Spectroscopic Detection and Characterization of Chemical Intermediates

在化学系物理化学计划的这个项目中，俄亥俄州立大学的特里·A·米勒教授将对涉及到它们的化学反应中间体和团簇进行基础研究。检测和表征物种的主要方法是高分辨率光谱分析。这些物种是在超音速喷射膨胀的寒冷、无反应的环境中产生的，在那里它们可以用中分辨率和极高分辨率的激光诱导荧光(LIF)光谱进行检测。使用相同的喷射技术，将表征一些反应性、中性自由基的化学非常重要的离子的零动能(ZEKE)光谱。要作为中性和/或阳离子研究的特定化学中间体包括烷氧基及其氟代和硫代衍生物、卡宾、胺基和相关自由基，以及取代的甲基自由基(碳离子)。同时还将开展基础光谱学理论、应用光谱分析和化学中间体从头计算方面的理论发展。在大气、燃烧和有机合成过程中发生的复杂化学反应通常涉及决定整个过程结果的瞬时化学中间体，如自由基和分子离子。中间体的光谱鉴定对于实际研究和监测此类反应至关重要。中间体的光谱表征为基本理解化学反应的性质提供了基础。这项研究涉及对这些中间体和涉及它们的物种进行光谱检测和表征的多方面方法。

In this project in the Physical Chemistry Program of the Chemistry Division, Prof. Terry A. Miller of the Ohio State University will conduct fundamental investigations of chemical reaction intermediates and clusters involving them. The primary method for detection and characterization of the species is high resolution spectroscopy. The species are produced in the cold, unreactive environment of a supersonic jet expansion where they can be interrogated by bot moderate and very high resolution laser induced fluorescence (LIF) spectroscopy. Using the same jet techniques, the zero kinetic energy (ZEKE) spectroscopy of the chemically very important ions of a number of reactive, neutral free radicals will be characterized. Specific chemical intermediates to be studied as neutrals and/or cations include alkoxy radicals and their fluoro- and thio-derivatives, carbenes, amiodogen and related radicals, and substituted methyl radicals (carbonium ions). Concurrent theoretical developments in fundamental spectroscopic theory, applied spectroscopic analysis, and ab initio calculations on the chemical intermediates will be undertaken. Complex chemical reactions that occur in atmospheric, combustion, and organic synthesis processes typically involve transient chemical intermediates, such as free radicals and molecular ions, that determine the overall result of the process. Spectroscopic identification of the intermediates is critical for the practical investigation and monitoring of such reactions. Spectroscopic characterization of the intermediates provides a foundation for the basic understanding of the nature of chemical reactivity. This research involves a multifaceted approach to the spectroscopic detection and characterization of these intermediates and species involving them.