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The unimolecular decomposition of dimethoxymethane: channel switching as a function of temperature and pressure

Pazdera, Tobias M. 1; Wenz, Johannes 1; Olzmann, Matthias 1
1 Institut für Physikalische Chemie (IPC), Karlsruher Institut für Technologie (KIT)

Abstract:

Branching ratios of competing unimolecular reactions often exhibit a complicated temperature and pressure dependence that makes modelling of complex reaction systems in the gas phase difficult. In particular, the competition between steps proceeding via tight and loose transition states is known to present a problem. A recent example from the field of combustion chemistry is the unimolecular decomposition of CH$_3$OCH$_2$OCH$_3$ (DMM), which is discussed as an alternative fuel accessible from sustainable sources. It is shown by a detailed master equation analysis with energy- and angular-momentum-resolved specific rate coefficients from RRKM theory and from the simplified statistical adiabatic channel model, how channel switching of DMM depends on temperature and pressure, and under which experimental conditions which channels prevail. The necessary molecular and energy data were obtained from quantum-chemical calculations at the CCSD(F12*)(T*)/cc-pVQZ-F12//B2PLYP-D3/def2-TZVPP level of theory. A parameterization describing the channel branching over extended ranges of temperature and pressure is derived, and the model is used to simulate shock tube experiments with detection by atomic resonance absorption spectroscopy and time-of-flight mass spectrometry. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000149248
Veröffentlicht am 01.08.2022
Originalveröffentlichung
DOI: 10.1039/D2FD00039C
Scopus
Zitationen: 4
Web of Science
Zitationen: 3
Dimensions
Zitationen: 4
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Physikalische Chemie (IPC)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2022
Sprache Englisch
Identifikator ISSN: 1359-6640, 0301-7249, 1364-5498, 2050-8417
KITopen-ID: 1000149248
Erschienen in Faraday Discussions
Verlag Royal Society of Chemistry (RSC)
Band 238
Seiten 665-681
Nachgewiesen in Scopus
Dimensions
Web of Science
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