Studies on the Hydrogen Transfer Reaction Mechanism of Singlet Thiol Phosphinidene Complex and the Temperature Effect

Abstract

The hydrogen transfer reaction mechanism of the complex of a singlet thiol phosphinidene and a polar molecule hydrogen fluoride (HSP- - - HF) has been investigated at the B3LYP/6-311+G (d,p) level in order to better understand the reactivity of singlet phosphinidene. The results show that the relevant reaction, including step 1 [HSP- - -HF(1) → TS1 (2) → HSPH(F) (3)] and step 2 [HSPH(F) (3) → TS2 (4) → H₂SPF (5)], are very different from the reactions of hydroxyl phosphinidene with hydrogen fluoride. Furthermore, theoretical studies on the thermodynamic and kinetic properties of the reaction have been carried out over the temperature range of 200–1200 K using the DFT/B3LYP method, the general statistical thermodynamics, and Eyring transition state theory with Wigner correction, which is used to examine the temperature effects the reaction channel. It is concluded that step 1 has both thermodynamic and kinetic advantages over step 2, and the high temperature is favorable to step 2. Moreover, the order of lgK and lgk for the steps are consistent with the order of their exoergic energies ΔE and barrier height, but the differences of lgK and lgk for the steps decrease with the temperature increases.

Keywords:

• DFT
• hydrogen transfer reaction mechanism
• singlet thiol phosphinidene
• temperature effects
• thermodynamic and kinetic properties

Acknowledgments

We greatly appreciate the support provided by the Promotional Foundation for the Excellent Middle-Aged and Young Scientists of Shandong Province of China (2007BS08027), the Basic Project of Educational Bureau of Shandong Province of China (J07YA16), the Open Experiments Project, and the Foundation of Innovation Team Building of Ludong University (08-CXB001). We also thank Ludong University Dawning HPC Center for some calculations.