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.

将通过激光闪光光解对卡宾和相关反应中间体进行研究。将对溶液中这些高反应性中间体进行光谱和动力学测量。研究项目将包括以下方面的研究：（1）亲核卡宾的性质； (2) 卡宾/金属盐反应动力学（类卡宾形成）； (3)“推拉”卡宾以及吡啶基和吡啶鎓卡宾的性质； (4)氟和甲氧基取代基在调节分子内卡宾重排中的作用； (5)氧卡宾裂解为碳正离子。这些研究对于提供对以低活化能垒为特征的反应的洞察和理解特别重要。 %%% 有机动力学计划的这笔赠款支持罗格斯大学 Robert A. Moss 教授的持续工作。这些研究将集中在卡宾的生产和反应上，卡宾是含有两个正式键的碳原子的物质，而不是稳定碳化合物中发现的四个键。卡宾是活性中间体，寿命非常短。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。 卡宾可以发生反应生成其他活性中间体。例如，卡宾可以与氯化锂反应生成一种称为类卡宾的加合物，其具有四个键的正常补数。通过适当的取代，卡宾可以得到另一种反应中间体，即碳正离子，其中包含具有三个键的碳和一个净正电荷单位。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。