title: Kinetics and thermochemistry of 2,5-dimethyltetrahydrofuran and related oxolanes:  next next-generation biofuels.
abstract: The enthalpies of formation, entropies, specific heats at constant pressure, enthalpy functions, and all carbon-hydrogen and carbon-methyl bond dissociation energies have been computed using high-level methods for the cyclic ethers (oxolanes) tetrahydrofuran, 2-methyltetrahydrofuran, and 2,5-dimethyltetrahydrofuran. Barrier heights for hydrogen-abstraction reactions by hydrogen atoms and the methyl radical are also computed and shown to correlate with reaction energy change. The results show a pleasing consistency and considerably expands the available data for these important compounds. Abstraction by ȮH is accompanied by  formation of both pre- and postreaction weakly bound complexes. The resulting radicals formed after abstraction undergo ring-opening reactions leading to readily recognizable intermediates, while competitive H-elimination reactions result in  formation of dihydrofurans. Formation enthalpies of all 2,3- and 2,5-dihydrofurans and associated radicals are also reported. It is probable that the compounds at the center of this study will be relatively clean-burning biofuels, although  formation of intermediate aldehydes might be problematic.
authors.affiliation: Combustion Chemistry Centre, School of Chemistry, National University of Ireland, Galway, Ireland 091. john.simmie@nuigalway.ie
authors.forename: John M
authors.initials: JM
authors.lastname: Simmie
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D056804:Biofuels; D004988:Ethers, Cyclic / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D006860:Hydrogen Bonding; D007700:Kinetics; D008697:Methane / Q000031:analogs & derivatives / Q000737:chemistry; D008956:Models, Chemical; D015394:Molecular Structure; D011312:Pressure; D013696:Temperature; D013816:Thermodynamics
chemical_list: D000447:Aldehydes; D056804:Biofuels; D004988:Ethers, Cyclic; D005663:Furans; C051333:2,5-dimethyltetrahydrofuran; C051224:methyl radical; D006859:Hydrogen; D008697:Methane