Spectroscopic Investigations of Reactive Chemical Intermediates

在这项由化学系实验物理化学计划支持的项目中，俄亥俄州立大学的特里·米勒将使用腔振荡谱(CRDS)和其他技术来研究和表征活性化学中间体。自由基中间体将使用分子束喷注冷却，并将在可见光和红外光谱区域探测电子跃迁。计算将被用来帮助分析光谱，然后这将成为比较计算方法的标准。要检查的特定物种包括弱结合簇，如Ne2OH和Ne2SH，金属单甲基自由基和较大的烷基衍生物，高度不饱和碳链分子，芳基卡宾，苯基和苯氧基，烷基过氧基和卤素二氧化物。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。这些中间体在各种化学反应中发挥着关键作用，这些化学反应对于理解臭氧消耗、低大气空气污染、燃烧和天体化学等各种现象非常重要。

In this project supported by the Experimental Physical Chemistry Program of the Chemistry Division, Terry Miller of Ohio State University will use cavity ringdown spectroscopy (CRDS) and other techniques to investigate and characterize reactive chemical intermediates. Radical intermediates will be cooled using molecular-beam jets, and electronic transitions will be probed in the visible and infrared spectral regions. Calculations will be used to help analyze spectra, which then become a standard against which computational methods can be compared. Specific species to be examined include weakly bound clusters such as Ne2OH and Ne2SH, metal monomethyl radicals and larger alkyl derivatives, highly unsaturated carbon chain molecules, aryl carbenes, phenyl, and phenoxy radicals, alkyl peroxy radicals, and halogen dioxides.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. Such intermediates play critical roles in a variety of chemical reactions that are important in understanding such diverse phenomena as ozone depletion, lower-atmospheric air pollution, combustion, and astrochemistry.