Fundamental investigations on the influence of high effective ion temperatures on the kinetics of ion-molecule reactions in the gas phase using high kinetic energy ion mobility spectrometry with selective ion sources

使用选择性离子源高动能离子迁移谱分析高有效离子温度对气相离子-分子反应动力学影响的基础研究

• 批准号: 390583968
• 负责人: Professor Dr. Thorsten Benter
• 金额: --
• 依托单位: Institut für Grundlagen der Elektrotechnik und Messtechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/390583968?language=en
• 关键词: Fundamental; investigations; influence; effective; ion

The objectives of this continuation project are a) a detailed description of the kinetics of ion-molecule reactions in the gas phase as a function of the effective ion temperature on the basis of experimental investigations and b) the development of the required instrumentation in the form of a high kinetic energy ion mobility spectrometer (HiKE-IMS) with selective ion sources. While extensive data are available for room temperature to describe the kinetics of various gas phase reactions, only very few data are available for higher temperatures. Especially, experimental investigations on the kinetics of cluster association and dissociation reactions are hardly available. It is generally known that an increase in ion temperature influences the internal energy states and interaction energies between ions and neutral gas molecules and thus dissociation and fragmentation processes and the conversion rates of gas phase reactions. Within the scope of this continuation, these effects occurring at elevated ion temperatures will be fundamentally investigated. Kinetic and dynamic simulations of the processes, together with the experimental data, will finally provide new insights into the temperature-dependent kinetics of gas phase reactions, which are not only of academic interest, but also allow an application-specific optimization of the HiKE-IMS for sensitive and selective detection of certain target compounds. However, such experimental investigations require that no other reactive ions apart from the target reaction system are present in the HiKE-IMS, since parallel reactions make a clear interpretation of the measurement results difficult or impossible. The HiKE-IMS from the previous project does not yet fulfil this requirement, which is mainly due to the corona discharge source used. Within the scope of the continuation, a hollow cathode ion source compatible with the HiKE-IMS will be realized instead in order to generate defined ion populations. In addition, a laser ionization source is planned for ionizing molecules via resonant multiphoton excitation. In particular, medium polar to non-polar aromatic substances can be ionized very selectively, and tunable lasers can be used to investigate other substance classes. In addition, ions can be generated in a spatially and temporally very defined range in order to vary the residence time of the ions in the reaction region by varying the ionization site independently of other parameters. This time variation enables the calculation of reaction rates and reaction rate constants. For this purpose, a HiKE-IMS will be realized with locally variable coupling of the laser beam into the reaction region.

该延续项目的目标是 a) 在实验研究的基础上详细描述气相中离子-分子反应的动力学作为有效离子温度的函数，以及 b) 开发所需的仪器具有选择性离子源的高动能离子迁移谱仪 (HiKE-IMS)。虽然在室温下有大量数据可用于描述各种气相反应的动力学，但在较高温度下只有很少的数据可用。特别是，对簇缔合和解离反应动力学的实验研究几乎不可用。众所周知，离子温度的升高会影响离子与中性气体分子之间的内部能态和相互作用能，从而影响离解和碎裂过程以及气相反应的转化率。在此延续的范围内，将从根本上研究在升高的离子温度下发生的这些效应。过程的动力学和动态模拟以及实验数据最终将为气相反应的温度依赖性动力学提供新的见解，这不仅具有学术意义，而且还可以对 HiKE- 进行特定应用的优化。 IMS 用于灵敏、选择性地检测某些目标化合物。然而，此类实验研究要求 HiKE-IMS 中不存在除目标反应系统之外的其他反应离子，因为平行反应使得对测量结果的清晰解释变得困难或不可能。之前项目的HiKE-IMS尚未满足这一要求，这主要是由于使用了电晕放电源。在延续的范围内，将实现与 HiKE-IMS 兼容的空心阴极离子源，以生成定义的离子群。此外，计划使用激光电离源通过共振多光子激发来电离分子。特别是，中等极性到非极性芳香族物质可以非常选择性地电离，并且可调谐激光器可用于研究其他物质类别。此外，可以在空间和时间上非常限定的范围内生成离子，以便通过独立于其他参数改变电离位点来改变离子在反应区域中的停留时间。这种时间变化使得能够计算反应速率和反应速率常数。为此，将通过将激光束局部可变耦合到反应区域来实现 HiKE-IMS。