A theoretical study of the original Shilov reaction involving methane activation by platinum tetrachloride (PtCl42-) in an acidic aqueous solution

摘要

Density functional theory (DFT) has been employed to investigate the rate-determining step for the Shilov reaction in which ptCl(4)(-2) 4 can catalyze H-D exchange of alkanes in acidic aqueous solution. C-H activation and methane uptake are the two possible candidates. Associative and dissociative pathways are both considered in the methane uptake step. It was not possible to determine whether methane uptake followed an associative or dissociative mechanism due to uncertainties in the calculated contributions to the free energy of activation, from entropy and solvation. The active species in the Shilov reaction are PtCl42-, PtCl3H2O- and PtCl2(H2O)(2). We have shown that PtCl2(H2O)(2) is the most active catalyst for H/D exchange. Rate expressions for the Shilov reaction have been derived for different reaction conditions. (c) 2006 Elsevier B.V. All rights reserved.