Dissociative Photodetachment Dynamics of Multiply Charged Anions

化学系的化学结构、动力学和机理(CSDM-A)项目获得该奖项，以支持加州大学圣地亚哥分校的Robert Continetti博士对孤立的多电荷阴离子的研究。这些具有额外电子的分子在广泛的化学中发挥着重要的作用，包括生物系统、催化剂和离子固体的构建块。然而，在孤立的状态下进行实验研究是非常困难的。这项研究计划涉及对孤立的多电荷阴离子的稳定性和化学的新测量，所获得的信息提供了新的见解，并指导对这些重要化学构件的更好的理论理解的发展。参与这个项目的学生正在学习一种独特仪器的设计、建造和化学应用。PI还利用与圣地亚哥当地行业(Cmer、Illumina、Air Products等)的联系，安排工业实验室的季度参观和工业科学家的研讨会，以促进整个系内代表不足的少数族裔和女性研究生的职业发展。在更技术性的层面上，该奖项允许对多电荷阴离子(MCAS)的能量学、光化学和解离动力学进行实验研究，特别是解离光分离。分离的MCAS在理论上和实验上都是具有挑战性的系统，但利用光电子和光解离光谱已经取得了重要的进展。然而，许多MCAS可以经历复杂的多重光分离和解离过程。这些研究使用电喷雾电离源和低温蓄电池离子陷阱相耦合，然后注入高能静电离子束陷阱，在那里进行光电子和光碎片测量。时间和位置敏感探测器被用来对观察到的光剥离、多重光剥离、光解离和解离光剥离过程进行三维、运动学上的完整测量。此外，在静电离子束陷阱中测量了亚稳态聚阴离子和光碎片阴离子的寿命。该项目的第一个重点是由二元酸形成的稳定的双阴离子，后来扩展到酞菁和生物相关的磺酸盐。与UCSD的Figueroa合成无机实验室合作，合成的用于催化的新型金属羰基和异氰化物配合物也在研究中。对于这些体系，没有关于该项目提供的配体解离过程和电子俘获能量学的先前实验信息。这些信息对于指导未来催化剂的设计和改进MCAS理论的发展至关重要。

With this award, the Chemical Structure, Dynamics, and Mechanism (CSDM-A) Program in the Division of Chemistry supports Dr. Robert Continetti at the University of California-San Diego in his studies of isolated multiply charged anions. These molecules with extra electrons play an important role in a wide range of chemistry, including biological systems, catalysts and as building blocks in ionic solids. However, they are very difficult to study experimentally in an isolated state. This research program involves novel measurements of the stability and chemistry of isolated multiply charged anions, with the information gained providing new insights and guiding the development of an improved theoretical understanding of these important chemical building blocks. Students involved in this project are learning about the design, construction and chemical application of a unique apparatus. The PI also uses contacts with local industry in San Diego (Cymer, Illumina, Air Products and others) to arrange quarterly tours of industrial labs and seminars by industrial scientists to enhance the career development of underrepresented minority and women graduate students across the Dept. of Chemistry and Biochemistry at UCSD.On a more technical level, this award enables experimental studies of the energetics, photochemistry and dissociation dynamics of multiply charged anions (MCAs) with a particular focus on dissociative photodetachment. Isolated MCAs are challenging systems for study theoretically and experimentally, but important progress has been made using photoelectron and photodissociation spectroscopies. However, many MCAs can undergo complex multiple photodetachment and dissociation processes. These studies use an electrospray ionization source coupled with a cryogenic accumulator ion trap prior to injection into a high-energy electrostatic ion beam trap where the photoelectron and photofragment measurements are made. Time- and position-sensitive detectors are used to make three-dimensional, kinematically complete measurements of the photodetachment, multiple photodetachment, photodissociation and dissociative photodetachment processes observed. In addition, the lifetimes of metastable polyanions and photofragment anions are measured in the electrostatic ion beam trap. The first focus of the project is on the stable dianions formed from dicarboxylic acids, later to be extended to phthalocyanines and biologically relevant sulfonates. In a collaboration with the synthetic inorganic laboratory of Figueroa at UCSD, novel metal carbonyl and isocyanide complexes synthesized for applications in catalysis are also under study. For these systems, there is no prior experimental information available on the ligand dissociation processes and electron-capture energetics that this project is providing. This information is essential for guiding the design of future catalysts and the development of an improved theory of MCAs.