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.

分子自由基是其地面电子状态中数量不足的电子的分子。因此，它们具有高度反应性。它们在等离子体，燃烧和地球大气等环境中很重要，由于它们的反应性，它们通常以低浓度存在。但是，它们在控制最终化学产品和在这些环境中观察到的主要化学途径中起着重要作用。将在这项工作中测量的分子自由基的电离能导致确定离子形成和中性分子键离解的热量，这些热量可用于等离子体，火焰和地球大气的模型。地球大气中离子的产生将以一个例子为例： - 从太阳进入地球大气层的传播由连续的（黑色）分布以及几种离散线组成。该辐射的一部分足以使大气中的分子自由基直接电离（即非刺激性）。电离的另一种机制涉及产生高度激发的中性态（rydberg状态），高于第一个离子极限，然后可以电离。在了解地球大气中不同电子和振动状态下离子的产生方面，研究这些非谐振和共振过程很重要。由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，并通过光谱式手段对其进行研究，并得到电子结构计算的支持，如本项目中所建议的，有助于理解其结构和性质，从而在这些环境中行为。总而言之，分子自由基的光电离过程至关重要，并且在包括天体物理学，行星科学，地球大气的化学，辐射化学，物理学和生物学在内的许多科学领域找到了应用。这些领域中的工人需要电离能量和有关电子激发中性状态和低洼离子状态的信息，以及在广泛的光谱范围内的光吸收和光电离（相对和绝对横截面）的强度。这些信息在计算机模拟和对这些环境的建模中特别有用。