Photoinitiated Dynamics of Transient Species: Hydrogen-Bonded Clusters

瞬态物质的光引发动力学：氢键团簇

• 批准号: 1664994
• 负责人: Hanna Reisler
• 金额: $ 43.75万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-15 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1664994&HistoricalAwards=false
• 关键词: Photoinitiated; Dynamics; Transient; Species; Hydrogen

In this project, supported by the Chemical Structure, Dynamics and Mechanisms - A (CSDM-A) and Macromolecular, Supramolecular and Nanochemistry (MSN) Programs of the Division of Chemistry, Professor Hanna Reisler of the University of Southern California uses lasers to initiate chemical reactions and then observe how the molecules dissociate (fall apart), dissipate the energy they absorbed from the laser light, or behave as acids under light exposure. The Reisler group is particularly interested in hydrogen-bonded complexes of molecules and nanoparticles in water containing a few molecules of hydrochloric acid (HCl) and organic molecules such as benzene or phenol. Hydrogen bonds are formed from the attraction of partially negatively-charged atoms such as oxygen on one molecule and the partially positive charge of a hydrogen atom on a neighboring molecule. Hydrogen-bonded networks influence chemical and biological function and are implicated in the identity of icy bodies in the solar system. Hydrogen bonding is not yet well understood because of difficulties in defining the experimental conditions. Professor Reisler overcomes these challenges by selecting water aggregates that contain a specific number of solute molecules, then uses laser techniques that have high detection sensitivity for the molecules and reactions of interest. The broader impacts of the project include potential societal benefits arising from better understanding the effects of hydrogen bonding on the reactivity of molecules in the atmosphere and other water-rich environments, like the human body. Students and postdoctoral researchers build advanced instrumentation, preparing them high technology careers. Professor Reisler, a leader in mentoring of women in science fields, continues her activities in encouraging students from underrepresented groups to pursue careers in science, technology, engineering and mathematics.The current research focuses on three topics: (1) energy flow pathways in the predissociation of dimers of water with aromatic molecules;(2) measurements of hydrogen-bond dissociation energies in cyclic trimers and tetramers with specific HCl and water subunits; and (3) interactions of nanoscale water samples with protons. By recording images of specific rovibrational levels of one fragment of the dissociated cluster, the rovibrational energy distributions in the cofragments are determined, demonstrating how geometry and hydrogen-bonding type influence energy disposal. This provides stringent tests of theories and proposed mechanisms. In order to study the emergence of acidity in condensed phase aggregates, nanofabricated arrays of gold nanoparticles are covered with solid water and rapid heating is achieved by visible irradiation that excites the plasmon resonance of the gold nanoparticles. A 0.5 mm diameter laser pulse excites over a million nanoparticles. The effect of a single laser pulse on solid water doped with HCl is studied using isotope exchange to probe acidity.

在这个项目中，由化学系的化学结构，动力学和机制- A（CSDM-A）和大分子，超分子和纳米化学（MSN）计划支持，南加州大学的Hanna Reisler教授使用激光引发化学反应，然后观察分子如何解离（分解），耗散它们从激光吸收的能量，或者在光暴露下表现为酸。Reisler小组对水溶液中分子和纳米颗粒的氢键复合物特别感兴趣，其中含有几个盐酸分子和有机分子，如苯或苯酚。 氢键是由一个分子上的部分带负电荷的原子（如氧）和相邻分子上的氢原子的部分正电荷的吸引力形成的。氢键网络影响化学和生物功能，并与太阳系中冰体的身份有关。由于在确定实验条件方面的困难，氢键还没有得到很好的理解。Reisler教授通过选择含有特定数量溶质分子的水聚集体克服了这些挑战，然后使用对感兴趣的分子和反应具有高检测灵敏度的激光技术。该项目的更广泛影响包括更好地理解氢键对大气和其他富水环境（如人体）中分子反应性的影响所产生的潜在社会效益。 学生和博士后研究人员建立先进的仪器，为他们的高科技职业生涯做准备。Reisler教授是一位在科学领域指导女性的领导者，她继续鼓励来自代表性不足群体的学生从事科学、技术、工程和数学方面的职业。目前的研究集中在三个主题：（1）水与芳香分子二聚体预解离的能量流动途径;（2）测量具有特定HCl和水亚基的环状三聚体和四聚体中的氢键解离能;（3）纳米级水样与质子的相互作用。 通过记录特定的振转能级的图像的一个片段的解离集群，在cofragles的振转能量分布的确定，演示几何形状和氢键类型如何影响能量处置。这为理论和提出的机制提供了严格的测试。 为了研究凝聚相聚集体中酸性的出现，用固体水覆盖金纳米颗粒的纳米制造阵列，并通过激发金纳米颗粒的等离子体共振的可见光照射实现快速加热。直径为0.5 mm的激光脉冲激发了超过一百万个纳米颗粒。 用同位素交换法研究了单脉冲激光对固体水的影响。

项目成果

Hanna Reisler: Autobiographical Notes

汉娜·赖斯勒：自传笔记

• DOI: 10.1021/acs.jpca.9b04416
• 发表时间: 2019
• 期刊: The Journal of Physical Chemistry A
• 作者: Reisler, Hanna

Vibrational predissociation of the phenol–water dimer: a view from the water

苯酚-水二聚体的振动预解离：从水中观察

• DOI: 10.1039/c8cp06581k
• 发表时间: 2019
• 期刊: Physical Chemistry Chemical Physics
• 影响因子: 3.3
• 作者: Kwasniewski, Daniel;Butler, Mitchell;Reisler, Hanna
• 通讯作者: Reisler, Hanna

Predissociation dynamics of the HCl–(H 2 O) 3 tetramer: An experimental and theoretical investigation

HCl–(H 2 O) 3 四聚体的预解离动力学：实验和理论研究

• DOI: 10.1063/1.5026585
• 发表时间: 2018
• 期刊: The Journal of Chemical Physics
• 作者: Zuraski, Kristen;Wang, Qingfeng;Kwasniewski, Daniel;Bowman, Joel M.;Reisler, Hanna
• 通讯作者: Reisler, Hanna