A quantum mechanical study of the abstraction reactions of fused bicyclic dimetallenes.
The potential energy surfaces for the abstraction reactions of fused bicyclic dimetallene species with carbon tetrachloride have been characterized in detail by using density functional theory including zero-point corrections. All the stationary points were determined at the B3LYP/LANL2DZdp level of theory. Five fused bicyclic dimetallene species including fused bicyclic diethylene, fused bicyclic disilene, fused bicyclic digermene, fused bicyclic distannene, and fused bicyclic diplumbene have been chosen in this work as model reactants. Comparisons of the activation barriers and reaction enthalpies were used to determine the relative reactivity of the fused bicyclic dimetallenes on the reaction potential energy surface. As a result, our theoretical investigations suggest that, irrespectively of the fused bicyclic dimetallene, the Cl-abstraction pathway is more favorable than the CCl3-abstraction pathway from both kinetic and thermodynamic considerations. Moreover, our model calculations indicate that the heavier the group 14 element in the fused bicyclic dimetallenic species, the lower the activation barrier and the more exothermic the haloalkane abstraction. Furthermore, a configuration mixing model based on the work of Pross and Shaik is used to rationalize the computational results. The results obtained allow a number of predictions to be made.
Hsiao
Jun
J
Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan.
Ming-Der Su
Ming-Der
MD