Direct Observational Studies of Carbenes

罗格斯大学的罗伯特·莫斯博士获得了有机和高分子化学方面的资助。这项工作主要集中在对卡宾的直接观测研究，卡宾是有机化学中一类重要的反应中间体。它们之所以重要，是因为它们具有不同寻常的反应性，这是因为卡宾是缺电子的，可以以多种可访问的电子态存在。卡宾和其他高活性中间体的基础研究将通过直接光谱观察和绝对动力学方法进行。二氮杂卤化物交换反应将用于合成新型的二甲氧基卡宾和氟甲氧基卡宾的前体。对于二甲氧基卡宾，光谱、绝对动力学、活化参数和反应性研究将定义这种典型的亲核卡宾的行为。将对氟甲氧基卡宾进行平行研究。对卡宾/烯烃加成反应的活化能进行了测定和分析。其他要研究的卡宾包括甲氧基卡宾、氟甲基卡宾和二甲氨基甲氧基卡宾。还将测量苯基卤代卡宾与受阻烯烃的加成反应的活化参数，在这些反应中已经观察到异常行为。最后，我们将研究由二氮杂环和卡宾生成碳正离子的几种方法。

This grant in Organic and Macromolecular Chemistry provides support for the research of Dr. Robert Moss, Rutgers University. The work is focused on the direct observational studies of carbenes, which are a class of important reaction intermediates in organic chemistry. They are important because of their unusual reactivity which arises because carbenes are electron deficient and can exist in more than one accessible electronic state. Fundamental studies of carbenes and other highly reactive intermediates will be carried out by direct spectroscopic observation and absolute kinetic methods. The diazirine halide exchange reaction will be used to prepare novel diazirine precursors for dimethoxycarbene and fluoromethoxycarbene. For dimethoxycarbene, spectroscopic, absolute kinetic, activation parameter, and reactivity studies will define the behavior of this representative nucleophilic carbene. Parallel studies will be made with fluoromethoxycarbene. The free energies of activation of the carbene/alkene addition reactions will be determined and analyzed for enthalpy/entropy partition. Other carbenes to studied include methoxymethylcarbene, fluoromethylcarbene, and dimethylaminomethoxycarbene. Activation parameters will also be measured for additions of phenylhalocarbenes to hindered alkenes, where unusual behavior has already been observed. Finally, several methods of generating carbonium ion from diazirines and carbenes will be studied.