Collaborative Research: DNP-Enhanced Nuclear-Spin Optical-Rotation Spectroscopy

CHE-1404529和CHE-1404548：合作研究：DNP增强的核自旋光学旋转光谱学在这个由化学部化学测量和成像计划资助的项目中，新墨西哥州联合体的伊戈尔·萨武科夫博士和德克萨斯农工大学的克里斯蒂安·B·希尔蒂教授正在合作开发核自旋光学旋转方法，以提高光学和核磁共振光谱学的信息含量。该技术通过动态矢量极化率将原子核的自旋态和电子结构联系起来。对于有意义的应用来说，严重的障碍是测量的影响通常非常小，需要大量的时间进行检测，即使在质子浓度非常高的水中也是如此。核自旋旋光在化学中的应用进展很大程度上取决于信号增强策略。与现有方法相比，在稀薄样品或多峰样品中的光谱应用还需要很大的改进。在这里，动态核极化被用来产生非平衡核自旋态。超极化样品可以使核自旋旋光信号增加100-100,000倍，这取决于原子核和实验条件，并使该方法能够应用于各种化合物的表征。这项新的光谱技术分三个步骤进行开发。首先，论证了动态核极化超极化样品的核自旋旋光。其次，对各种以前不能接触到的核和分子的增强效应进行了表征，并将结果与理论进行了比较。第三，将该技术应用于染料分子的电子结构表征。从长远来看，这种新光谱的实现为液体中光-物质相互作用的基础研究提供了一种强有力的分析方法。分子的基态和激发态的电子结构决定了它的基本分子性质和反应性。对电子结构的测量对于了解分子在化学反应和其他相互作用中的行为是必要的。在这个项目中，正在开发一种新型的光谱学，它独特地适合于探测电子的空间局域激发态组态。这种光谱是基于对光信号的测量，该光信号通过最近发现的核自旋旋光效应与分子中的特定原子相关联。该项目包括通过新墨西哥州财团和德克萨斯农工大学之间的合作开展的教育活动。职业生涯早期的科学家，包括研究生和本科生，正在接受指导，这项研究的结果被纳入课堂。

CHE-1404529 and CHE-1404548: Collaborative Research: DNP-Enhanced Nuclear-Spin Optical-Rotation SpectroscopyIn this project funded by the Chemical Measurement and Imaging Program of the Chemistry Division, Dr. Igor Savukov of the New Mexico Consortium and Professor Christian B. Hilty of Texas A & M University are collaboratively developing nuclear-spin optical rotation methodology for enhancing the information content in optical and nuclear magnetic resonance spectroscopy. The technique correlates nuclear spin states and electronic structure through dynamic vector polarizability. The severe obstacle for meaningful application is that the measured effect is normally extremely small, requiring substantial time for detection, even in water with very large concentration of protons. Progress in the application of nuclear-spin optical rotation to chemistry critically depends on strategies for signal enhancement. Compared to current methods, large improvements are needed for spectroscopy applications in dilute samples or samples with multiple peaks. Here, dynamic nuclear polarization is used to generate non-equilibrium nuclear spin states. Hyperpolarized samples can increase the nuclear-spin optical rotation signal 100-100,000 times, depending on the nuclei and experimental conditions and enable application of the method for the characterization of various chemical compounds. This new spectroscopic technique is being developed in three steps. First, nuclear-spin optical rotation of samples hyperpolarized by dynamic nuclear polarization is demonstrated. Second, the enhancement effect is characterized for various previously inaccessible nuclei and molecules, and results are compared with theory. Third, the technique is applied to the characterization of electronic structure in dye molecules. In the long term, the realization of this new spectroscopy offers a powerful analytical method for fundamental studies of light-matter interaction in liquids. The electronic structure of a molecule, both in ground and excited states, determines its basic molecular properties and reactivity. Measurements of electronic structure are necessary to understand the behavior of molecules in chemical reactions and other interactions. In this project, a new type of spectroscopy is being developed that is uniquely suited to probe spatially localized excited-state configurations of electrons. This spectroscopy is based on the measurement of an optical signal that is correlated to specific atoms in the molecule via the recently discovered nuclear-spin optical rotation effect. The project includes educational activities through a partnership between the New Mexico Consortium and Texas A&M University. Early-career scientists, including graduate an undergraduate students are being mentored, and the results from this research are incorporated into lecture classes.