Maria Szczesniak-Bryant and Grzegorz Chalasinski of Oakland University are supported by a grant from the Theoretical and Computational Chemistry Program to study, using ab initio theory, the effect of the long-range region of potential energy surfaces on chemical reactions. The specific reactions that are to be studied are those of chlorine atoms with hydrogen molecules and hydrogen chloride and hydroxyl radicals with hydrogen molecules. This variously includes open-shell atoms and open and closed shell diatomic molecules, in the open shell cases involving multiple surfaces. The influence of the different components of the interaction energy (electrostatic, exchange, induction and dispersion) will be investigated to determine the physical origin of the interactions and to understand the influence of the early stages of a chemical reaction on the overall reactivity.
The way chemicals react is controlled by the energy of the interaction between the reacting species, and between the product species, and thus is of general importance to much of chemistry. Here the interaction at large distances will be explored theoretically to determine its influence on the overall reactivity by orienting the species or trapping them prior to overcoming barriers.