Accurate rate constants for barrierless dissociation of ethanol: VRC-VTST and SS-QRRK calculations with the cheaper DFT method

The rate constants of C-C barrierless bond-fission reaction of ethanol, CH3CH2OH=CH3+CH2OH, are accurately calculated using VRC-VTST and SS-QRRK. The multi-reference method, CASPT2(2e,2o)/ccpVTZ, is used to ob-tain the minimum energy profile, which serves as the benchmark to evaluate the feasibility of different density functional theory methods in describing this bond dissociation. The M06-2X/cc-pVTZ method is selected for rate constant calculations due to its best performance. The good agreement between our calculations and experimental measurements demonstrates the feasibility of DFT method for VRC-VTST calculation with both high efficiency and reasonable accuracy for the barrierless bond-fission reaction.

Automated summary

The rate constants of the C-C barrierless bond-fission reaction of ethanol have been accurately calculated using VRC-VTST and SS-QRRK. The CASPT2(2e,2o)/ccpVTZ multi-reference method is utilized to obtain the minimum energy profile and evaluate the feasibility of different density functional theory methods. The M06-2X/cc-pVTZ method is selected for rate constant calculations due to its superior performance.