Theoretical Study on the Dynamics and Kinetics of the Reaction of CH₂OH with OH

Abstract

The stochastic one-dimensional chemical master equation (CME) simulation method was used to investigate the dynamics of the reaction of CH2OH with OH. A multiwell multichannel potential energy surface (PES) was constructed at the CCSD­(T)/Aug-cc-pVTZ//CBS-QB3 and QCISD­(T)/Aug-cc-pVTZ//CBS-QB3 levels of theory. The constructed PES consisted of three chemically activated intermediates and two van der Waals complexes. The fractional population analysis unraveled the role of the energized intermediates and van der Waals complexes in the early stages of this complex reaction. The CME calculations provided the phenomenological rate constants through analysis of the eigenvalues and eigenvectors of collision matrices while Leonard-Jones potential was used to model the collisions. The CME results indicated that CH2O and H2O were the major products, in accordance with the literature. Also, the findings declared the temperature and pressure independence of the reaction over a wide range of temperature (250 to 2400 K) and pressure (0.1 to 7 atm). Furthermore, the efficiency of tunneling on the hydrogen transfer isomerization reaction of trans-HCOH to CH2O was confirmed over the temperature range of 250 to 3000 K. The rate constants for different reaction channels are reported.

The kinetics and dynamics of the multichannel multiwell reaction of CO(1Σ+) with OH(2Π): theoretical investigation

“…The T1 values for the all stationary points in the PES (the reactants, products and transition states) of the title reaction are given in Table 2. The T1 diagnostic value for all structures except HCO 2 species, which according to our following discussion doesn't play an important role in kinetics and dynamics of this system, was found to be less than 0.03, indicating that single-reference calculations can be used reliably to characterize the present reactive system [78,79]. Therefore, this method is sufficient accuracy to use for this system.…”