CAREER: Laser Spectroscopic Investigation of Vibronic Interactions in Free Radicals and Molecular Complexes

有了这个CAREER奖，化学系的化学结构，动力学和机制（CSDM-A）计划资助路易斯维尔大学的Jinjun Liu教授进行实验研究，旨在了解振动和电子运动如何在小反应分子和离子二聚体中耦合。这种电子和振动自由度的耦合在光化学反应中是普遍存在的，这是大气化学和其他场所中的一类重要反应。从事该项目的博士后，研究生和本科生将接受激光科学，光谱学和实验仪器设计方面的培训，同时研究具有重大现实影响的引人注目的化学问题。此外，该项目还包括物理化学课程的改革和学生参与研究等多个教育项目。刘进军教授及其研究小组将利用一套光谱技术研究对大气化学、燃烧化学等领域有重要意义的化学物种的电子振动相互作用。待研究的物种包括将在放电中产生的烷氧基自由基和将用加热喷嘴产生的离子液体的离子对。用于询问这些分子的方法包括：（1）激光诱导荧光（LIF）;（2）分散荧光（DF）;（3）和腔衰荡光谱（CRDS）。更具体地说，烷氧基自由基中间体将产生脉冲放电或激光光解，而离子液体的离子对，一个光谱下探索家庭的分子复合物，将在气相中使用加热的喷嘴进行研究。LIF和紫外CRDS实验将用于探索高电子态的振动能级，而DF和中红外CRDS技术将用于研究最低电子态的振动结构。分离离子液体的光谱研究旨在了解离子对之间的库仑相互作用和氢键，确定分子复合物的构象，并将其微观结构与理化性质联系起来。 特别是，可以预期，关于Jahn-Teller和伪Jahn-Teller相互作用的工作将引起理论家的极大兴趣。

With this CAREER award, the Chemical Structure, Dynamics and Mechanisms (CSDM-A) Program of the Division of Chemistry is funding Professor Jinjun Liu of the University of Louisville to conduct experimental studies aimed at understanding how the vibration and electron motion are coupled in small reactive molecules and in ionic dimers. This coupling of electronic and vibrational degrees of freedom is ubiquitous in photochemical reactions, which are an important class of reactions in atmospheric chemistry and in other venues. Post-doctoral, graduate and undergraduate students working on this project will receive training in laser science, spectroscopy, and the design of experimental apparatus, while working on compelling chemical problems with significant real-world impact. Part of this CAREER program is also focused on a number of education projects, including the revamping of the physical chemistry curriculum and the involvement of underrepresented students in his research program.Professor Jinjun Liu and his research group will use a suite of spectroscopic techniques to study the vibronic interactions in chemical species of significance to atmospheric chemistry, combustion chemistry, and other areas. Species to be studied include alkoxy radicals which will be created in an electric discharge and ion pairs of ionic liquids will be created with a heated nozzle. The methods used to interrogate these molecules include: (1) laser induced fluorescence (LIF); (2) dispersed fluorescence (DF); (3) and cavity ringdown spectroscopy (CRDS). More specifically, the alkoxy radical intermediates will be generated by either pulsed electric discharge or laser photolysis, while ion pairs of ionic liquids, a spectroscopically underexplored family of molecular complexes, will be studied in the gas phase using a heated nozzle. LIF and Ultraviolet-CRDS experiments will be conducted to explore the vibrational energy levels of high-lying electronic states, whereas DF- and mid-Infrared-CRDS techniques will be used to investigate the vibronic structure of the lowest electronic states. Spectroscopic study of isolated ionic liquids is aimed at understanding the Coulombic interaction and hydrogen bonding between ion pairs, determining the conformations of the molecular complexes, and connecting their microscopic structure to physiochemical properties. In particular, it is anticipated that the work on Jahn-Teller and pseudo Jahn-Teller interactions will be of considerable interest to theorists.