An Essential Mass Detection Unit for Laser Spectroscopy of Chiral Aggregates at 0.4 Kelvin

如果一个分子的镜像不能像我们的右手和左手那样叠加在自己身上，那么它就是手性的。由于一对镜像的相似性，在许多情况下，用其镜像替换一个镜像可能对关联系统的属性带来很小或没有变化。然而，在手性识别事件中，当一个手性分子与另一个手性分子或手性光相互作用时，手性的影响可能会很突出，就像人类握手的情况一样(即右/右握手与左/右握手的感觉有多么不同)。化学家面临的另一个挑战是，我们如何区分右手分子和左手分子。一般来说，差异很小，几乎察觉不到。为了提高我们的检测灵敏度，我们需要使用手性传递和放大的伎俩，也就是将手性特征转移到一个更强大的可以将微弱信号放大许多个数量级、检测来自报告者的信号而不是直接从源头来的“报告者”。我们的研究旨在找出“记者”，并评估什么因素，如溶剂和光，影响手性识别/转移/放大事件的细节。这些知识将使我们能够建立具有预测能力的严格的手性识别、转移和放大模型，并开发新的策略来控制这些具有光和其他影响因素的事件。我们开发了一种强大的光谱工具来促进上述研究活动，这是一种混合激光-质谱仪。该仪器使我们能够方便地将手性物质从溶液中喷洒到气相中，将它们储存在0.4K的超流基质中，这是其他方法不易实现的极低温度，并使用激光光谱分析来探测它们的结构，一次一种。这台尖端仪器是我们总部在过去三年里设计和组装的。它具有连续的氦纳米液滴产生和激光操作，不同于世界上唯一由Max Plank研究小组使用脉冲源建造的其他系统。不幸的是，一个重要的仪器部件，一个已有18年历史的四极质谱计单元出现故障，无法修复。我们紧急请求资金来更换这一故障部件。混合激光-质谱仪对HQP的日常研究活动至关重要。要为HQP提供世界级的培训，并确保他们在世界舞台上不断取得成功和竞争力，让这一工具重新启动和运行是至关重要的。拟议的研究结果将对化学、物理和生物学中手性起重要作用的许多子领域具有价值。所获得的基础知识将对开发从用于制药过程的传感器到用于手性药物合成的新型催化剂等广泛的手性技术具有重要意义。

A molecule is chiral if its mirror image cannot be superimposed onto itself, just like our right and left hands. Because of the similarity of a pair of mirror images, replacing one with its mirror image, may, in many instances, introduce little or no change in the properties of the associated system. In a chirality recognition event, when a chiral molecule interacts with another chiral molecule or chiral light, however, the effect of chirality can be prominent, just as in the case of a human handshake (i.e. how different a right/right versus a left/right handshake feels). A further challenge to a chemist is how we can tell apart the right- versus the left-handed molecules. Generally, the difference is quite small, barely detectable. To improve our detection sensitivity, we need to use the tricks of chirality transfer and amplification, that is to transfer the chirality signature to a much stronger "reporter" who can amplify the feeble signal by many orders of magnitude and detect the signal from the reporter rather than directly from the source. Our research aims to identify "reporters" and evaluate what factors, such as solvent and light, influence chirality recognition/transfer/amplification events in great detail. Such knowledge will allow us to formulate rigorous chirality recognition, transfer, and amplification models with predictive power and to develop new strategies to control these events with light and other influencing factors. One powerful spectroscopic tool we have developed to facilitate our research activities described above is a hybrid laser-mass spectrometer. This instrument enables us to spray chiral species from solution into the gas phase conveniently, store them in a superfluid matrix at 0.4 K, an extremely low temperature not easily achieved by other means, and use laser spectroscopy to probe their structures one species at a time. This leading-edge instrument was designed and assembled by our HQP in the past three years. It features continuous helium nanodroplet generation and laser operation, different from the only other system in the world built by a Max Plank research group which uses a pulsed source. Unfortunately, one important instrument component, an 18-year-old quadrupole mass spectrometer unit, failed and cannot be repaired. We request funding to replace this failed component urgently. The hybrid laser-mass spectrometer is crucial for HQP's daily research activities. To get the instrument up and running again is of utmost importance in offering world-class training to HQP, and in ensuring their continuous success and competitiveness on the world stage. The outcome of the proposed research will be valuable to many subfields in chemistry, physics, and biology where chirality plays a significant role. The fundamental knowledge gained will be important for developing a broad range of chiral technologies from sensors for pharmaceutical processes to novel catalysts for chiral drug syntheses.