2018

High temperature unimolecular decomposition of cyclopentanone

High temperature unimolecular decomposition of cyclopentanone

B. R. Giri, M. AlAbbad, J. R. Barker, A. Farooq

Proceedings of the Combustion Institute, (2018)
B. R. Giri, M. AlAbbad, J. R. Barker, A. Farooq
Cyclopentanone, Unimolecular decomposition, Ab initio, Carbon monoxide, Laser absorption
2018


Fig. 1G3B3 energies for the major decomposition pathways of cyclopentanone (CPO)
This work reports thermal decomposition of cyclopentanone behind reflected shock waves over 1150 – 1590 K and 750 – 1800 Torr. Carbon monoxide is one of the main reaction products and its formation was monitored using a quantum cascade laser operating near 4.56 µm. Our results show that cyclopentanone undergoes decomposition, under the present experimental conditions, via reaction channels that produce CO almost exclusively. A recent ab initio study by Zaras et al. revealed that cyclopentanone decomposes to produce CO and ethylene by two channels: ring-opening to form a di-radical which subsequently decomposes, and concerted elimination to produce CO and C2H4 directly; their predicted rate constants are much slower than literature experimental data. To resolve the rate constant discrepancy and to determine whether keto-enol tautomerism plays a significant role, we performed master equation simulations which produced results in good agreement both with the previous ab initio study and with the experimental data obtained in the present work.
DOI: 10.1016/j.proci.2018.05.076