“Thermal Decomposition of 2-Methyltetrahydrofuran Behind Reflected Shock Waves Over the Temperature Range of 1179-1361 K”
B. Rajakumar, A. Parandaman and M. Balaganesh. J. Phys. Chem. A. 2021.(Just Accepted!)

The thermal unimolecular decomposition of 2-Methyltetrahydrofuran (2-MTHF) was studied behind reflected shock waves in a single-pulse shock tube over the temperature range of 1179-1361 K and pressure range of 9-17 atm. Methane, ethylene, ethane, 1,3-butadiene, propylene, acetaldehyde, and acetylene were identified as products in the decomposition of 2-MTHF. A reaction scheme was proposed to explain the mechanism for the observed products. The experimentally determined rate coefficients were best fit to an Arrhenius expression for the overall decomposition and are represented as k(expt,1179-1361 K) = (3.23 ± 0.59) × 1011 (s-1) exp (-51.3±1.4 kcal mol-1/RT). Quantum chemistry methods were used to calculate the energetics and kinetics of various possible unimolecular dissociation pathways involved in the thermal decomposition of 2-MTHF. The initial decomposition of 2-MTHF occurs predominantly via ring-methyl (C-CH3) single bond fission leading to the formation of tetrahydrofuran (C4H7O) radical and methyl radical was found to be a major reaction compared to all the possible initial bond fission, ring-opening, and molecular elimination channels. The temperature dependent rate coefficients for the unimolecular dissociation of 2-MTHF were calculated using RRKM theory in combination with CCSD(T)/cc-pVTZ//B3LYP/cc-pVTZ level of electronic structure calculations over the temperature range of 800-1500 K. The computed high-pressure limiting rate coefficients for the initial decomposition of 2-MTHF through C-CH3 single bond fission channel were found to be ~2 times higher in the temperatures between 800 and 900 K, above this temperature, they agree well with the values reported in the literature.