Travel Grant to perform Photoionisation Studies on small Reactive Intermediates at the Elettra (Trieste) synchrotron facility

旅行补助金用于在 Elettra（的里雅斯特）同步加速器设施对小型反应中间体进行光电离研究

• 批准号: EP/H004378/1
• 负责人: John Dyke
• 金额: $ 3.24万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FH004378%2F1
• 关键词: Travel; Grant; perform; Photoionisation; Studies

Molecular radicals are molecules with an unpaired number of electrons in their ground electronic states. Because of this they are highly reactive. They are important in environments such as plasmas, combustion and the earth's atmosphere where because of their reactivity, they are often present in low concentrations. However, they play a major role in controlling the final chemical products and dominant chemical pathways observed in these environments. Ionization energies of molecular radicals, which will be measured in this work, lead to determination of heats of formation of ions and neutral molecule bond dissociation energies which can be used in models of environments such as plasmas, flames and the earth's atmosphere. The production of ions in the earth's atmosphere will be taken as an example:-Radiation from the sun entering the earth's atmosphere consists of a continuous (black-body) distribution as well as several discrete lines. A part of this radiation is sufficiently energetic to ionize molecular radicals in the atmosphere directly (i.e. non-resonantly). Another mechanism of ionisation involves production of a highly excited neutral state (a Rydberg state), above the first ionic limit which can then ionize. Studying these non-resonant and resonant processes in detail is important in terms of understanding the production of ions in different electronic and vibrational states in the earth's atmosphere. Molecular ions produced from molecular radicals are also important in plasmas, combustion and solution, and studying them via spectroscopic means, supported by electronic structure calculations, as proposed in this project helps to understand their structure and properties, and hence behaviour in these environments. In summary, photoionization processes of molecular radicals are of fundamental importance, and find application in a large number of scientific areas, including astrophysics, planetary science, the chemistry of the earth's atmosphere, radiation chemistry, physics and biology. Workers in these fields require ionisation energies and information on electronic excited neutral states and low-lying ionic states, as well as measures of intensities for photoabsorption and photoionization ( relative and absolute cross-sections) over a wide spectral range. This information is particularly useful in computer simulations and modelling of these environments.

分子自由基是在其基态电子态中具有不成对电子数的分子。正因为如此，它们具有高度的反应性。它们在等离子体、燃烧和地球大气等环境中很重要，因为它们的反应性，它们通常以低浓度存在。然而，它们在控制这些环境中观察到的最终化学产品和主要化学途径方面发挥着重要作用。分子自由基的电离能（将在这项工作中测量）可以确定离子的形成热和中性分子键解离能，这些能量可用于等离子体、火焰和地球大气等环境模型中。地球大气层中离子的产生将被视为一个例子：-从太阳进入地球大气层的辐射包括一个连续的（黑体）分布以及几个离散的线。这种辐射的一部分能量足以直接（即非共振地）摧毁大气中的分子自由基。电离的另一种机制涉及产生一个高度激发的中性态（里德堡态），高于第一个离子极限，然后可以电离。详细研究这些非共振和共振过程对于理解地球大气中不同电子和振动态离子的产生非常重要。从分子自由基产生的分子离子在等离子体、燃烧和溶液中也很重要，通过光谱手段研究它们，并得到电子结构计算的支持，如本项目所提出的，有助于了解它们的结构和性质，从而了解它们在这些环境中的行为。总之，分子自由基的光致电离过程具有根本的重要性，并且在许多科学领域中找到应用，包括天体物理学、行星科学、地球大气化学、辐射化学、物理学和生物学。这些领域的工作者需要电离能量和电子激发中性态和低离子态的信息，以及在宽光谱范围内光吸收和光电离（相对和绝对截面）强度的测量。这些信息在这些环境的计算机模拟和建模中特别有用。