A quantum-chemical study of hydride transfer in catalytic transformations of paraffins on zeolites. Pathways through adsorbed nonclassical carbonium ions

A quantum-chemical investigation of the hydride transfer reaction in catalytic transformations of hydrocarbons on zeolites has been performed. Ab initio calculations at the MP2/6-31++G**//HF/6-31G* level demonstrated that the activated complexes of hydride transfer reaction in catalytic transformations of paraffins on zeolites very much resemble adsorbed nonclassical carbonium ions. However, these transient species are strongly held at the surface active sites by the Coulomb interaction. The calculated activation energies for reactions involving propane and isobutane are in a reasonable agreement with the experimental data.