Carbanions and Physical Organic Chemistry

实验和计算方法将用于确定各种碳氢化合物的动态酸度。实验方法将包括用氚核磁共振测定铯和锂环己胺催化的n -t环己胺的交换率。用质谱和氘核磁共振测定与环己胺- n -d2交换氘的速率。对各种碳氢化合物和碱之间的质子转移反应进行理论计算，并与实验结果进行比较。离子对SN2置换反应的计算将继续进行。这些反应表现出不同寻常的高弯曲过渡态，并可能产生不同于相应离子反应的相对反应活性。这项来自有机动力学项目的资助将用于支持加州大学伯克利分校的Andrew Streitwieser教授的持续工作。极弱酸性碳氢化合物的酸度将由最近开发的灵敏技术来测定。这将扩展一个重要的知识体系。将对碳氢化合物的酸度进行理论计算，并将计算结果与实验结果进行比较。这项工作将为弱酸性烃及其碳氢键的化学反应性提供一个基本的认识。本文将对有机化学中一种基本的位移反应过程进行附加计算。初步的计算表明，在这个反应过程中有一个不寻常的几何形状，这项工作将继续下去。

Experimental and computational methods will be applied to determine the kinetic acidities of a variety of hydrocarbons. Experimental methods will include the determination of exchange rates from cyclohexylamine-N-t catalyzed by cesium and lithium cyclohexylamides by tritium NMR. Some rates will be determined for deuterium exchange with cyclohexylamine-N-d2 using mass spectroscopy and deuterium NMR. Theoretical calculations will be carried out for proton transfer reaction between various hydrocarbons and bases, and compared to experimental results. Calculations of ion-pair SN2 displacement reactions will be continued. These reactions show unusual highly bent transition states and may give relative reactivities different from the corresponding ionic reactions. %%% This grant from the Organic Dynamics Program supports the continuing work of Professor Andrew Streitwieser at the University of California, Berkeley. The acidity of very weakly acidic hydrocarbons will be determined by recently developed sensitive techniques. This will extend an important body of knowledge. Theoretical calculations will be made that relate to the acidity of hydrocarbons and the results will be compared to the experimental findings. This work will provide a fundamental understanding of weakly acidic hydrocarbons and the consequences to chemical reactivity of the carbon-hydrogen bond in hydrocarbons. Additional calculations will be carried out on a fundamental displacement reaction process in organic chemistry. Preliminary calculations have shown an unusual geometry in the course of this reaction and this work will be continued.