Organic Dynamics in Crystalline Solids: Chemistry Near Zero Kelvin

通过此次续展奖项，有机和高分子化学项目继续支持Miguel A.Garcia-Garibay博士在加州大学洛杉矶分校化学和生物化学系的工作。这项研究旨在了解高度受限环境中的化学动力学--温度接近绝对零度的结晶有机固体。反应是由激光闪光光解引发的，并通过各种方法进行研究，包括X射线衍射法、差示扫描量热法、固态~(13)C核磁共振、红外和拉曼光谱。量子力学隧穿将通过氚同位素效应、速率常数的反常Arrhenius图以及理论和计算化学来研究。拟议的工作涉及高活性有机中间体的反应性变化，这些中间体是通过光化学产生的，当这些中间体不是在有相当大运动自由的液体溶液中形成时，而是在低温下高度受限的晶体固体中形成的。在这种情况下，可能会形成不寻常的产品，其速率远远高于基于室温附近的速率预期的速率。这类研究可以深入了解所涉及的反应的详细动力学。这项工作为学生在有机合成、光谱学、动力学和计算化学方面提供了极好的培训。PI积极招募未被充分代表的少数民族学生，特别是西班牙裔学生，在他的实验室进行研究。

With this renewal award the Organic and Macromolecular Chemistry Program continues support for the work of Dr. Miguel A. Garcia-Garibay in the Department of Chemistry and Biochemistry at the University of California, Los Angeles. The research aims at understanding chemical dynamics in highly constrained environments - crystalline organic solids at temperatures approaching absolute zero. Reactions are initiated by laser flash photolysis and studied by a variety of methods including x-ray diffraction, differential scanning calorimetry, solid state 13C NMR, and infrared and Raman spectroscopy. Quantum mechanical tunneling will be studied by means of deuterium isotope effects, anomalous Arrhenius plots of rate constants, and by theoretical and computational chemistry.The proposed work involves the changes in reactivity of highly reactive organic intermediates, generated photochemically, when these intermediates are formed not in liquid solution where there is considerable freedom of motion, but in highly constrained crystalline solids at low temperatures. Unusual products can form under these circumstances at rates that are much higher than would be expected based on rates near room temperature. Studies of this type can give insight into the detailed dynamics of the reactions involved. The work provides excellent training for students in organic synthesis, spectroscopy, kinetics, and computational chemistry. The PI actively recruits underrepresented minority students, especially Hispanics, to do research in his laboratory.