Intra- and intermolecular dispersion forces: Understanding complex formation, aggregation, and the effect of solvation using a bottom-up approach

该研究计划的目标是通过使用高分辨率旋转光谱学系统地探索模型系统，显著提高当前对色散相互作用在分子识别和分子结构中的作用的理解。我们将继续我们在光谱研究和表征气相分子体系方面的成功工作，以了解和量化分子内和分子间的相互作用。在自下而上的方法中，我们将研究与理解分子聚集相关的基本过程，最终研究从气体到体相的转变，以及溶剂化对色散的影响。对于第二个资助期，我们现在可以建立一个由合成、光谱和理论化学小组组成的坚实、富有成果和创造性的网络，如上所述。我们建议在以下几个方面做工作：在项目1中，我们的目标是进一步定性和定量地研究各种分子络合物的分散作用。我们将继续我们在乙醚-醇络合物方面的工作(这在第一个资助期已经带来了一些惊喜)，并与我们的伙伴小组合作，将其扩展到酮-醇络合物以及手性物种。在第二个项目中，我们将研究分子的聚集，例如那些具有扩展的π系统的分子，从而在分子水平上探索从单个分子到整体分子的转变。在逐个分子堆积机制上的预期结果也将对与燃烧相关的烟尘颗粒的形成以及与天体化学相关的尘埃颗粒的形成感兴趣。在项目3中，我们将研究溶剂化如何影响分散。我们将研究分子络合物，如二苯醚-甲醇，并研究络合物的逐步溶剂化如何调节团簇形成时的结构偏好。分子射流中的受控条件非常适合于这样的实验。我们的目标是了解溶剂化效应如何依赖于不同的分子体系，以及如何预测和最终控制这一点。

The goal of the research program is to significantly advance the current understanding of the role of dispersion interaction in molecular recognition and intramolecular structures by systematically exploring model systems using high-resolution rotational spectroscopy. We will continue our successful work on spectroscopically investigating and characterizing molecular systems in the gas phase to understand and quantify intra- and intermolecular interactions. In a bottom-up approach, we will study basic processes relevant for understanding molecular aggregation and finally the transition from the gas to the bulk phase, as well as the influence of solvation on dispersion. For the second funding period, we can now build on a solid, fruitful, and creative network of synthesis, spectroscopy, and theoretical chemistry groups, as described above. We propose to work on the following aspects:In project 1, it is our goal to further investigate qualitatively and quantitatively the role of dispersion for a variety of molecular complexes. We will continue our work on ether-alcohol complexes (which already let to a number of surprises in the first funding period) and extend it to ketone-alcohol complexes as well as chiral species, in collaboration with our partner groups. We aim at gaining a complete understanding of how dispersion contributions influence the structures of complexes and which role conformational flexibility plays.In a second project, we will study aggregation of molecules, such as those with extended π systems, and we will thus explore the transition from individual molecules to the bulk on the molecular level. The anticipated results on a molecule-by-molecule build-up mechanism will also be of interest for the formation of soot particles as relevant for combustion as well as of dust grains as relevant for astrochemistry.In project 3, we will investigate how dispersion is influenced by solvation. We will study molecular complexes, such as diphenylether-methanol, and investigate how structural preferences upon clusters formation are modulated by stepwise solvation of the complex. The controlled conditions in a molecular jet are ideally suited for such experiments. We aim at understanding how the effect of solvation depends on the different molecule systems, and how this can be predicted and finally controlled.