High-Accuracy Thermochemistry with Threshold and Imaging Photoelectron Photoion Coincidence Spectroscopy

通过这个奖项，由化学结构，动力学和机制-化学系的一个项目资助，来自太平洋大学的Bálint Sztáray教授将表征具有燃烧或大气相关性的分子和自由基的热化学。使用光电子光离子符合光谱，将提供燃烧和大气模型中三个最重要的参数集的显着改进：准确的实验热化学数据，反应速率和能量分布。实验将在太平洋大学的实验室仪器上进行，该仪器将获得新的离子速度图成像装置的升级，并在瑞士光源同步加速器的成像光电子光离子符合光谱终端站上进行。结合实验离子碎裂和速度分布数据与高层次的量子化学计算，将提供统计率和能量分布理论的理解，以改善燃烧和大气模型中使用的动力学建模工具的进步。能量可以说是最重要的物理量，影响几乎每一个方面的物理，化学和生物过程。分子结构的化学变化几乎总是伴随着能量的变化，这决定了哪些化学反应是可能的。由于燃烧过程的主要目的是从化学系统中提取能量，因此表征燃烧中所涉及的各种分子和碎片的能量含量是建立预测模型的基础。热化学，研究能量在化学过程中的作用，在过去的十年中经历了变革性的变化，部分原因是计算方法的进步，另一部分原因是新的整体模型，其中远程相关系统中的能量变化连接在一个复杂的能量关系网络中。在过去的几年里，计算方法已经接近甚至超过了实验精度，它们需要新的和更准确的实验数据来进行测试。在这项研究中使用的实验方法将提供一些最准确的数字，对各种各样的系统，涉及燃烧或大气过程。

Through this award, funded by the Chemical Structure, Dynamics, and Mechanisms - A Program of the Division of Chemistry, Prof. Bálint Sztáray from the University of the Pacific, will characterize the thermochemistry of molecules and radicals that have combustion or atmospheric relevance. Using Photoelectron Photoion Coincidence Spectroscopy, significant improvements will be offered to three of the most important parameter sets in combustion and atmospheric models: accurate experimental thermochemical data, reaction rates, and energy distributions. The experiments will be conducted both on the lab-based instrument at the University of the Pacific, which will receive an upgrade of a new ion velocity map imaging setup, and on the Imaging Photoelectron Photoion Coincidence Spectroscopy endstation at the Swiss Light Source synchrotron. Combining experimental ion fragmentation and velocity distribution data with high-level quantum chemical calculations, advances will be offered in the understanding of statistical rate and energy distribution theories to improve the kinetics modeling tools used in combustion and atmospheric models.Energy is arguably the most important physical quantity, affecting almost every aspect of physical, chemical and biological processes. Chemical changes in the structure of molecules are almost invariably accompanied by changes in the energy, determining which chemical reactions are possible. As the primary purpose of combustion processes is to extract energy from chemical systems, characterizing the energy content of the various molecules and fragments involved in combustion is the foundation on which predictive models can be built. Thermochemistry, the study of the role of energy in chemical processes, has gone through transformative changes in the last decade, partly due to advances in computational methods and party due to new holistic models in which energy changes in remotely related systems are connected in a complex web of energy relationships. Computational methods in the past few years have approached and even exceeded experimental accuracy and they need new and more accurate experimental data to be tested against. The experimental methods used in this research will provide some of the most accurate numbers on a wide variety of systems that are involved in combustion or atmospheric processes.