Session: COMP Poster Session:

Catalysis plays an important role in many environmental and industrial applications such as ozone decomposition, oxidative removal of mercury, carbon monoxide oxidation, and selective propene oxidation. Experimental studies using a selected-ion drift cell reactor have demonstrated that gold-halide cations, AuX⁺ (X=Br, I), can activate sigma bonds in CH₃X and CF₃X. To explore the reactivity of these species, density functional theory (B3LYP/def2-TZVPP) is used to identify unknown structures and map electronic potential energy surfaces. This level of theory is validated against experimental bond dissociation energies of similar species. To test the efficiency of gold as a catalyst, this computational approach is used to model reactions of AuX⁺ species with a neutral CH₃X or CF₃X compound. The structures of the most likely products and viable reaction pathways are identified based on optimized geometries and zero-point energy corrected potential energy surfaces, respectively. There are a number of different reactions between AuX⁺ and CH₃X or CF₃X to be examined, specifically halogen elimination, halogen switching, and charge transfer between species. When looking at the reaction of AuBr⁺ with CH₃I or CF₃I, both reactions formed products that showed halogen elimination and halogen switching. However, a new product was formed in the CF3I reaction that was not seen in the CH₃I reaction, where CF3⁺ was created and Br-Au-I is predicted as the neutral product required for an overall exothermic process.

Makenzie Long

University of Central Arkansas

Appearances