Transient Intermediates of Chemical Reactions

化学反应的瞬时中间体

• 批准号: 0090930
• 负责人: Frantisek Turecek
• 金额: $ 35.4万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-15 至 2004-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0090930&HistoricalAwards=false
• 关键词: Transient; Intermediates; Chemical; Reactions

Professor Frantisek Turecek, of the Department of Chemistry at the University of Washington, is supported by the Organic and Macromolecular Chemistry Program for his research on transient intermediates of chemical reactions in the gas phase. The objectives of the proposed research are to (1) generate in the gas phase elusive and highly reactive radicals relevant to the high-energy chemistry of peptides, nucleic acids, and organometallic compounds, (2) investigate the stabilities, dissociation kinetics, and photoexcitation of the transient species, and (3) use high-level quantum chemistry calculations combined with RRKM theory to obtain relative, dissociation, and activation energies for the transient intermediates and gauge the dissociation kinetics. The basic experimental method is neutralization-reionization mass spectrometry (NRMS), using a "non-chemical" means to generate transient species. In NRMS the short interaction time between ion and target results in maintaining both bond connectivity and geometry in the nascent neutral species generated. New methods are proposed to extend the NRMS methodologies to study transient intermediates from polar compounds and allow for measurements of fast dissociations. The potential impact of these studies is in providing new insights into the complex chemistries of highly reactive polyatomic species that are formed transiently by high-energy processes. These studies, complemented by computational analyses, address the stabilities and reactivity of these transient intermediates, shedding light on the fundamental events that occur during high-energy processes.The reaction of atmospheric oxygen with molecules containing sulfur occurs on a scale of one million tons per year globally making it of considerable environmental importance. With the support of the Organic and Macromolecular Chemistry Program Professor Frantisek Turecek will generate and study in the laboratory the many products from these and related reactions. In addition to studying these smaller molecules that are of great significance to the environment and sustaining life on this planet, Professor Turecek's research focuses on larger molecular systems relevant to nucleic bases. Radicals derived from nucleic bases are presumed to occur as short lifetime species that can cause the modification of RNA and DNA, especially in radiation damage caused by exposure to sunlight, background radiation, or other high-energy processes. Characterization of transient intermediates represents a formidable challenge to the experimental and theoretical methods of chemistry. This inquiry into the processes and dynamics of transient intermediates has the potential for practical usefulness in peptide sequencing.

华盛顿大学化学系的Frantisek Turecek教授得到了有机和大分子化学计划的支持，用于研究天然气阶段化学反应的短暂性中间体。 The objectives of the proposed research are to (1) generate in the gas phase elusive and highly reactive radicals relevant to the high-energy chemistry of peptides, nucleic acids, and organometallic compounds, (2) investigate the stabilities, dissociation kinetics, and photoexcitation of the transient species, and (3) use high-level quantum chemistry calculations combined with RRKM theory to obtain relative, dissociation, and瞬态中间体的激活能并衡量解离动力学。基本的实验方法是使用“非化学”手段进行瞬态物种的中和质谱法（NRMS）。在NRMS中，离子和靶标之间的短相互作用会导致在产生的新生中性物种中保持键连通性和几何形状。提出了新的方法来扩展NRMS方法，以研究来自极性化合物的瞬时中间体，并允许测量快速解离。这些研究的潜在影响在于为高度反应性多原子物种的复杂化学物质提供新的见解，这些化学物质是由高能过程瞬时形成的。这些研究在计算分析中得到补充，解决了这些瞬时中间体的稳定性和反应性，从而阐明了在高能过程中发生的基本事件。大气氧与含硫的分子的反应发生在每年的一百万吨全球范围内，使全球范围内的一百万吨，使其具有相当大的环境重要性。在有机和大​​分子化学计划的支持下，教授Frantisek Turecek将在实验室中产生和研究这些和相关反应的许多产品。除了研究这些较小的分子对环境和维持这个星球上的生命具有重要意义的较小分子外，Turecek教授的研究还集中在与核基碱基相关的较大分子系统上。假定源自核碱基的自由基是作为可能导致RNA和DNA修饰的短寿命物种发生的，尤其是在暴露于阳光，背景辐射或其他高能过程中引起的辐射损伤中。瞬态中间体的表征代表了对化学实验和理论方法的巨大挑战。对瞬态中间体的过程和动力学的调查具有实用性在肽测序中的潜力。