GEOMETRIC AND ELECTRONIC STRUCTURAL STUDIES OF TRANSITION METAL DITHIOLENES

过渡金属二硫烯的几何和电子结构研究

• 批准号: 8362159
• 负责人: Stephen A Sproules
• 金额: $ 1.62万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8362159
• 关键词: Active Sites; Biochemical Reaction; Chemistry; Complex; Data; Devices; Electronics; Enzymes; Funding; Grant; Inorganic Chemistry; Lasers; Ligands; Measures; Metals; Metric; Molybdenum; National Center for Research Resources; Optics; Oxidation-Reduction; Principal Investigator; Production; Radiation; Research; Research Infrastructure; Resources; Science; Selenium; Source; Spectrum Analysis; Sulfur; System; Transition Elements; Tungsten; United States National Institutes of Health; absorption; base; cost; density; design; electronic structure; fascinate; insight; interest; metal complex; multiplet; oxidation; physical property; research study; sensor; solid solution; structural biology

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Tris(dithiolene) transition metal complexes have piqued considerable interest in inorganic chemistry due to their fascinating physical properties and electronic structures. Moreover, tris(dithiolene) complexes were the first discrete molecules to possess trigonal prismatic geometry, a feature observed in the oxidized active sites of several molybdenum and tungsten enzymes that catalyze a wide variety of fundamental biochemical reactions. In material sciences, certain dithiolene complexes are candidate materials for nonlinear optical devices and laser applications due to their enormous absorption bands in the near-infrared region. Their reversible redox chemistry has been utilized in the production of semi- and superconducting materials and sensors. The understanding of enzymatic reaction mechanisms or the design of new functional materials should be based on a thorough understanding of the electronic structures of such compounds. Dithiolene ligands can exist as radicals and diradicals and are described as ?non-innocent?, which makes the oxidation and spin states of the central metal ambiguous and difficult to determine experimentally. The existence of oxidized diselenolene ligands is still unknown. Thus, x-ray absorption spectroscopy at the metal K-, and L-edges as well as the sulfur and selenium K-edges is ideally suited to provide fundamental electronic structure insights into the function of these systems. Additionally, metal and ligand EXAFS will assist in defining metric parameters in the solid and solution state. Sulfur and selenium EXAFS are perfectly poised to gauge the geometric change from trigonal prismatic to octahedral as the complex is sequentially reduced by measuring interligand distances. The experiments will be combined with quasi-relativistic density functional as well as multiplet calculations in order to obtain more insight into the experimental data.

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 子项目的主要研究者可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 三（二硫戊烯）过渡金属配合物由于其独特的物理性质和电子结构，在无机化学中引起了人们极大的兴趣。此外，三（二硫杂环戊烯）复合物是第一个离散的分子，拥有三角棱柱的几何形状，观察到的几个钼和钨酶，催化各种各样的基本生化反应的氧化活性位点的功能。在材料科学中，某些二硫纶配合物由于其在近红外区域的巨大吸收带而成为非线性光学器件和激光应用的候选材料。它们的可逆氧化还原化学已被用于生产半超导和超导材料和传感器。对酶反应机制的理解或新功能材料的设计应基于对此类化合物电子结构的透彻理解。二硫纶配体可以自由基和双自由基存在，并被描述为？非无辜的？这使得中心金属的氧化和自旋状态不明确，并且难以通过实验确定。氧化二硒烯配体的存在仍然是未知的。因此，在金属K-和L-边缘以及硫和硒K-边缘处的X射线吸收光谱非常适合于提供对这些系统的功能的基本电子结构的见解。此外，金属和配体EXAFS将有助于确定在固体和溶液状态的度量参数。硫和硒的EXAFS是完美的准备来衡量几何变化，从三角棱柱八面体的复杂的是通过测量配体间的距离依次减少。实验将结合准相对论密度泛函以及多重态计算，以获得更多的洞察实验数据。