Chiral Molecular Beams, Quantum Tunneling and Improved Microwave Spectroscopy

手性分子束、量子隧道和改进的微波光谱

• 批准号: 1506868
• 负责人: John Doyle
• 金额: $ 45万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1506868&HistoricalAwards=false
• 关键词: Chiral; Molecular; Beams; Quantum; Tunneling

With this award, the Chemical Measurement and Imaging Program of the Division of Chemistry is supporting Professor John Doyle of Harvard University to study molecular chirality through advances in molecular beam techniques and interrogation with microwave spectroscopy. Atoms and molecules are the basic building blocks of all substances. Understanding their essential behavior is necessary for a full understanding of chemical processes, including those underlying living systems. In living cells, many molecules have a fundamental 'twist', very similar to the direction of spiral ridges on a screw. Just like a screw, the direction of the molecular spiral, known as 'chirality', determines function. For normal screws ('right handed' ones), if you turn them clockwise they tighten; a 'left handed' screw would loosen. This is a very pronounced effect in molecules also. For example, many new drugs have a single handedness (i.e. chirality). In order to understand the basic behavior of molecules, their chirality must be detectable. In this project researchers will use their newly discovered tool for measuring chirality to study fundamental quantum behavior of chirality in molecules. In particular, they will look for the slow transformation of a molecule with a spiral in one direction to a molecule with a spiral in the opposite direction. This effect can only be described by the fundamental theory of the microscopic realm, quantum mechanics. Researchers in the Doyle group will test these predictions and in carrying out these studies gain valuable experience in modern physical and analytical chemistry research.In order to study chirality of molecules, the Doyle group will use molecular beams and interrogate these with microwave radiation. The molecular seams will be generated by injecting them through a small hole into a nearly perfect vacuum. This will form a stream of molecules that have no interactions 'a nearly pristine physical setup' except with the applied electromagnetic radiation. The molecules that will be studied have electric dipoles (similar to a bar magnet, except with electric charge on the North and South poles). These dipoles will absorb and emit radiation in the microwave regime. By creating a screw-type pattern of microwave radiation, the molecule can be caused to emit radiation that depends on the direction of the spiral (chirality) of the molecules. This is similar to testing if a screw is left or right handed by trying to insert it in a right-handed screw hole. The researchers will initially prepare molecules of one chirality (e.g. right handed) and then use microwaves to see if they transform into the other chirality (left-handed). Comparison with theory will be done to test our understanding of this fundamental phenomenon.

通过此奖项，化学划分的化学测量和成像计划支持哈佛大学的约翰·道尔教授通过分子束技术的进步研究分子手性，并通过微波光谱学询问。 原子和分子是所有物质的基本基础。了解其基本行为对于对化学过程（包括基本生活系统）的完全理解是必要的。在活细胞中，许多分子具有基本的“扭曲”，与螺钉上的螺旋脊方向非常相似。就像螺钉一样，分子螺旋的方向（称为“手性”）决定了功能。对于普通螺钉（“右手”），如果您顺时针旋转它们，则它们会拧紧； “左手”螺钉将松动。这在分子中也非常明显。例如，许多新药具有单手（即手性）。为了了解分子的基本行为，必须检测到它们的手性。在这个项目中，研究人员将使用其新发现的工具来测量手性，以研究分子手性的基本量子行为。特别是，他们将寻找一个在一个方向上螺旋形向相反方向的分子的分子的缓慢转化。这种效果只能通过微观领域的基本理论来描述量子力学。 Doyle组的研究人员将测试这些预测，并在进行这些研究时获得了现代物理和分析化学研究的宝贵经验。为了研究分子的手性，Doyle组将使用分子束并使用微波辐射来询问这些束。分子接缝将通过将它们通过一个小孔注入几乎完美的真空来产生。这将形成一系列没有相互作用的分子流，除了与施加的电磁辐射不同之外。将研究的分子带有电偶极子（类似于磁铁，除了北极和南极电荷外）。这些偶极子将在微波状态下吸收并发射辐射。通过创建微波辐射的螺钉型模式，可以使分子发射辐射，该辐射取决于分子的螺旋（手性）方向。这类似于测试是否通过试图将其插入右手螺钉孔中的左或右手。研究人员最初将准备一种手性的分子（例如右手），然后使用微波来查看它们是否转化为其他手性（左手）。将与理论进行比较，以测试我们对这一基本现象的理解。