Stabilization of encounter complexes of intermolecular frustrated Lewis pairs by dispersion energy donors

通过色散能量供体稳定分子间受阻路易斯对的相遇复合物

• 批准号: 397983120
• 负责人: Professor Dr. Jan Paradies
• 金额: --
• 依托单位: Mulliken Center for Theoretical Chemistry
• 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/397983120?language=en
• 关键词: Stabilization; encounter; complexes; intermolecular; frustrated

Dispersion interactions have now been identified in all fields of chemical research giving rise to unusual physical properties, conformations, selectivity of reactions and stabilization of overcrowded molecules. One of the most fascinating aspects is that steric bulk in the form of dispersion energy donors can also lead to the thermodynamic stabilization of molecules resulting in spectacular bonding situations or in extremely short intermolecular distances.This research project focusses on the exploitation of dispersion energy donors for the stabilization of the encounter complexes of intermolecular frustrated Lewis pairs. The triaryl derivatives of phosphorus, nitrogen and boron derived Lewis bases and Lewis acids will be equipped in 3 and 5 position of the aromatic rings with dispersion energy donors. Rigid alkyl fragments such as methyl, isopropyl and tertbutyl will provide the necessary dispersion energy to stabilize the corresponding encounter complex of the Lewis acid and Lewis base. All in all, 54 combinations of dispersion energy stabilized encounter complexes are available, which will be investigated by nuclear-Overhauser enhanced NMR spectroscopic methods. The directionality of the corresponding intermolecular interactions will be analyzed offering the elaboration of solution structures. Furthermore, the association constants will be determined at different temperatures enabling for the determination of the thermodynamic parameters. Furthermore, the activity of the frustrated Lewis pairs in the hydrogen splitting will be investigated connecting dispersion stabilization of the encounter complexes to catalytic activity. The experimental data is of high value for the quantum mechanical description of dispersion interactions offering the improvement of accuracy of dispersion-corrected density functional theory. Our synthetic investigations will be complemented by quantum-mechanical calculations in strong collaboration with S. Grimme. The structure of each of the Lewis acid and Lewis base will be optimized by DFT-based methods and subsequent energy decomposition analysis will specify the role of the various energy contributions. Ultimately, this provides a qualitative and quantitative analysis of interacting dispersion energy donors on a highly systematic level. In summary, this approach to dispersion energy donor-stabilized encounter complexes of Lewis pairs strongly connects to all of the key-topics of the SPP 1807: - synthesis of novel dispersion energy donor -stabilized structure- quantitative evaluation of dispersion energy donors in connection with intermolecular complexation,- solvent dependency of dispersion energy donor-stabilized structures and- transition-state stabilization through dispersion energy donors

分散相互作用现已在化学研究的所有领域中得到确认，它产生了不寻常的物理性质、构象、反应的选择性和过度拥挤分子的稳定性。最令人着迷的一个方面是，以色散能量供体形式存在的立体体也可以导致分子的热力学稳定，从而产生壮观的成键情况或极短的分子间距离。本研究项目的重点是利用色散能量供体来稳定分子间受挫刘易斯对的相遇配合物。磷、氮和硼的三芳基衍生物衍生的路易斯碱和路易斯酸在芳香环的3和5位上具有分散能供体。刚性烷基碎片如甲基、异丙基和叔丁基将提供必要的分散能量来稳定相应的路易斯酸和路易斯碱的相遇配合物。总的来说，54种色散能量稳定的相遇配合物组合是可用的，它们将通过核-奥弗豪瑟增强核磁共振波谱方法进行研究。相应的分子间相互作用的方向性将被分析，提供溶液结构的阐述。此外，将确定在不同温度下的缔合常数，从而确定热力学参数。此外，还将研究遇合物的分散稳定性与催化活性之间的关系。实验数据对色散相互作用的量子力学描述具有较高的价值，提高了色散校正密度泛函理论的精度。我们的综合研究将辅以量子力学计算与S.格里姆的密切合作。每个Lewis酸和Lewis碱的结构将通过基于dft的方法进行优化，随后的能量分解分析将指定各种能量贡献的作用。最终，这在高度系统的水平上提供了相互作用色散能量供体的定性和定量分析。综上所述，这种色散能供体稳定的Lewis对偶遇配合物的方法与SPP 1807的所有关键主题紧密相关：-新型色散能供体稳定结构的合成-与分子间络合有关的色散能供体的定量评估，-色散能供体稳定结构的溶剂依赖性以及-通过色散能供体稳定过渡态