Matrix Spectroscopic Studies of Novel Chemical Species

在化学学部实验物理化学项目的这个项目中，弗吉尼亚大学的Lester Andrews教授将研究一些外来化学物质的基质分离光谱。在这项工作中要研究的系统包括具有pi电子系统的金属原子配合物，与碳硼烷的金属配合物，过渡金属氢化物或二氢配合物，涉及一氧化碳和分子氢作为模型费托催化剂的过渡金属配合物，铝原子与小分子的反应，和重族VA和VIA原子化学。在许多实验中，将使用脉冲激光蒸发方法来形成金属配合物，而微波放电将用于制造金属团簇。红外和电子吸收以及共振拉曼光谱是将要使用的实验工具之一。安德鲁斯教授使用基质分离光谱学技术来研究分子的结构，这些分子非常不稳定，通常在普通实验室条件下无法观察到。在这项技术中，产生感兴趣的物种，然后在极低的温度下快速捕获在冷冻稀有气体基质中。所研究的物种包括在化学反应中形成的中间体、弱结合分子或高活性形式。这种分子很难或不可能用其他实验技术来表征。

In this project in the Experimental Physical Chemistry Program of the Chemistry Division, Professor Lester Andrews of the University of Virginia will investigate the matrix isolation spectroscopy of some exotic chemical species. Systems to be examined in this work include metal atom complexes having pi-electron systems, metal complexes with carboranes, transition metal hydride or dihydrogen complexes, transition metal complexes involving carbon monoxide and molecular hydrogen as model Fischer-Tropsch catalysts, aluminum atom reactions with small molecules, and heavy Group VA and VIA atom chemistry. A pulsed-laser evaporation method will be used in many of these experiments to form the metal complexes, while microwave discharges will be used to make metal clusters. Infrared and electronic absorption and resonance Raman spectroscopy are among the experimental tools to be used. %%% Professor Andrews uses the technique of matrix isolation spectroscopy to study the structure of molecules which are so unstable that they normally are not observed under ordinary laboratory conditions. In this technique, the species of interest are generated and then quickly trapped at very low temperatures in frozen rare gas matrices. Included among species studied are the intermediates formed in chemical reactions, weakly-bound molecules, or highly reactive forms. Such molecules are difficult or impossible to characterize by other experimental techniques.