With the support of the Organic Dynamics Program, Professor Vernon D. Parker studies the reactions and energetics of organic radical ions in solution. Professor Parker, of the Department of Chemistry at Utah State University, addresses the influence of coupling between charge and radical centers on the reactivity of one or both of these centers. For example, dimerization rates of arene radical cations are greatly enhanced by methoxy and N,N-dimethylamino substituents which separate the charge and radical centers. Kinetic support for the hypothesis of a correlation between reactivity and extent of coupling is sought through study of radical ions with varying degrees of spin-charge coupling. Professor Vernon D. Parker, of the Department of Chemistry at Utah State University, is supported by the Organic Dynamics Program for his studies of the factors influencing the reactivity of a class of compounds known as radical ions. These compounds, which contain an atom bearing a positive or negative charge (an ion) as well as an atom bearing one less electron than ordinarily found (a radical), often display reactivity distinct from that of a molecule containing only one of these structural elements (radical or ion). Professor Parker is exploring the hypothesis that atomic or molecular groups intervening between the radical and ion centers influence the reactivity of these centers, with those groups providing the greatest `coupling` leading to the most dramatic alteration of reactivity. Radicals and ions appear as important intermediates in a wide variety of chemical and biochemical systems and are additionally significant in areas such as radiation chemistry and toxicology. Professor Parker's studies are leading to the development of a more fundamental understanding of those factors influencing the chemical properties of these important species.
