Gas Phase Supramolecular Characterization

在化学测量和成像项目的支持下，杨百翰大学的David Dearden教授和他的团队正在设计新的方法来检测和表征基于南瓜形状的分子装置的原型(南瓜形状的分子)构成了一些最小的可能的容器。正在开发的方法通过提供更好的灵敏度来补充现有技术。其中包括对这些材料的第一次红外多光子解离研究，基本上是使用红外激光拍摄“快照”，揭示这些设备组装在一起的方式。其他实验室正在研究葫芦和相关的“容器”，以期在分子机器的部件、药物的包装、保护和输送以及灵敏的新分析分析中有潜在的应用，如直接检测血液中的胰岛素水平(与糖尿病的检测和治疗有关)。人们普遍认为，瓜环的结合性质对溶剂和反离子是敏感的，但这种依赖的原因还不清楚。因此，在没有溶剂和反离子的情况下，这些基本的气相结构研究对于获得促进未来应用所需的理解至关重要，解决的问题包括：捕获分子在空腔内如何影响边缘上的阳离子结合，结合/捕获物种的交换机制，以及捕获的客体酸度发生巨大变化的原因。正在开发的表征方法将使这种最终可能影响制造、计算和医学的超分子化学的应用成为可能。这些技术也将立即对涉及自然界的“分子机器”--蛋白质--的生物分子研究有用。这项工作还将带来重要的教育效益。研究生将接受高性能质谱学先进技术方面的培训，这些技术对生物技术产业和新兴的蛋白质组学领域至关重要。一个类似的目标是吸引有才华的本科生从事化学研究。为了实现这一目标，所支持的仪器也被用于分析和物理化学的本科课程，提供了大多数学生在研究生院以外看不到的先进技术的直接经验。

With support from the Chemical Measurement and Imaging program, Prof. David Dearden and his group at Brigham Young University are devising new approaches to the detection and characterization of prototypical molecular devices based on pumpkin-shaped molecules (named cucurbiturils, after the Latin name for "pumpkin") that constitute some of the smallest possible containers. The methods being developed complement existing techniques by providing better sensitivity. They include the first infrared multiphoton dissociation studies of these materials, essentially using infrared laser light to take "snapshots" that reveal the way the devices fit together. Cucurbiturils and related "containers" are being investigated in other laboratories for potential applications in such diverse areas as components of molecular machines; in drug encapsulation, protection, and delivery; and in sensitive new analytical assays such as the direct detection of insulin levels in the blood (relevant to the detection and treatment of diabetes). It is widely recognized that the binding properties of cucurbiturils are sensitively dependent on solvents and counterions, yet the reasons for this dependence are not clearly understood. Hence, these fundamental gas-phase studies of structures in the absence of solvent and counterions are vital to gain understanding needed to facilitate future applications, addressing questions such as how trapping molecules inside the cavity affects the binding of cations on the rims, the mechanism of exchange of bound/trapped species, and the origin of the large shifts in acidity that occur for trapped guests.The characterization methods being developed will enable applications of this "supramolecular" chemistry that may ultimately impact manufacturing, computing, and medicine. The techniques will also be immediately useful to biomolecular studies involving nature's "molecular machines," proteins. The work will also have important educational benefits. Graduate students will be trained in advanced techniques for high performance mass spectrometry that are vital for the biotechnology industry and the emerging field of proteomics. A parallel aim is to attract talented undergraduate students to chemical research. Toward this aim, the instrumentation supported is also used in undergraduate courses in analytical and physical chemistry, providing direct experience with advanced techniques most students would not otherwise see outside of graduate school.