Grant for Exploratory Research: NMR of Reactive Intermedi- ates and Surfaces Using Spin Polarized Xe

Zilm教授获得了一笔探索性研究的资助， 研究从实验物理化学计划， 开发核磁共振方法，利用新的 发现了光学偏振技术， 完美自旋极化的氙-129原子核。 在 原则上，这种极化转移到原子核中， 可以实现固体氙基质中的分子， NMR信号的增强高达四个数量级 大小 这些新的实验预计将有很高的 对检测的影响要小几个数量级 氙基质隔离中的分子浓度。 这 这意味着，反应性物种是在非常 化学反应中的小稳态量可以 用核磁共振检测，提供详细的结构信息。 这也意味着低灵敏度核，如 可以观察到天然丰富的碳-13和硅-29 即使在这种低浓度下。 %%% 这个探索性的研究项目将利用公正的 发现了完全极化核自旋的方法， 氙通过使用氙转移偏振到其他 原子核，从而增强它们的核磁共振谱 以一万倍的速度 初步实验将 确定有效的必要条件， 极化转移氙可以作为固体使用 用于检测极少量活性物质的基质 分子和分子碎片。 氙气也可以放在 在一个表面上，只允许检测表面原子。

Professor Zilm is supported by a grant for exploratory research from the Experimental Physical Chemistry Program to develop the NMR methods which would take advantage of the newly discovered optical polarization techniques for producing nearly perfectly spin-polarized Xe-129 nuclei in xenon gas. In principle, the transfer of this polarization to nuclei in a molecule in a solid xenon matrix can be achieved for enhancement of the NMR signals by up to four orders of magnitude. These novel experiments are expected to have high impact on the detection of orders of magnitude smaller concentrations of molecules in xenon matrix isolation. This would mean that reactive species which are created in very small steady state quantities in a chemical reaction could be detected with NMR, providing detailed structural information. This would also mean that low sensitivity nuclei, such as naturally abundant carbon-13 and silicon-29 could be observed even at these low concentrations. %%% This exploratory research project will make use of the just discovered method of completely polarizing the nuclear spins in xenon by using the xenon to transfer polarization to other nuclei, thus enhancing their nuclear magnetic resonance spectra by ten thousand fold. The preliminary experiments will determine the conditions that are necessary for the efficient polarization transfer. The xenon could be used as a solid matrix for the detection of very small amounts of reactive molecules and molecule fragments. The xenon can also be laid down on a surface to allow the detection of only surface atoms.