Density Functional Theory Study on β-Hydride Elimination as Thermal Decomposition Process of Diethylzinc

Abstract

The β-hydride elimination of diethylzinc (DEZn) is investigated as a decomposition process of DEZn from the viewpoint of quantum chemistry. There are two steps in the β-hydride elimination of DEZn, as we determined from experimental results. Transition states are fully optimized at each β-hydride elimination step, and the energies of these transition states are about 45 kcal/mol higher than their reactants. The products of the two β-hydride elimination steps have higher energies of about 20 kcal/mol than their reactants. These energy profiles agree well with our experimental results indicating that DEZn is decomposed by the two β-hydride elimination steps at 300 and 650 °C and that such decomposition requires thermal energy for the reactions to proceed. On the other hand, about 55 kcal/mol is required to eliminate an ethyl radical from DEZn. Therefore, the main decomposition process of DEZn is β-hydride elimination.