Reaction Dynamics of Polyatomic Molecules: Low Temperature Reactions and Coherent Photodissociation

多原子分子的反应动力学：低温反应和相干光解离

基本信息

批准号：
1955239
负责人：
Arthur Suits
金额：
$ 51.7万
依托单位：
University of Missouri-Columbia
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2023-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1955239&HistoricalAwards=false
关键词：
Reaction Dynamics Polyatomic Molecules Low

项目摘要

In this project funded by the Chemical Structure, Dynamics, and Mechanism-A (CSDM-A) program of the Chemistry Division, Professor Arthur Suits and his research team at the University of Missouri, Columbia are developing new tools for studying how chemical reactions occur, in other words, how the atoms within the molecules move, how bonds are broken and new ones formed. The Suits laboratory is developing reaction chambers where the starting materials are injected as uniform supersonic flows of gas. After a pulse of laser light is applied, the changes in molecular structure caused by the laser are observed at different downstream distances. Since the flow rate is known precisely, the downstream distances correspond to time since the laser pulse, and the rates at which the molecules change structure can be calculated. The use of supersonic flows allows very fast chemical reactions to be studied. The downstream events are captured using other laser or microwave spectroscopy techniques. Microwave light causes some molecules to rotate in very specific ways, which in turn reveals information about their structure. The reactions being studied include oxygen atoms reacting with hydrocarbons with double carbon-carbon bonds (C=C) and triple bonds (C≡C), and the light-induced dissociation of ethylene sulfide (C2H4S) and nitrogen dioxide (NO2). These studies are providing new insights into how chemical reactions occur in general. The specific reactions being studied are also important for more accurate modeling of chemical reactions in the atmosphere and in astronomical environments. This project is providing training for a graduate student and a post-doctoral fellow. Data analysis software developed during the research is made available to other research groups worldwide.The research takes advantage of two unique new instruments to probe the reaction dynamics, spectroscopy, and low temperature kinetics of polyatomic molecules. The first of these instruments combines the revolutionary Chirped-pulse Fourier-transform microwave (CPTMW) technique with intense low-temperature pulsed uniform supersonic flows for kinetics and dynamics studies. The research also involves an instrument that combines the same uniform supersonic flows with high-resolution ultra-sensitive continuous-wave cavity ring-down spectroscopy (CRDS), providing capabilities complementary to those of the microwave-based system. The latter instrument has recently demonstrated Simultaneous Kinetics and Ringdown (SKaR) in a supersonic expansion for the first time. In addition to the studies in low temperature flows, the Suits team is also investigating how coherent orbital polarization reveals effects of the so-called geometric phae, wherein the system wavefunction must undergo a sign change following a transit around a conical intersection (CI). The current studies extend investigations of the geometric phase to NO2 and ethylene sulfide, promising novel probes and insights into nonadiabatic dynamics. In terms of scientific Broader Impacts, this project extends capabilities into the mid-IR spectrum, which in turn permits the application of the SKaR kinetics method to many systems of astrochemical and astronomical interest.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在这个由化学部化学结构、动力学和机理-A (CSDM-A) 项目资助的项目中，哥伦比亚密苏里大学 Arthur Suits 教授和他的研究团队正在开发新工具来研究化学反应如何发生换句话说，分子内的原子如何移动，化学键如何断裂以及新的化学键如何形成，Suits 实验室正在开发反应室，在施加激光脉冲后，起始材料以均匀的超音速气体流的形式注入。，变化由于精确已知流速，因此可以在不同的下游距离处观察到由激光引起的分子结构变化，因此下游距离对应于激光脉冲以来的时间，并且可以计算分子结构变化的速率。使用其他激光或微波光谱技术可以捕获非常快速的化学反应，微波光会导致一些分子以非常特定的方式旋转，从而揭示有关其结构的信息，其中包括氧气。与碳氢化合物反应的原子具有双碳-碳键（C = C）和三键（C = C），以及光诱导的硫化乙烯（C2H4S）和二氧化氮（NO2）的解离这些研究为化学反应的一般发生方式提供了新的见解。正在研究的特定反应对于更准确地模拟大气和天文环境中的化学反应也很重要，该项目正在为研究生和博士后研究员提供研究期间开发的数据分析软件。给其他人该研究利用两台独特的新仪器来探测多原子分子的反应动力学、光谱学和低温动力学。其中第一台仪器将革命性的啁啾脉冲傅立叶变换微波 (CPTMW) 技术与强磁场结合起来。用于动力学和动力学研究的低温脉冲均匀超音速流该研究还涉及一种将相同的均匀超音速流与高分辨率超灵敏连续波腔衰荡光谱相结合的仪器。（CRDS），该仪器最近首次在超音速膨胀中展示了后者的同步动力学和振铃（SKaR）功能，除了低温流动的研究之外。研究小组还在研究相干轨道偏振如何揭示所谓的几何相位的影响，尽管系统波函数在围绕圆锥形交叉点 (CI) 传输后必须经历符号变化。当前的研究将几何相位的研究扩展到 NO2。在更广泛的科学影响方面，该项目将能力扩展到中红外光谱，这反过来又允许将 SKaR 动力学方法应用于许多天体化学和天文学感兴趣的系统。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Multichannel Radical–Radical Reaction Dynamics of NO + Propargyl Probed by Broadband Rotational Spectroscopy

宽带旋转光谱探测 NO 炔丙基的多通道自由基-自由基反应动力学

DOI：
10.1021/acs.jpca.2c01629
发表时间：
2022-08
期刊：
The Journal of Physical Chemistry A
影响因子：
0
作者：
Dias, Nureshan;Gurusinghe, Ranil M.;Suits, Arthur G.
通讯作者：
Suits, Arthur G.

Imaging rotational energy transfer: comparative stereodynamics in CO + N 2 and CO + CO inelastic scattering

旋转能量转移成像：CO N 2 和 CO CO 非弹性散射的立体动力学比较

DOI：
10.1039/d3cp02229c
发表时间：
2023-07
期刊：
Physical Chemistry Chemical Physics
影响因子：
3.3
作者：
Sun, Zhong;Scheidsbach, Roy J.;van Hemert, Marc C.;van der Avoird, Ad;Suits, Arthur G.;Parker, David H.
通讯作者：
Parker, David H.

Coherent atomic orbital polarization probes the geometric phase in photodissociation of polyatomic molecules

相干原子轨道偏振探测多原子分子光解离的几何相位