State-Resolved Spectroscopy and Dynamics of Chemical Transients

状态分辨光谱和化学瞬态动力学

• 批准号: 2053117
• 负责人: David Nesbitt
• 金额: $ 67.37万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2053117&HistoricalAwards=false
• 关键词: State; Resolved; Spectroscopy; Dynamics; Chemical

In this project funded by the Chemical Structure Dynamics and Mechanisms A (CSDM-A) program of the Chemistry Division, Professor David Nesbitt of the University of Colorado uses sophisticated laser spectroscopy and molecular beam techniques to probe reactive chemical intermediate species at the gas-liquid interface. The curious paradox of chemistry is that the chemical intermediates of greatest relevance are necessarily present in vanishingly low concentrations and therefore require higher and higher sensitivity detection methods to observe. Nowhere are these sensitivity needs more pronounced than at the gas-liquid interface, whereby an ultrathin layer (10-7 cm) serves as the “doorway” between molecules in the gas phase and deep inside the bulk liquid. The proposed research is directed towards systematic exploration of such interfaces, exploiting high resolution laser spectroscopy and molecular beam tools to “bounce” molecules from liquids and probing the chemical composition, vibrational, rotational, speeds, and directions in which the product scatters from the surface. Prof. Nesbitt is continuing his 31st-33rd years as director of the CU Wizards Science Outreach program, which entails organizing 10 demo-filled science presentations each academic year (from September to June) for children in lower and middle school, in areas of science ranging from Black Holes to the Physics of Cooking to the What's Behind Climate Change? In particular, the proposed studies are exploiting supersonic expansions of simple molecules (e.g., DCl, HCl, CO, CO2, OCS, NO) moving at up to 2000 m/s (2-10x faster than the speed of sound) colliding with simple liquids (e.g., water, salty water, glycerin, hydrocarbon oils, molten salts, and even molten gold at 1100 C!). Nesbitt’s students are utilizing high resolution laser spectroscopy to explore how cold molecular projectiles “warm up to” and even significantly exceed the temperature of the bulk liquid. These results turn out to depend sensitively on and therefore quantitatively probe the nature of this thin interfacial layer (e.g., is it “rough” vs “smooth”, “soft” vs “hard”, “acidic” or “basic”, or “water-hating” (hydrophobic) vs. “water-loving” (hydrophilic), etc.), thereby providing detailed insights into the collision dynamics and chemistry of molecules at interfaces. This is relevant to how, for example, molecules such as O2 and CO2 cross through the lungs, dissolve into the blood stream, and eventually enter/leave the cells in any living organism. The gas-liquid interface is arguably the least well understood phase of matter and yet represents the sole “portal” through which gas molecules can dissolve into (or be expelled out of) a liquid. The gas-liquid interface thus represents a new scientific frontier about which remarkably little is known, but which nevertheless has impacts in areas as disparate as pulmonary medicine, ocean surface layer chemistry, atmospheric aerosol chemistry, ozone hole formation, and global climate change.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.

在这个由化学系化学结构动力学和机理A(CSDM-A)计划资助的项目中，科罗拉多大学的David Nesbitt教授使用先进的激光光谱和分子束技术来探测气液界面上的活性化学中间体。化学中奇怪的悖论是，最相关的化学中间体必然以极低的浓度存在，因此需要越来越高的灵敏度检测方法来观察。在气液界面上，这些敏感性需求最为明显。在气液界面上，一层超薄层(10-7厘米)充当气相分子和大块液体内部分子之间的“通道”。拟议的研究旨在系统地探索这种界面，利用高分辨率激光光谱学和分子束工具从液体中“反弹”分子，并探测产品从表面散射的化学成分、振动、旋转、速度和方向。内斯比特教授继续担任加州大学奇才科学外展项目主任的第31-33年，该项目需要在每个学年(从9月到6月)为初中和中学的孩子们组织10个充满演示的科学报告，内容从黑洞到烹饪物理再到气候变化背后的什么？特别是，拟议的研究利用了简单分子(例如DCL、HCl、CO、CO2、OCS、NO)以高达2000米/S(比音速快2-10倍)的速度与简单液体(例如水、咸水、甘油、碳氢油、熔盐，甚至在1100℃熔融的金！)碰撞的超音速膨胀。奈斯比特的学生正在利用高分辨率激光光谱学来探索冷分子抛射体如何“升温”，甚至显著超过大块液体的温度。这些结果敏感地依赖于并因此定量地探测这种薄界面层的性质(例如，它是“粗糙”与“光滑”、“软”与“硬”、“酸性”或“碱性”，或“憎水”(疏水)与“爱水”(亲水)，从而提供了对界面分子碰撞动力学和化学的详细见解。例如，这与O2和CO2等分子如何穿过肺部，溶解到血液中，并最终进入/离开任何活着的有机体的细胞有关。气液界面可以说是最不为人所知的物质相，但却是气体分子可以溶解到液体中(或从液体中排出)的唯一“入口”。因此，气液界面代表了一个新的科学前沿，人们对此知之甚少，但它对肺部医学、海洋表层化学、大气气溶胶化学、臭氧层形成和全球气候变化等领域都有影响。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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

High-resolution rovibrational spectroscopy of trans-formic acid in the v1 OH stretching fundamental: Dark state coupling and evidence for charge delocalization dynamics

v1 OH 拉伸基础中反式甲酸的高分辨率振动光谱：暗态耦合和电荷离域动力学的证据

• DOI: 10.1016/j.jms.2023.111743
• 发表时间: 2023
• 期刊: Journal of Molecular Spectroscopy
• 影响因子: 1.4
• 作者: Chan, Ya-Chu;Nesbitt, David J.
• 通讯作者: Nesbitt, David J.

Non-equilibrium dynamics at the gas–liquid interface: State-resolved studies of NO evaporation from a benzyl alcohol liquid microjet

气液界面的非平衡动力学：苯甲醇液体微射流中 NO 蒸发的状态解析研究

• DOI: 10.1063/5.0143254
• 发表时间: 2023
• 期刊: The Journal of Chemical Physics
• 作者: Ryazanov, Mikhail;Nesbitt, David J.
• 通讯作者: Nesbitt, David J.

Synergism in the Molecular Crowding of Ligand-Induced Riboswitch Folding: Kinetic/Thermodynamic Insights from Single-Molecule Spectroscopy

配体诱导的核糖开关折叠的分子拥挤中的协同作用：来自单分子光谱的动力学/热力学见解

• DOI: 10.1021/acs.jpcb.2c03507
• 发表时间: 2022
• 期刊: The Journal of Physical Chemistry B
• 作者: Sung, Hsuan-Lei;Nesbitt, David J.
• 通讯作者: Nesbitt, David J.

Breath analysis by ultra-sensitive broadband laser spectroscopy detects SARS-CoV-2 infection

通过超灵敏宽带激光光谱进行呼吸分析可检测 SARS-CoV-2 感染

• DOI: 10.1088/1752-7163/acc6e4
• 发表时间: 2023
• 期刊: Journal of Breath Research
• 影响因子: 3.8
• 作者: Liang, Qizhong;Chan, Ya-Chu;Toscano, Jutta;Bjorkman, Kristen K;Leinwand, Leslie A;Parker, Roy;Nozik, Eva S;Nesbitt, David J;Ye, Jun
• 通讯作者: Ye, Jun

High-resolution CH stretch spectroscopy of jet-cooled cyclopentyl radical: First insights into equilibrium structure, out-of-plane puckering, and IVR dynamics

喷射冷却环戊基自由基的高分辨率 CH 拉伸光谱：首次深入了解平衡结构、面外褶皱和 IVR 动力学

• DOI: 10.1063/5.0096946
• 发表时间: 2022
• 期刊: The Journal of Chemical Physics
• 作者: Kortyna, Andrew;Reber, Melanie A.;Nesbitt, David J.
• 通讯作者: Nesbitt, David J.