Absolute Kinetic Studies of Carbene Reactions

卡宾反应的绝对动力学研究

• 批准号: 9109044
• 负责人: Robert Moss
• 金额: $ 35万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-01-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9109044&HistoricalAwards=false
• 关键词: Absolute; Kinetic; Studies; Carbene; Reactions

A study of carbenes and related reactive intermediates by laser flash photolysis will be conducted. Spectroscopic and kinetic measurements of these highly reactive intermediates in solution will be made. The research projects will include investigation of: (1) the properties of nucleophilic carbenes; (2) the kinetics of carbene/metal salt reactions (carbenoid formation); (3) the properties of "push pull" carbenes as well as pyridyl and pyridinium carbenes; (4) the effects of fluoro and methoxy substituents in modulating intramolecular carbene rearrangements; and (5) the fragmentation of oxycarbenes to carbocations. These studies will be of particular importance in providing insight and understanding for reactions that are characterized by low activation energy barriers. %%% This grant from the Organic Dynamics Program supports the continuing work of Professor Robert A. Moss at Rutgers University. These studies will be centered around the production and reactions of carbenes, which are species that contain a carbon atom with two formal bonds rather than four bonds as found in stable carbon compounds. Carbenes are reactive intermediates that are very short-lived. Special flash laser techniques will be employed to observe these reactive intermediates and to study the rate at which they react. Carbenes can undergo reaction to give other reactive intermediates. For example, carbenes can react with lithium chloride to generate an adduct called a carbenoid with the normal complement of four bonds. With appropriate substitution, carbenes can give another reactive intermediate, a carbocation, which contains a carbon with three bonds and a net one unit of positive charge. These reactions will provide a means to study some of the important reactive intermediates in organic chemistry.

本文将对激光闪光光解羰基化合物及相关反应中间体进行研究。在溶液中对这些高活性中间体进行光谱和动力学测量。研究项目包括：(1)亲核碳烯的性质；(2)卡宾/金属盐反应动力学（类卡宾生成）；(3)“推挽”卡宾、吡啶卡宾和吡啶卡宾的性质；(4)氟取代基和甲氧基取代基在调节分子内碳重排中的作用；(5)氧羰基分裂成碳正离子。这些研究对于提供对以低活化能垒为特征的反应的认识和理解具有特别重要的意义。这项来自有机动力学项目的资助将支持罗格斯大学Robert A. Moss教授的持续研究。这些研究将集中在碳烯的产生和反应上，碳烯是一种含有两个形式键的碳原子，而不是稳定碳化合物中的四个键。卡宾是一种活性中间体，寿命很短。将采用特殊的闪光激光技术来观察这些反应中间体并研究它们的反应速率。卡贝烯可以发生反应生成其他活性中间体。例如，碳烯可以与氯化锂反应生成一种被称为类碳烯的加合物，具有四个键的正常补体。通过适当的取代，碳烯可以得到另一种活性中间体，即碳正离子，碳正离子含有一个有三个键的碳和一个单位的正电荷。这些反应将为研究有机化学中一些重要的反应中间体提供一种手段。