title: A mechanistic and kinetic study on the decomposition of morpholine.
abstract: The combustion chemistry of morpholine (C(4)H(8)ONH) has been experimentally investigated recently as a representative model compound for O- and N-containing structural entities in biomass. Detailed profiles of species indicate the self-breakdown reactions prevailing over oxidative decomposition reactions. In this study, we derive thermodynamic and kinetic properties pertinent to all plausible reactions involved in the self-decomposition of morpholine and its derived morphyl radicals as a crucial task in the development of comprehensive combustion mechanism. Potential energy surfaces have been mapped out for the decomposition of morpholine and the three morphyl radicals. RRKM-based calculations predict the self-decomposition of morpholine to be dominated by 1,3-intramolecular hydrogen shift into the NH group at all temperatures and pressures. Self-decomposition of morpholine is shown to provide pathways for the formation of the experimentally detected products such as ethenol and ethenamine. Energetic requirements of all self-decomposition of morphyl radicals are predicted to be of modest values (i.e., 20-40 kcal/mol) which in turn support the occurrence of breaking-down reactions into two-heavy-atom species and the generation of doubly unsaturated four-heavy-atom segments. Calculated thermochemical parameters (in terms of standard enthalpies of formation, standard entropies, and heat capacities) and kinetic parameters (in terms of reaction rate constants at a high pressure limit) should be instrumental in building a robust kinetic model for the oxidation of morpholine.
authors: Priority Research Centre for Energy, Faculty of Engineering & Built Environment, The University of Newcastle, Callaghan NSW 2308, Australia. Mohammednoor.Altarawneh@newcastle.edu.au
authors: Mohammednoor
authors: M
authors: Altarawneh
authors: Bogdan Z
authors: BZ
authors: Dlugogorski
mesh_terms: D018533:Biomass; D040761:Biomimetic Materials / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D009025:Morpholines / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D010084:Oxidation-Reduction; D011312:Pressure; D011789:Quantum Theory; D013696:Temperature; D013816:Thermodynamics
chemical_list: D005609:Free Radicals; D009025:Morpholines; D006859:Hydrogen; C037574:morpholine; D009584:Nitrogen