RT Journal Article
T1 Crossed molecular beam experiments and theoretical simulations on the multichannel reaction of toluene with atomic oxygen
A1 Recio Ibáñez, Pedro
A1 Balucani, Nadia
A1 Vanuzzo, Gianmarco
A1 Caracciolo, Adriana
A1 Rosi, Marzio
A1 Cavallotti, Carlo
A1 Baggioli, Alberto
A1 Della Libera, Andrea
A1 Casavecchia, Piergiorgio
AB Despite extensive experimental and theoretical studies on the kinetics of the O(3P) + C7H8 (toluene) reaction and a pioneering crossed molecular beam (CMB) investigation, the branching fractions (BFs) of the CH3C6H4O(methylphenoxy) + H, C6H5O(phenoxy) + CH3, and spin-forbidden C5H5CH3 (methylcyclopentadiene) + CO product channels remain an open question, which has hampered the proper inclusion of this important reaction in the chemical modelling of various chemical environments. We report a CMB study with universal soft electron-ionization mass-spectrometric detection of the reactions O(3P,1D) + toluene at the collision energy of 34.7 kJ mol−1. From CMB data we have inferred the reaction dynamics and quantified the BFs of the primary products and the role of intersystem crossing (ISC). The CH3-elimination channel dominates (BF = 0.69 ± 0.22) in the O(3P) reaction, while the H-displacement and CO-formation channels are minor (BF = 0.22 ± 0.07 and 0.09 ± 0.05, respectively), with ISC accounting for more than 50% of the reactive flux. Synergistic transition-state theory (TST)-based master equation simulations including nonadiabatic TST on ab initio coupled triplet/singlet potential energy surfaces were employed to compute the product BFs and assist in the interpretation of the CMB results. In the light of the good agreement between the theoretical predictions for the O(3P) + toluene reaction and the CMB results as well as the absolute rate constant as a function of temperature (T) (from literature), the so-validated computational methodology was used to predict channel-specific rate constants as a function of T at 1 atm.
PB Royal Society of Chemistry
SN 1359-6640
SN 1364-5498
YR 2024
FD 2024-02-19
LK https://hdl.handle.net/20.500.14352/131303
UL https://hdl.handle.net/20.500.14352/131303
LA eng
NO N. Balucani, et al. Crossed molecular beam experiments and theoretical simulations on the multichannel reaction of toluene with atomic oxygen. Faraday Discuss., 2024,251, 523-549
NO Received 22nd December 2023, Accepted 19th February 2024Work supported by MUR through PRIN 2017 Prot. 2017PJ5XXX (MAGIC DUST). We acknowledge financial support under the National Recovery and Resilience Plan (NRRP), Mission 4, Component 2, Investment 1.1, Call for tender No. 104 published on 02.02.2022 by the Italian Ministry of University and Research (MUR), funded by the European Union \u2013 NextGenerationEU \u2013 Project Title 20227W5CLJ Biomass gasification for hydrogen production (Bio4H2) \u2013 CUP J53D23001970006 \u2013 Grant Assignment Decree No. 961 adopted on 30.06.2023 by the Italian Ministry of University and Research (MUR) and Call for tender No. 1409 published on 14.09.2022 by the Italian Ministry of University and Research (MUR), funded by the European Union \u2013 NextGenerationEU \u2013 Project Title P20223H8CK Degradation of space-technology polymers by thermospheric oxygen atoms and ions: an exploration of the reaction mechanisms at an atomistic level (ThermOPoly) \u2013 CUP J53D23014440001 \u2013 Grant Assignment Decree No. 1386 adopted on 01.09.2023 by the Italian Ministry of University and Research (MUR).
NO Italian Ministry of University and Research
NO European Union
DS Docta Complutense
RD 17 mar 2026