Creating, imaging, and controlling dynamic chirality induced by molecular rotations

创建、成像和控制由分子旋转引起的动态手性

• 批准号: 411044754
• 负责人: Dr. Sebastian Trippel
• 金额: --
• 依托单位: Controlled Molecule Imaging Group
• 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 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/411044754?language=en
• 关键词: Creating; imaging; controlling; dynamic; chirality

Chirality is ubiquitous throughout nature and is conventionally associated with a chemical or optical activity of a molecule in either of its two enantiomeric (mirror-image) forms. Since its discovery by Louis Pasteur in 1848, there remain many open questions about the origin of chirality. Notably, the origin of biomolecular (homo)chirality, which is concerned with the bias in the chemistry of life that favours L amino acids and D monosaccharides over the other enantiomeric form, is a controversial and often debated subject.Although usually regarded as a geometric property, chirality can also be dynamically created in “statically” non-chiral molecules through extreme rotational excitation [see A. Owens, A. Yachmenev, and J. Küpper, arXiv:1802.07803 [physics.chem-ph], (2018)].The phenomenon of rotationally induced chirality is closely connected to the effect of rotational energy clustering exhibiting by some polyatomic molecules, such as H2S or PH3, at high rotational excitation.In this project we will perform a joint experimental and theoretical investigation to demonstrate for the first time the effect of rotationally-induced chirality: An optical centrifuge rotationally excites the H2S (CH3D, CH4) molecule into chiral cluster states that correspond to clockwise (R-enantiomer) or anticlockwise (S-enantiomer) rotation about axes almost coinciding with single S—H (C—H) bonds. Application of a strong dc electric field during the centrifuge pulse favours one rotating enantiomeric form over the other, creating dynamically chiral molecules with permanently oriented rotational angular momentum. In the course of this project, we will comprehensively investigate all aspects of dynamic chirality induced by extreme rotational excitations, from creating and imaging through to controlling of its properties.This novel and unexplored research topic promises to offer fresh insights into the phenomenon of rotationally induced chirality in molecular systems. Given the importance of chirality to our understanding of molecular and material behaviour, the ability to create chirality in achiral systems is of great practical interest. On a fundamental level, an improved theoretical understanding of molecular chirality will contribute to our basic knowledge of physical, chemical, and biological processes.

手性在自然界中普遍存在，通常与分子的两种对映体（镜像）形式中的任一种的化学或光学活性相关。自从路易斯·巴斯德在1848年发现手性以来，关于手性的起源仍然存在许多悬而未决的问题。值得注意的是，生物分子（同）手性的起源，这与生命化学中的偏向有关，这种偏向有利于L氨基酸和D单糖，而不是其他对映体形式，这是一个有争议和经常争论的主题。虽然通常被认为是一种几何性质，手性也可以通过极端的旋转激发在“静态”非手性分子中动态产生[见A. Owens，A. Yachmenev，and J. Küpper，arXiv：1802.07803 [physics.chem-ph]，（2018）]。旋转诱导手性的现象与一些多原子分子（如H2S或PH 3）在高旋转激发下表现出的旋转能量聚集效应密切相关。在这个项目中，我们将进行联合实验和理论研究，以首次证明旋转诱导手性的效应：光学离心机旋转激发H2S（CH 3D，CH 4）分子转化为手性簇合物状态，其对应于围绕几乎与单个S-H（C-H）键一致的轴的顺时针（R-对映体）或逆时针（S-对映体）旋转。在离心脉冲过程中施加强直流电场有利于一种旋转对映体形式，从而产生具有永久定向旋转角动量的动态手性分子。在这个项目中，我们将全面研究极端旋转激发诱导的动态手性的各个方面，从产生和成像到控制其性质，这一新颖的和未探索的研究课题有望为分子系统中的旋转诱导手性现象提供新的见解。鉴于手性对我们理解分子和材料行为的重要性，在非手性体系中产生手性的能力具有很大的实际意义。从根本上讲，对分子手性的理论理解的提高将有助于我们对物理，化学和生物过程的基础知识。