STM and STS Studies of the Structures and Energetics of Axial Ligand Coordination to Metal Porphyrins at the Liquid-Solid Interface

液固界面金属卟啉轴向配体配位的结构和能量的 STM 和 STS 研究

• 批准号: 1112156
• 负责人: Ursula Mazur
• 金额: $ 41.9万
• 依托单位: Washington State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1112156&HistoricalAwards=false
• 关键词: STM; STS; Studies; Structures; Energetics

The Chemical Structure, Dynamics and Mechanisms Program of the Chemistry Division supports Professor Ursula Mazur at the Washington State University for studies of axial ligand coordination to metal porphyrins (MPs) at the liquid-solid interface. Systematic studies will be performed on the reactions of MPs with an axially coordinated ligand and the electronic orbital structures and energies in these systems will be mapped using scanning tunneling microscopy (STM). These studies will measure deviations from planarity of the MP induced by ligand attachment, identify and map both the metal and the ligand orbitals in the MP complexes, compare the observed density of states for the MP systems to model electronic calculations, and measure kinetics in cases where MP ligand association/dissociation occurs on the time scale of minutes. This research will contribute information about the structure and electronic state changes associated with the ligation of planar and non-planar metal porphyrins with varying occupation of the metal 3d orbitals. Investigations of the connection between porphyrin conformational flexibility and the structural/electronic characteristics of an axially ligated complex are generally applicable to distorted metallo-tetrapyrroles and therefore, relevant to a variety of biologically and biomimetically important processes.Metalloporphyrins perform many versatile functions including light harvesting, electron and energy transfer, catalysis, and act as receptors in molecular recognition. Many of these functions depend on some species (called an axial ligand) interacting with the MP. The attachment of an axial ligand to the MP induces changes in the electronic structure of both the porphyrin and the ligand. Identifying the structural and electronic behavior of the MP during ligation/de-ligation processes is crucial for the understanding of the catalytic and recognition functions of MPs. This project will diverse graduate and undergraduate students in surface science, surface microscopy and spectroscopy, and the basic concepts of coordination chemistry. The proposed research will be used as an educational vehicle for an outreach effort to underrepresented Native American and Hispanic high school students. Mentoring relationships with off-campus science and engineering leaders will provide training, mentorship, and facilitate the formation of collaborative research efforts.

化学司的化学结构，动力学和机制计划支持华盛顿州立大学的Ursula Mazur教授，用于液态固体界面的金属卟啉（MPS）轴向配体配位研究。将对MPS与轴向协调的配体的反应进行系统研究，这些系统中的电子轨道结构和能量将使用扫描隧道显微镜（STM）进行映射。这些研究将测量与配体附着引起的MP平面性的偏差，识别和绘制MP复合物中的金属和配体轨道，比较MP系统的观察到的状态密度以模拟电子计算，并在病例中测量动力学。 MP配体关联/解离时在分钟的时间尺度上发生。这项研究将贡献有关与金属3D轨道不同职业的平面和非平面金属卟啉连接相关的结构和电子状态变化的信息。研究卟啉构象柔韧性与轴突连接络合物的结构/电子特性之间的连接通常适用于扭曲的金属甲基四吡咯，因此，与生物学上和生物规则上重要的多种过程有关。MATALLOPORPHINS.MENTALLOPORPHINS执行许多多功能功能，包括轻度收获，收获的光收获，电子和能量转移，催化和充当分子识别的受体。其中许多功能取决于某些物种（称为轴向配体）与MP相互作用。轴向配体向MP的附着会诱导卟啉和配体的电子结构的变化。在连接/去除过程中识别MP的结构和电子行为对于理解MPS的催化和识别功能至关重要。该项目将在表面科学，表面显微镜和光谱学以及协调化学的基本概念中不同。拟议的研究将被用作教育工具，以进行外展努力，使代表人数不足的美国原住民和西班牙裔高中生。 指导与校外科学和工程领导者的关系将提供培训，指导，并促进合作研究工作的形成。