An investigation of the extent of charge development in the reactions of substituted N-phenylhydroxylamines with methyl and benzylarenesulfonates will be conducted. The extent of charge development in the transition state will be evaluated by measuring reaction rates as a function of free energy parameters for both the nucleophile (N-phenylhydroxylamines) and the substrate (arenesulfonates). Kinetic isotope effects will be used to provide details about the extent of bonding in the transition state. The degree of charge development in the transition state derived experimentally will be compared with results from semi-empirical molecular orbital calculations. The study will combine electrochemical and spectroscopic techniques with molecular orbital calculations and kinetic isotope measurements to determine the role that solvent and substrate type play in defining the role of N-hydroxyl groups on nucleophilic substitution reactions of amines. %%% This grant from the Organic Dynamics Program supports an investigation of nucleophilic reactions between N-hydroxylamines and arenesulfonates by Professor K. R. Fountain at Northeast Missouri State University. The investigation will focus on the unusual effect that certain hydroxy groups have on the rate of chemical reactions involving amines. A particularly important feature of this work will be an involvement of undergraduate chemistry majors in a research project combining spectroscopic and electrochemical laboratory measurements with theoretical calculations on a computer. By simulating the reactions on a computer, and comparing the results with the experimental data, it will be possible to delineate the degree to which transfer of an electron between the interacting chemical species accelerates the overall rate of the nucleophilic reactions being studied.
