Spectroscopic studies of molecular ions and radicals in the low frequency regime

低频范围内分子离子和自由基的光谱研究

• 批准号: 326993-2010
• 负责人: VanWijngaarden, Jennifer
• 金额: $ 2.91万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571895
• 关键词: Spectroscopic; studies; molecular; ions; radicals

Despite their short lifetimes, molecular ions and radicals are of great importance in numerous chemical processes such as combustion, semiconductor fabrication and polymerization. Although they drive the chemistry in these environments, their properties are not well characterized. A more complete understanding of the nature of isolated reactive intermediates is a first step for exploring their interactions with other molecules and their roles in chemical reactions. Thus, the accurate characterization of molecular ions and radicals has implications to our understanding of processes of economic importance such as combustion engines, to processes with global impact such as pollution control and to even larger scale processes such as those responsible for the evolution of the Universe. The main objective of this research program is to use high resolution microwave and infrared spectroscopy to derive accurate and detailed molecular information for ions and radicals. Fundamental properties such as structure are intrinsically linked to the molecule's potential energy surface and thus, the observed spectra are unique fingerprints by which to identify reactive species and probe their roles in various environments. Target molecules include short-lived species found in hydrocarbon flames (protonated alcohols), the Earth's atmosphere (peroxy radicals) and astronomical sources (carbon-based ions/radicals). The techniques used to characterize the ground state molecular parameters of reactive species are i) Fourier transform microwave (FTMW) and ii) chirped pulse-FTMW spectroscopy using custom-built instruments at the University of Manitoba. The low frequency bending and torsional motions of these moieties will be probed using iii) FT infrared spectroscopy at the far infrared beamline of the Canadian Light Source.

尽管分子离子和自由基的寿命很短，但它们在燃烧、半导体制造和聚合等众多化学过程中都具有重要的作用。尽管它们推动了这些环境中的化学作用，但它们的性质还没有得到很好的表征。更全面地了解孤立的活性中间体的性质是探索它们与其他分子的相互作用以及它们在化学反应中的作用的第一步。因此，分子离子和自由基的准确表征对我们理解具有重要经济意义的过程，如内燃机，对全球有影响的过程，如污染控制，以及更大规模的过程，如那些负责宇宙演化的过程都有影响。 这项研究计划的主要目标是使用高分辨率的微波和红外光谱来获得准确和详细的离子和自由基的分子信息。结构等基本性质与分子的势能面有着内在的联系，因此，观察到的光谱是唯一的指纹，可以用来识别活性物种并探索它们在各种环境中的作用。目标分子包括在碳氢化合物火焰(质子化醇)、地球大气(过氧基)和天文来源(碳基离子/自由基)中发现的短期物种。 用于表征活性物种基态分子参数的技术有i)傅里叶变换微波(FTMW)和ii)使用马尼托巴大学定制仪器的啁啾脉冲FTMW光谱。这些部分的低频弯曲和扭转运动将在加拿大光源的远红外光束线上使用III)FT红外光谱来探测。