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.

在该项目中，化学部门的化学结构，动力学和机制（CSDM-A）计划，亚瑟·西特（Arthur Suits）教授及其在密苏里大学的研究团队正在开发新的工具，以研究化学反应的新工具，换句话说，换句话说，分子内部的原子如何移动，键合成键，并形成了新的。西装实验室正在开发反应室，将起始材料注射为均匀的超音速气体。应用激光脉冲后，在不同的下游距离下观察到由激光引起的分子结构的变化。由于流速是精确知道的，因此下游距离对应于激光脉冲以来的时间，以及可以计算分子变化结构的速率。超音速流的使用允许研究非常快速的化学反应。下游事件是使用其他激光或微波光谱技术捕获的。微波光导致某些分子以非常特定的方式旋转，从而揭示了有关其结构的信息。正在研究的反应包括与双碳碳键（C = C）和三键（C区）反应的氧原子，以及乙烯硫化物（C2H4S）和硝基二氧化物（NO2）的光诱导的光诱导的解离。这些研究提供了有关化学反应通常如何发生的新见解。特定反应对于在大气和天文环境中更准确地建模化学反应也很重要。该项目正在为研究生和博士后研究员提供培训。在研究期间开发的数据分析软件可供全球其他研究小组提供。该研究利用两种独特的新仪器来探测多原子分子的反应动力学，光谱和低温动力学。这些仪器中的第一种结合了革命性的pulsed脉冲傅立叶转换微波炉（CPTMW）技术与强烈的低温脉冲均匀均匀的超音速流，用于动力学和动力学研究。这项研究还涉及一种仪器，将相同的超音速流与高分辨率的超敏感连续波腔响起光谱（CRDS）结合在一起，为基于微波炉的系统提供了功能。后来的仪器最近首次表现出同时的动力学和铃声（Skar）（Skar）。除了在低温流动中进行研究外，套装团队还研究了相干轨道极化如何揭示所谓的几何PHAE的影响，其中系统波函数必须在临床交叉点（CI）周围的过境后进行符号变化。当前的研究将几何阶段的研究扩展到NO2和硫化乙烯，答应了新的问题和对非绝热动态的见解。就科学广泛的影响而言，该项目将能力扩展到中期频谱，这反过来允许将Skar动力学方法应用于许多天文学和天文学兴趣系统中。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识优点和广泛影响的评估来评估的值得支持的。

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）

Uniform supersonic flow sampling for detection by chirped-pulse rotational spectroscopy

用于通过啁啾脉冲旋转光谱检测的均匀超音速流采样

DOI：
10.1063/5.0073527
发表时间：
2022
期刊：
The Journal of Chemical Physics
影响因子：
0
作者：
Gurusinghe, Ranil M.;Dias, Nureshan;Krueger, Ritter;Suits, Arthur G.
通讯作者：
Suits, Arthur G.

Radical–Radical Reaction Dynamics Probed Using Millimeterwave Spectroscopy: Propargyl + NH 2 /ND 2

使用毫米波光谱探测自由基 - 自由基反应动力学：丙炔 NH 2 /ND 2

DOI：
10.1021/acs.jpclett.1c03813
发表时间：
2022
期刊：
The Journal of Physical Chemistry Letters
影响因子：
0
作者：
Gurusinghe, Ranil M.;Dias, Nureshan;Mebel, Alexander M.;Suits, Arthur G.
通讯作者：
Suits, Arthur G.

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

DOI：
10.1002/ntls.20220013
发表时间：
2022
期刊：
Natural Sciences
影响因子：
0
作者：
Weeraratna, Chaya;Suits, Arthur G.;Vasyutinskii, Oleg S.
通讯作者：
Vasyutinskii, Oleg S.

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
期刊：
Physical Chemistry Chemical Physics
影响因子：
3.3
作者：
Sun, Zhong-Fa;Scheidsbach, Roy J.;van Hemert, Marc C.;van der Avoird, Ad;Suits, Arthur G.;Parker, David H.
通讯作者：
Parker, David H.

Molecular square dancing in CO-CO collisions