Reactions of Cu+(1S, 3D) with CF3X (X=Cl, Br, I)

CHED 1023

Scott R. Musial,, William S. Taylor,, and Micah L. Abrams, Department of Chemistry, University of Central Arkansas, Laney Hall, Conway, AR 72035
State-specific reactions of Cu+(1S) and Cu+(3D) with CF3X (X = Cl, Br, I) have been carried out in a selected-ion drift cell apparatus. Cu+(1S) participates in association exclusively with all three of these neutrals, whereas Cu+(3D) abstracts X to yield CuX+, which subsequently abstracts X- in a secondary step. All bimolecular processes are consistent with known thermochemical and quantum mechanical requirements. Kinetic studies reveal that CF3Cl reacts with Cu+(3D) at approximately 7% of the ADO rate, indicating a kinetic barrier to reaction. By comparison, CF3Br and CF3I react at essentially the ADO limit with this Cu+ state suggesting the possibility that significant mechanistic differences may exist between CF3Cl and the other two neutrals despite analogous product formation. Quantum chemical calculations have been employed to determine the stationary points along the reaction coordinate of Cu+(3D) with CF3X in an effort to explain differences in the observed rates of reaction and shed light on possible reaction mechanisms.