DFT and ab initio study on mechanism of olefin hydroalumination by XAlBui2 in the presence of Cp2ZrCl2 catalyst. III. Efficiency of transmetallation in Cp2ZrRCl–XAlBui2 system

Abstract Transmetallation leading to formation of n -Pr–Al bond in the Cp 2 Zr( n -Pr)Cl–XAlBu i 2 (X = H, Cl, Bu i ) couple was studied using PBEPBE/3ζ and RI-MP2/Λ2//PBEPBE/3ζ approaches. Calculation results were corrected by taking into account of nonspecific solvent effect (toluene). Depending on the nature of organoaluminum compound, either decomposition of alkylalane self-associates (HAlBu i 2 and ClAlBu i 2 cases) or alkyl group transfer reaction from Zr to Al atom (AlBu i 3 case) could be a rate-determining step of the process. The modeling of kinetics with calculated Gibbs free energies for elementary steps of the process shows that transmetallation rates decrease in the following order: ClAlBu i 2  > HAlBu i 2  >> AlBu i 3 .