的。最近，人们已经认识到，范德华相互作用的吸引力部分，伦敦分散，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得到充分了解。特别是在不同基团（分散体供体基团= DDG）的分散方面的强度的实验评价几乎没有得到解决。一个长期有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，热逆反应偶氮苯从Z-到E-异构体是非常适合解决这些问题。它允许将两个DDG定位在非常接近的位置。通过检查异构化速率，可以基于Bell-Evans-Polyani关系来分析各种DDG的稳定性。在此，从烷基到生命科学中相关的结构，例如肽、核碱基等的各种DDG将根据它们的分散强度进行比较。此外，不同溶剂对给定DDG的分散强度的影响将被研究，提供必要的指导方针，如何设计理想的条件，以最好地利用分散相互作用。这些研究将与SPP 1807中催化，超分子化学和结构分析领域的其他小组合作完成。