Grant for Exploratory Research: Laser NMR Spectroscopy

沃伦教授得到了实验物理化学计划的探索性研究拨款的支持，以开发利用一种新观察到的现象的方法，在这种现象中，用圆偏振光照射样品会导致手性分子的核磁共振谱线发生频率移动。由于每个核磁共振核，取决于它相对于生色团的位置，将经历不同的频移符号和幅度，这种现象有可能在拥挤的光谱中区分位于发色团附近的质子。可以消除大多数非手性分子的所有信号，以便通过对左圆偏振光和右圆偏振光进行不同光谱来观察少数手性物种。由于许多重要的分子具有光学活性，这种现象可能会有非常强大的应用。有可能将这项技术结合到复杂系统的多维核磁共振波谱中，同时在一维上打开激光。这个探索性的研究项目将利用刚刚发现的对原子核的核磁共振信号的影响，这些原子核位于具有左旋性(光学活性)的分子的发色团附近。在使用激光用圆偏振可见光照射时。完全消除来自样品中所有其他非光学活性分子的核磁共振光谱中的所有信号是可能的。如果成功，这项技术可能会对含有生物分子的样品的核磁共振光谱产生重大影响。

Professor Warren is supported by a grant for exploratory research from the Experimental Physical Chemistry Program to develop the methods that will take advantage of a newly observed phenomenon in which irradiation of samples with circularly polarized light causes frequency shifts in the NMR spectral lines of a chiral molecule. Since each NMR nucleus, depending on its location relative to the chromophore, will experience a different sign and magnitude of frequency shift, this phenomenon has the potential of being able to distinguish among the protons located close to the chromophore in a congested spectrum. It is possible to eliminate all signals from achiral molecules in the majority, in order to observe minority chiral species by taking a difference spectrum for left vs. right circularly polarized light. Since many important molecules are optically active, this phenomenon could have very powerful applications. There are possibilities of incorporating this technique into multidimensional NMR spectroscopy of complex systems, with the laser on in one dimension. %%% This exploratory research project will make use of the just discovered effect on the nuclear magnetic resonance (NMR) signals of nuclei that are located close to the chromophore group of a molecule possessing handedness (optically active) upon irradiation with circularly polarized visible light using a laser. It is possible to eliminate entirely all signals in the NMR spectrum from all other non-optically active molecules in the sample. If successful, this technique could have a great impact on the NMR spectroscopy of samples containing biological molecules.