Carbanions and Physical Organic Chemistry

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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.