Small Molecule Photodissociation in Solid Parahydrogen

固体仲氢中的小分子光解离

• 批准号: 0316268
• 负责人: David Anderson
• 金额: $ 27.77万
• 依托单位: University of Wyoming
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0316268&HistoricalAwards=false
• 关键词: Small; Molecule; Photodissociation; Solid; Parahydrogen

David Anderson of the University of Wyoming is supported by the Experimental Physical Chemistry Program for research to verify experimentally to what extent chemistry can be halted in cryogenic crystals of molecular hydrogen. Chemical impurities added to hydrogen crystals at low concentrations will be photochemically transformed in situ into reactive species such as radicals. Once the reactive species are shown to be trapped in solid hydrogen by infrared spectroscopy, laser excitation will be used to initiate chemical reactions under highly controlled conditions in order to explore low temperature condensed phase reaction dynamics at a molecular level of detail. Two important radical target species are the imidogen radical (NH) and the hydroxyl radical (OH), whose reactions with molecular hydrogen in the cryogenic hydrogen matrix will be studied. Other possible radicals for hydrogen matrix study include NO, methyl radical, and CN. Project outcomes are expected to provide chemical and photophysical information useful for predicting outcomes of laser initiated chemical reactions in novel low temperature condensed hydrogen from first principles. Frozen molecular hydrogen is an unusual condensed material, since at the low temperatures at which it solidifies, the hydrogen crystal properties are dominated by quantum mechanical behavior. Anderson's studies of reactions in solid hydrogen will test the fundamental concepts involved in low temperature condensed phase chemistry, provide insights into chemistry (or lack of it) occurring in and on the surface of planets such as Jupiter, and potentially allow for new ways of controlling chemical reaction pathways.

怀俄明大学的大卫·安德森得到了实验物理化学计划的支持，该计划的研究目的是通过实验验证分子氢的低温晶体中的化学可以停止到什么程度。添加到低浓度氢晶体中的化学杂质将被原位光化学转化为活性物种，如自由基。一旦红外光谱显示反应物种被捕获在固体氢中，激光激发将被用来在高度可控的条件下引发化学反应，以便在分子水平上探索低温凝聚相反应动力学。两个重要的自由基靶物种是亚胺基自由基(NH)和羟基自由基(OH)，它们与低温氢基质中的分子氢的反应将被研究。用于氢基质研究的其他可能的自由基包括NO、甲基自由基和CN。预计项目成果将提供化学和光物理信息，有助于从第一性原理预测激光引发的新型低温凝聚氢化学反应的结果。冷冻分子氢是一种不寻常的凝聚材料，因为在它凝固的低温下，氢的晶体性质由量子力学行为决定。安德森对固态氢中反应的研究将测试低温凝聚相化学中涉及的基本概念，为深入了解木星等行星表面发生(或缺乏化学)的化学物质提供洞察，并可能为控制化学反应途径提供新的方法。