Chiral catalysis with hybrid plasmonic nanoparticles

胶体粒子由于具有很强的手性光学效应和较高的催化活性，在手性催化领域有着巨大的应用潜力。然而，它们的关键问题之一是纳米颗粒的结构手性特征与有机基底之间的尺度不匹配。到目前为止，催化剂的结构手性特征的大小-形成所谓的手性体-需要与最终产物的大小相匹配，以赋予手性。该提议旨在建立一种基于分散体中的混合等离子体纳米粒子的新型手性催化剂。所提出的催化剂将能够通过经由等离子体激元场增强而不是通过匹配结构手性来转移所需的手性偏置来进行不对称C-C偶联反应，这形成了空间本体。基于这一机理，通过改变简单可逆的手性配体的交换或改变激发光的手性，可以实现催化不对称反应的正交性。此外，通过利用等离子体激元，避免了匹配手性体的需要，因此，产生了广泛的可靶向分子，其特征在于轴向和立体手性。为此目的，将混合纳米颗粒系统设计成将联合收割机结合银纳米颗粒的上级等离子质量与铂族金属的催化活性。因此，等离子体激元不仅将手性赋予基底，而且由于设想的核-壳颗粒设计而通过其强电场增强来促进催化反应。在该项目的所有阶段，实验工作将通过电磁模拟的电场和手性性质的建模来预测和支持，旨在获得合理的合成方法。

Colloidal particles hold great potential for chiral catalysis due to their strong chiroptical effects and high catalytic activity. However, one of their key problems is the mismatch of scales between structural chiral features of the nanoparticles and the organic substrate. So far, the size of the structural chiral features of the catalyst—forming a so-called chiral bulk—needs to match to the size of the final product in order to to confer the chirality. This proposal aims at establishing a novel chiral catalyst based on hybrid plasmonic nanoparticles in dispersion. The proposed catalyst will be able to perform asymmetric C-C coupling reactions by transferring the required chiral bias via plasmonic field enhancement rather than by matching structural chirality, which is forming a steric bulk. Based on this mechanism, orthogonality in the catalytic asymmetric reaction can be achieved via altering of simple and reversible triggers—namely, the exchange of the chiral ligand or by changing the handedness of the exciting chiral light. Additionally, by exploiting plasmonics, the need of a matching chiral bulk is avoided, hence, giving rise to a broad range of targetable molecules featuring both, axial and stereogenic chirality. For this purpose, the hybrid nanoparticle system will be designed to combine the superior plasmonic quality of silver nanoparticles with the catalytic activity of platinum group metals. Thus, the plasmonics will not only confer the chirality to the substrate, but also boost the catalytic reaction by its strong electric field enhancement due to the envisioned core-shell particle design. During all stages of the project, the experimental work will be predicted and supported by modeling of electric fields and chiral properties via electro¬magnetic simulations aiming for a rational synthetic approach.