title: Accurate Theoretical Thermochemistry for Fluoroethyl Radicals.
abstract: An accurate coupled-cluster (CC) based model chemistry was applied to calculate reliable thermochemical quantities for hydrofluorocarbon derivatives including radicals 1-fluoroethyl (CH3-CHF), 1,1-difluoroethyl (CH3-CF2), 2-fluoroethyl (CH2F-CH2), 1,2-difluoroethyl (CH2F-CHF), 2,2-difluoroethyl (CHF2-CH2), 2,2,2-trifluoroethyl (CF3-CH2), 1,2,2,2-tetrafluoroethyl (CF3-CHF), and pentafluoroethyl (CF3-CF2). The model chemistry used contains iterative triple and perturbative quadruple excitations in CC theory, as well as scalar relativistic and diagonal Born-Oppenheimer corrections. To obtain heat of formation values with better than chemical accuracy perturbative quadruple excitations and scalar relativistic corrections were inevitable. Their contributions to the heats of formation steadily increase with the number of fluorine atoms in the radical reaching 10 kJ/mol for CF3-CF2. When discrepancies were found between the experimental and our values it was always possible to resolve the issue by recalculating the experimental result with currently recommended auxiliary data. For each radical studied here this study delivers the best heat of formation as well as entropy data.
authors.affiliation: MTA-BME Lendület Quantum Chemistry Research Group, Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics , Budapest, P.O. Box 91, H-1521 Hungary.
authors.forename: Ádám
authors.initials: Á
authors.lastname: Ganyecz
authors.affiliation: MTA-BME Lendület Quantum Chemistry Research Group, Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics , Budapest, P.O. Box 91, H-1521 Hungary.
authors.forename: Mihály
authors.identifier: http://orcid.org/0000-0003-1080-6625
authors.initials: M
authors.lastname: Kállay
authors.affiliation: MTA-BME Lendület Quantum Chemistry Research Group, Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics , Budapest, P.O. Box 91, H-1521 Hungary.
authors.forename: József
authors.identifier: http://orcid.org/0000-0003-4732-9703
authors.initials: J
authors.lastname: Csontos