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  • 1.
    Agback, M
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry.
    Lunell, S
    Hussenius, A
    Matsson, O
    Theoretical studies of proton transfer reactions in 1-methylindene1998In: ACTA CHEMICA SCANDINAVICA, ISSN 0904-213X, Vol. 52, no 5, p. 541-548Article in journal (Other scientific)
    Abstract [en]

    The base-catalysed 1,3-proton transfer reactions in 1-methylindene have been studied theoretically in polar (water) and unpolar (cyclohexane) solvents, respectively, for two different choices of bases, namely ammonia and trimethylamine (TMA), using the SM

  • 2.
    Borg, O. Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Karlsson, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Isomäki-Krondahl, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Davidsson, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Predissociation of Chlorobenzene, beyond the pseudo-diatomic model2008In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 456, no 4-6, p. 123-126Article in journal (Refereed)
    Abstract [en]

    Dissociation of chlorobenzene via the lowest singlet excited state has been investigated by means of pump-probe femtosecond spectroscopy and spin-orbit corrected ab initio quantum chemistry. We have found that the so far accepted model with a (1)pi pi* -> (3)pi/n sigma* reaction mechanism has to be amended. We suggest that the mechanism goes via a transition from (1)pi pi* to a pi sigma* state that is to 90% a singlet. Further, three nuclear degrees of freedom required to describe the dissociation have been defined.

  • 3.
    Borg, O Anders
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Chemical Physics. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry. Avdelningen för kvantkemi.
    Liu, Ya-Jun
    Persson, Petter
    Lunell, Sten
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Chemical Physics. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry. Avdelningen för kvantkemi.
    Karlsson, Daniel
    Department of Photochemistry and Molecular Science. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Chemical Physics.
    Kadi, Malin
    Davidsson, Jan
    Department of Photochemistry and Molecular Science. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Chemical Physics.
    Photochemistry of bromofluorobenzenes.2006In: J Phys Chem A Mol Spectrosc Kinet Environ Gen Theory, ISSN 1089-5639, Vol. 110, no 22, p. 7045-56Article in journal (Refereed)
  • 4.
    Dong, XC
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Salhi-Benachenhou, Nessima
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    A theoretical study of the cationic dimerization and polymerization of isobutene1997In: Journal of Molecular Structure: THEOCHEM, ISSN 0166-1280, Vol. 392, p. 111-124Article in journal (Refereed)
    Abstract [en]

    The initial steps in the radiation-induced polymerization of isobutene have been studied by quantum chemical ab initio and semiempirical calculations. The addition of an isobutene cation to a neutral isobutene molecule to form a dimer radical cation is found to be a strongly exothermic reaction, by 29-32 kcal mol(-1) depending on the computational method. A 17 kcal mol(-1) barrier towards a one-hydrogen-shift isomerization reaction, yielding a 2,5-dimethyl-2-hexene radical cation, is obtained at the PMP2/6-31G(d, p) level, which is significantly higher than the value of 6 kcal mol(-1) obtained before for the corresponding isomerization of the ethene dimer radical cation. The further steps of the polymerization of isobutene are investigated in terms of addition reactions between a neutral isobutene moiety and the addition complex formed in the step before. The positive charge and the radical centres are found to be located in opposite ends of each of the radical cationic intermediate complexes, the positive charge centre being energetically the most favourable site of attachment. The overall reaction is thermodynamically favourable and has a high spatial selectivity. The polymer chain has a high structural symmetry and no cross-linking.

  • 5.
    Henningsson, Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Physical Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics I.
    Stashans, A.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Physical Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics I.
    Sandell, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Physical Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics I.
    Rensmo, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Physical Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics I.
    Södergren, Sven
    Lindström, H.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Physical Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics I.
    Vayssieres, L.
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Physical Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics I.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry. Quantum Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Physical Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics I.
    Siegbahn, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Physical Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics I.
    Proton insertion in polycrystalline WO3 studied with electron spectroscopy and semi-empirical calculations2004In: Advances in Quantum Chemistry, ISSN 0065-3276, E-ISSN 2162-8815, Vol. 47, p. 23-36Article in journal (Refereed)
  • 6.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Olovsson, Ivar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Lunell, Sten
    CATION INFLUENCE ON THE STRUCTURE AND ELECTRON-DENSITY OF WATER IN SOME MEN+.H2O COMPLEXES1984In: THEOR CHIM ACTA, ISSN 0040-5744, Vol. 64, no 4, p. 265-276Article in journal (Refereed)
  • 7.
    Jansson, Carl Magnus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Larsson, Per-Erik
    Salhi-Benachenhou, Nessima
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Bergson, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Theoretical Calculations of Kinetic Isotope Effects for a Series of Aziridines2004In: Fundamental World of Quantum Chemistry: A Tribute to the Memory of Per-Olov Löwdin, Volume 3 / [ed] Brändas, Erkki J. and Kryachko, Eugene S., Dordrecht: Kluwer Academic Publishers , 2004Chapter in book (Refereed)
    Abstract [en]

    The nitrogen inversion in aziridine and som parent substituted aziridines is investigated using various computational methods. The stationary points on each potential energy surface are optimized using the B3LYP functional of density functional theory (DFT) in conjuction with the popular 6-31G(d) basis set. Rate constants and thereby kinetic isotope effects (KIEs) are computed at different temperatures using transiton state theory (TST) and various techniques of variational transition state theory (VTST). Moreover, corrections are made for tunneling and non-classical reflection, using three semiclassic correction methods: the Wigner tunneling correction as well as the zero-curvature and the samll-curvature corrections. The performance of the various methods to compute KIEs are compared and the effects of tunneling are discussed.

  • 8. Komaguchi, Kenji
    et al.
    Nomura, K.
    Shiotani, Masaru
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Lund, Anders
    Jansson, Magnus
    Physics, Department of Quantum Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry. Kvantkemi.
    Lunell, Sten
    Physics, Department of Quantum Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry. Quantum Chemistry.
    ESR and theoretical studies of trimer radical cations of coronene2006In: Spectrochimica Acta A, Vol. 63, p. 76-Article in journal (Refereed)
  • 9. Komaguchi, Kenji
    et al.
    Norberg, Daniel
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry. Kvantkemi.
    Nakazawa, Naoko
    Shiotani, Masaru
    Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Persson, Petter
    Department of Physical Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Avdelningen för kvantkemi.
    Lunell, Sten
    Department of Physical Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Avdelningen för kvantkemi.
    Direct ESR evidence for SH2 type reaction of methyl radical with methylsilane and methylgermane in a low temperature solid: A deuterium labeling study2005In: Chemical Physics Letters, Vol. 410, no 1-3, p. 1-5Article in journal (Refereed)
  • 10.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Carlsson, Jan-Otto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    An Ab Initio Study of the Nucleation of Diamond on the Edges of the Graphitic (111) Plane1994In: Journal of Physical Chemistry, p. 5019-Article in journal (Refereed)
  • 11.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Carlsson, Jan-Otto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    Nearest-Neighbour Influence on Hydrocarbon Adsorption on Diamond (111): Studied by Ab Initio Calculations1995In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, p. 10003-Article in journal (Refereed)
  • 12.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    Adsorption of Halogen-Containing Methane on Diamond1998In: Diamond and related materials, ISSN 0925-9635, E-ISSN 1879-0062, p. 1138-Article in journal (Refereed)
  • 13.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    Stability of Hydrogen Terminated Diamond (111) Surfaces1997In: Journal of Physical Chemistry, p. 76-Article in journal (Refereed)
  • 14.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    Carlsson, Jan-Otto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Ab Initio Study of Hydrocarbons on Diamond (111)1993In: Diamond and related materials, ISSN 0925-9635, E-ISSN 1879-0062, Vol. 2, p. 949-Article in journal (Refereed)
  • 15.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    Carlsson, Jan-Otto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Adsorption of hydrocarbons on a Diamond (111) Surface: An Ab Initio Quantum Mechanical Study1993In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, no 4, p. 2666-Article in journal (Refereed)
  • 16.
    Larsson, Per-Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Salhi-Benachenhou, Nessima
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Dong, Xicheng
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Quadricyclane Radical Cation Isomerization Reactions: A Theoretical Study2002In: International Journal of Quantum Chemistry, Vol. 90, p. 1388-1395Article in journal (Refereed)
  • 17.
    Larsson, Per-Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Salhi-Benachenhou, Nessima
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Bicyclo[2.2.1]hepta-2-ene-5-yl-7-ylium Radical Cation: A Theoretical Validation of a Bishomoaromatic Radical Cation Intermediate2003In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 5, no 8, p. 1329-1331Article in journal (Refereed)
    Abstract [en]

    [structure: see text] A natural bond orbital analysis of the distonic bicyclo[2.2.1]hepta-2-ene-5-yl-7-ylium radical cation interprets its structure and radical character by a three-center two-electron bond between C2, C3, and C7 (a bishomoaromatic stabilization) and a singly occupied orbital on C5, n(5). Moreover, B3LYP/6-311+G(d,p) ESR parameters, which agree excellently with experiment, are interpreted in terms of spin polarization in the natural hybrids of sigma(C5-H5), and a dual hyperconjugative effect involving n(5), sigma(C1-H1a), sigma(C1-H1b), and antibonding counterparts.

  • 18.
    Larsson, Per-Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Salhi-Benachenhou, Nessima
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Quadricyclane Radical Cation Rearrangements: A Computational Study of the Transformations to 1,3,5-Cycloheptatriene and Norbornadiene2004In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 10, no 3, p. 681-688Article in journal (Refereed)
    Abstract [en]

    An alternative skeletal rearrangement of the quadricyclane radical cation (Q.+) explains the side products formed in the one-electron oxidation to norbornadiene. First, the bicyclo[2.2.1]hepta-2-ene-5-yl-7-ylium radical cation, with an activation energy of 14.9 kcal mol-1, is formed. Second, this species can further rearrange to 1,3,5-cycloheptatriene through two plausible paths, that is, a multistep mechanism with two shallow intermediates and a stepwise path in which the bicyclo[3.2.0]hepta-2,6-diene radical cation is an intermediate. The multistep rearrangement has a rate-limiting step with an estimated activation energy of 16.5 kcal mol-1, which is 2.8 kcal mol-1 lower in energy than the stepwise mechanism. However, the lowest activation energy is found for the Q.+ cycloreversion to norbornadiene that has a transition structure, in close correspondence with earlier studies, and an activation energy of 10.1 kcal mol-1, which agrees well with the experimental estimate of 9.3 kcal mol-1. The computational estimates of activation energies were done using the CCSD(T)/6-311+G(d,p) method with geometries optimized on the B3LYP/6-311+G(d,p) level, combined with B3LYP/6-311+G(d,p) frequencies.

  • 19.
    Liu, Ya-Jun
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical Chemistry. Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Lund, Anders
    Persson, Petter
    Chemistry, Department of Physical Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Department of Physical and Analytical Chemistry, Quantum Chemistry. Avdelningen för kvantkemi.
    Lunell, Sten
    Chemistry, Department of Physical Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Department of Physical and Analytical Chemistry, Quantum Chemistry. Avdelningen för kvantkemi.
    Density functional theory study of NO adsorbed in A-zeolite2005In: Journal of Physical Chemistry B, Vol. 109, no 16, p. 7948-7951Article in journal (Refereed)
  • 20.
    Liu, Ya-Jun
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical Chemistry. Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Lunell, Sten
    Chemistry, Department of Physical Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Department of Physical and Analytical Chemistry, Quantum Chemistry. Avdelningen för kvantkemi.
    Multireference calculations of the fluorescence, phosphorescence and photodissociation of p-chlorotoluene2005In: Physical Chemistry Chemical Physics, Vol. 7, no 23, p. 3938-3942Article in journal (Refereed)
    Abstract [en]

    Equil. geometries and vibrational frequencies of the ground and some excited states of p-chlorotoluene were calcd. by the complete active space SCF (CASSCF) method. Multi-ref. CASSCF second order perturbation theory (MSCASPT2) calcns. were performed on the vertical excitation energies of six singlet and triplet excited states. The potential energy curves along the Cl-C6H4CH3 bond distance of a no. of low-lying singlet and triplet excited states were calcd. by the CASPT2 method based on CASSCF partially optimized geometries. The fluorescence and one component of the dual phosphorescence obsd. exptl. were clearly explained by the CASPT2 calcd. transition energies. According to those CASPT2 potential energy curves, the photodissocn. of p-chlorotoluene at 266 nm was attributed to the predissocn. of the first triplet excited state after its intersystem crossing with the first singlet excited state. The internal rotation and substitution effects of Me on the photodissocn. were discussed in detail.

  • 21.
    Liu, Ya-Jun
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Persson, Petter
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Lunell, Sten
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Multireference Calculations of the Phosphorescence and Photodissociation of Chlorobenzene2004In: Journal of Chemical Physics, Vol. 121, no 11000Article in journal (Refereed)
    Abstract [en]

    Multireference complete active space self-consistent-field (CASSCF) and multireference CASSF second-order perturbation theory (MSCASPT2) calculations were performed on the ground state and a number of low-lying excited singlet and triplet states of chlorobenzene. The dual phosphorescence observed experimentally is clearly explained by the MSCASPT2 potential-energy curves. Experimental findings regarding the dissociation channels of chlorobenzene at 193, 248, and 266 nm are clarified from extensive theoretical information including all low-energy potential-energy curves.

  • 22.
    Liu, Ya-Jun
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Persson, Petter
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Lunell, Sten
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Theoretical Study of the Fast Photodissociation Channels of the Monohalobenzenes2004In: Journal of Physical Chemistry A, Vol. 108, no 2339Article in journal (Refereed)
    Abstract [en]

    Excited state properties of fluorobenzene, chlorobenzene, bromobenzene, and iodobenzene have been investigated theoretically using multireference CASSCF and CASPT2 methods. Experimentally, chlorobenzene and bromobenzene are known to exhibit one fast dissociation channel, whereas iodobenzene exhibits two fast dissociation channels. The calculations indicate that the chlorobenzene, the bromobenzene, and the slower iodobenzene dissociation channels are due to intersystem crossings from a bound (,*) singlet excited state to a repulsive (n,*) triplet excited state. The faster iodobenzene dissociation channel is instead found to be caused by a direct dissociation of an antibonding (n,*) singlet excited state. The CASPT2 calculations predict that the onset of fluorobenzene photodissociation should occur around 196 nm, with a single time constant longer than 1 ns. CASSCF geometries and accurate MSCASPT2 calculated vertical excitation energies are presented for the ground state as well as the first excited singlet and triplet states of all the monohalobenzenes.

  • 23.
    Liu, Ya-Jun
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Persson, Petter
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Lunell, Sten
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Theoretical Study of the Photodissociation of Low Lying Excited States of Hydrogen Peroxide2004In: Molecular Physics, Vol. 102, no 2575Article in journal (Refereed)
    Abstract [en]

    In order to explain recent photofragmentation experiments of hydrogen peroxide, the vertical excitation energies, potential-energy curves and surfaces, harmonic vibrational frequencies, and transition moments for a number of low lying excited states were calculated. The accessibility of different photodissociation channels for different excitation wavelengths was discussed, on the basis of the calculated results.

  • 24.
    Lundqvist, Maria J.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Nilsing, Mattias
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Åkermark, Björn
    Persson, Petter
    Spacer and anchor effects on the electronic coupling in Ruthenium-bis-terpyridine dye-sensitized TiO2 nanocrystals studied by DFT2006In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 110, no 41, p. 20513-20525Article in journal (Refereed)
    Abstract [en]

    Structural and electronic properties of TiO2 nanoparticles sensitized with a set of Ru(II)(tpy)2 based dyes have been investigated using density functional theory (DFT) calculations combined with time-dependent (TD) DFT calculations. The effects of carboxylic and phosphonic acid anchor groups, as well as a phenylene spacer group, on the optical properties of the dyes and the electronic interactions in the dye-sensitized TiO2 nanoparticles have been investigated. Inclusion of explicit counterions in the modeling shows that the description of the environment is important in order to obtain a realistic interfacial energy level alignment. A comparison of calculated electronic coupling strengths suggests that both the nature of the anchor group and the inclusion of the phenylene spacer group are capable of significantly influencing electron-transfer rates across the dye-metal oxide interface.

  • 25.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Kvantkemi: kemi utan provrör2009In: Annales Academiae regiae scientiarum Upsaliensis: ungl. Vetenskapssamhällets i Uppsala årsbok.Vol 37, 2007-2008, Stockholm: Kungl. Vetenskapssamhället i Uppsala , 2009, p. 111-115Chapter in book (Other academic)
  • 26.
    Lunell, Sten
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Kvantmekanik - filosofi eller ingenjörskonst?2001In: Acta Academiæ Regiæ Scientiaum Upsaliensis, 2001, p. 295-299Chapter in book (Other scientific)
  • 27.
    Lunell, Sten
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Lund, Anders
    Fourteenth International Conference on Radical Ions, Uppsala, Sweden, July 1-5, 1996 .1. Foreword1997Other (Other scientific)
  • 28.
    Nilsing, Mattias
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical Chemistry. Department of Physical and Analytical Chemistry, Quantum Chemistry. Avdelningen för kvantkemi.
    Lunell, Sten
    Chemistry, Department of Physical Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Department of Physical and Analytical Chemistry, Quantum Chemistry. Avdelningen för kvantkemi.
    Persson, Petter
    Chemistry, Department of Physical Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Department of Physical and Analytical Chemistry, Quantum Chemistry. Avdelningen för kvantkemi.
    Ojamäe, Lars
    Chemistry, Department of Physical Chemistry. Department of Physical and Analytical Chemistry, Quantum Chemistry. Avdelningen för kvantkemi.
    Phosphonic acid adsorption at the TiO2 anatase (101) surface investigated by periodic hybrid HF-DFT computations2005In: Surface Science, Vol. 582, no 1-3, p. 49-60Article in journal (Refereed)
  • 29.
    Norberg, Daniel
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Larsson, Per-Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Dong, Xi-Cheng
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Salhi-Benachenhou, Nessima
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Bicyclopropylidene radical cation: A rehybridization ring opening to tetramethyleneethane2004In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 98, no 5, p. 473-483Article in journal (Refereed)
    Abstract [en]

    A computational study has been undertaken to elucidate the mechanism of the bicyclopropylidene radical cation (BCP•+) rearrangement into the tetramethyleneethane radical cation (TME•+). A stepwise mechanism is found for the first ring opening, with an activation energy of 7.3 kcal mol−1, while the second ring opening proceeds with no activation energy. Each ring opening is combined with a striking pyramidalization of one carbon atom in the central bond. In a natural bond orbital (NBO) analysis, the dominating reaction coordinate during the ring opening is found to be the olefinic carbon atom rehybridization, which also favors the continued bond breaking. Widely different ESR parameters are computed for the two sets of four protons in BCP•+, in excellent agreement with the observed spectrum, which are interpreted in the NBO analysis in terms of two hyperconjugative effects. Two minimum energy structures are located for TME•+, separated by a cusp on the internal rotation path of this cation, both of which show ESR parameters in good agreement with the observed spectrum for TME•+.

  • 30.
    Norberg, Daniel
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Quantum Chemistry.
    Shiotani, Masaru
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Quantum Chemistry.
    SH2 reaction vs. hydrogen abstraction/expulsion in methyl radical-methylsilane reactions: Effects of prereactive complex formation2008In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 112, no 6, p. 1330-1338Article in journal (Refereed)
    Abstract [en]

    A quantum chemical study has been undertaken to elucidate the cause of the recently observed S(H)2 reaction between the deuterated methyl radical ((CD3)-C-center dot) and methylsilane (SiD3CH3) following the photolysis of CD3I. [Komaguchi, K.; Norberg, D.; Nakazawa, N.; Shiotani, M.; Persson, P.; Lunell, S. Chem. Phys. Lett. 2005, 410, 1-5.] It is found that the backside SH2 mechanism may proceed favorably for C-Si-C angles deviating with up to 40 degrees from linearity. The competitive hydrogen abstraction reaction is predicted to be active in the range of 90 degrees <= C-Si-C <= 135 degrees. For steeper attack angles, the frontside S(H)2 mechanism is activated. However, high barriers along the corresponding reaction paths probably make the frontside mechanism less important for the present S(H)2 reaction. A number of bound SiH3CH3/CH3I complexes have been located with the MP2 method. At the CCSD(T) level, a complex corresponding to the collinear arrangement where the methyl moiety of methyl iodide points toward the silicon, which is the most favorable conformation for the subsequent S(H)2 reaction with the backside mechanism, is found to be the most stable linear conformer. A complex with similar energy is found where the methyl moiety of methyl iodide points approximately toward an Si-H bond. However, because C-Si-C = 69.4 degrees in this complex, subsequent photolysis of methyl iodide would probably not lead to hydrogen abstraction with full efficiency. These findings could provide an explanation for the observed S(H)2 reaction.

  • 31.
    Persson, Petter
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. QUANTUM CHEMISTRY.
    Gebhart, J. Christof M.
    Lunell, Sten
    Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    The Smallest Possible Nanocrystals of Semiionic Oxides2003In: Journal of Physical Chemistry B, Vol. 107, p. 3336-3339Article in journal (Refereed)
  • 32.
    Persson, Petter
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Stashans, Arvids
    Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Bergström, Robert
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Lunell, Sten
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Periodic INDO calculations of organic adsorbates on a TiO2 surface1998In: Int. J. Quant. Chem., Vol. 70, p. 1055-1066Article in journal (Refereed)
  • 33.
    Salhi-Benachenhou, Nessima
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Alvarez Idaboy, JR
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Model calculations of matrix effects on the conversion of propene radical cations into allyl radicals in halocarbon matrices1997In: Acta Chemica Scandinavica, ISSN 0904-213X, E-ISSN 1902-3103, Vol. 51, no 2, p. 242-248Article in journal (Refereed)
    Abstract [en]

    A comparative study has been undertaken of the conversion of propene radical cations into allyl radicals in the gas phase and in CCl4 and CF4 matrices, The semiempirical UHF/PM3 method, complemented with ab initio PMP2/3-21G and PMP2/6-31G(d, p) calculations, is employed to model this process, which is observed to occur through an ion-molecule reaction by a proton transfer from the propene radical cation to a neutral propene molecule. Single molecules of CCl4 and CF4 are used to model the influence of the corresponding matrices, following two different pathways depending on which proton is transferred. It is found that the reaction in the gas phase occurs without activation energy. In contrast, a barrier is found on the potential energy curve of the reaction in the CCl4 matrix. The strongest interactions are found for CCl4, resulting in a 6.9 kcal mol(-1) activation energy (2.6 kcal mol(-1) for the second pathway). The reaction in CF4 has an intermediate profile with an activation energy of only 2.0 kcal mol(-1) (no barrier for the second pathway). The interactions between the migrating proton and the matrix molecule are interpreted in terms of the basicity of the matrix.

  • 34.
    Salhi-Benachenhou, Nessima
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Alvarez Idaboy, JR
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Eriksson, LA
    Formation of 2-hexene by cationic dimerization of propene: an ab initio and density functional theory study1997In: Theoretical Chemistry accounts, ISSN 1432-881X, E-ISSN 1432-2234, Vol. 97, no 1-4, p. 277-282Article in journal (Refereed)
    Abstract [en]

    The formation of a 2-hexene radical cation from a propene radical cation and a neutral propene molecule is investigated by means of ab initio UHF and spin projected MP2 calculations, as well as the SVWN and B3LYP levels of density functional theory. A stable addition complex, with loose CC bonds, is found. To proceed from the addition complex to the product. a locally planar transition state must be passed, with a migrating hydrogen located half-way between the donating and the accepting carbon atoms. At the highest computational levels considered, PMP2/6-31G(d,p)//MP2/3-21G and B3LYP/6-31G(d,p), this transition state lies approximately 11 and 13 kcal/mol, respectively above the addition complex. The high barrier is believed to be one reason why radical cation oligomerization of propene has not been detected experimentally, in contrast to the case of ethene, where the corresponding barrier is only a few kcal/mol.

  • 35.
    Salhi-Benachenhou, Nessima
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Engels, B
    Huang, M B
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Theoretical study of the ethylene radical cation: geometry and hyperfine structure1998In: Chemical Physics, ISSN 0301-0104, E-ISSN 1873-4421, Vol. 236, no 1-3, p. 53-61Article in journal (Refereed)
    Abstract [en]

    The geometry and the hyperfine structure in the ethylene radical cation have been studied by means of a number of high-level post-SCF ab initio methods, including quadratic CI with single and double substitutions and perturbative triple corrections, QCISD(T), coupled cluster with single and double substitutions and perturbative triple corrections, CCSD(T), and individually selected multi-reference CI with B-K correction, (MRD-CI)/B-K. A value of 20.2 degrees has been computed for the torsion angle in this cation with the QCISD(T)/6-311G(d, p) method, which compares favourably with the experimentally reported angle of similar to 25 degrees. The computed potential barrier to inversion through the planar conformation, as obtained at the QCISD(T)/6-311 + + G(2df, p)//QCISD(T)/6-31 1G(d, p) level (1.24 kJ/mol), is smaller than the experimental value of similar to 3 kJ/mol, but an order of magnitude better than in previous work. The hyperfine coupling constants of the protons and of C-13 are calculated by the (MRD-CI)/B-K method with a relatively large basis set, yielding somewhat larger absolute values than the experimental couplings (-4.0 G for the protons and +6.0 G for C-13, as compared with -2.4 and +4.0 G, respectively). For both the geometrical parameters and the hyperfine couplings, the results of the present study are in considerably better agreement with experiment than previously reported theoretical results.

  • 36.
    Salhi-Benachenhou, Nessima
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Eriksson, Leif A.
    Department of Physics, Stockholm University.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Density functional study of the hexamethyl-(Dewar benzene) radical cation and some related compounds1997In: Acta Chemica Scandinavica, ISSN 0904-213X, E-ISSN 1902-3103, Vol. 51, p. 636-640Article in journal (Refereed)
    Abstract [en]

    A theoretical study has been undertaken of the hexamethyl(Dewar benzene) radical cation (both 2B2 and 2A1 states in C2v symmetry) as well as of two related ions, the pentamethylbenzene and the pentamethylbenzyl trifluoroacetate radical cations, which have been suggested as alternative assignments of the EPR spectrum attributed to the hexamethyl(Dewar benzene) cation. The geometries were optimized at the HF and LDA levels of theory using a standard 6-31G basis set. Single point calculations of the hyperfine coupling constants (hfcc) were then performed at the more accurate MP2, B3PW91, B3LYP and PWP86 levels using larger basis sets. The theoretical results of the present study support the assignment of 2B2 as the ground state of the hexamethyl(Dewar benzene) cation, yielding hydrogen atom hfcc’s in very good agreement with experiment.

  • 37.
    Schnadt, Joachim
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V.
    Brühwiler, Paul A.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V.
    Patthey, Luc
    O'Shea, James N.
    Södergren, Sven
    Department of Physical Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V.
    Odelius, Michael
    Persson, Petter
    Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V.
    Siegbahn, Hans
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V. Fysik I.
    Lunell, Sten
    Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V.
    Mårtensson, Nils
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V.
    Experimental evidence for sub-3-fs charge transfer from an aromatic adsorbate to a semiconductor2002In: Nature, ISSN 0028-0836, Vol. 418, no 6898, p. 620-623Article in journal (Refereed)
    Abstract [en]

    The ultrafast timescale of electron transfer processes is crucial to their role in many biological systems and technological devices. In dye-sensitized solar cells(1-4), the electron transfer from photoexcited dye molecules to nanostructured semiconductor

  • 38.
    Shiotani, Masaru
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Lund, Anders
    Linköpings universitet.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Williams, Ffrancon
    Department of Chemistry, University of Tennessee.
    Structures of the hexafluorocyclopropane, octafluorocyclobutane, and decafluorocyclopentane radical anions probed by experimental and computational studies of anisotropic electron spin resonance (ESR) spectra2007In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 111, no 2, p. 321-338Article in journal (Refereed)
    Abstract [en]

    Anisotropic electron spin resonance (ESR) spectra are reported for the radical anions of hexafluorocyclopropane (c-C3F6-), octafluorocyclobutane (c-C4F8-), and decafluorocyclopentane (c-C5F10-) generated via gamma-irradiation in plastically crystalline tetramethylsilane (TMS) and rigid 2-methyltetrahydrofuran (MTHF) matrices. By combining the analysis of these experimental ESR spectra involving anisotropic hyperfine (hf) couplings with a series of quantum chemical computations, the geometrical and electronic structure of these unusual perfluorocycloalkane radical anions have been characterized more fully than in previous studies that considered only the isotropic couplings. Unrestricted Hartree-Fock (UHF) computations with the 6-311+G(d,p) basis set predict planar ring structures for all three radical anions, the ground electronic states being (2)A(2)" for c-C3F6- (D-3h symmetry), (2)A(2u) for c-C4F8- (D-4h), and (2)A(2)" for c-C5F10- (D-5h), in which the respective six, eight, and ten F-19-atoms are equivalent by symmetry. A successful test of the theoretical computation is indicated by the fact that the isotropic F-19 hf couplings computed by the B3LYP method with the 6-311+G(2df,p) basis set for the optimized geometries are in almost perfect agreement with the experimental values: viz., 19.8 mT (exp) vs 19.78 mT (calc) for c-C3F6-; 14.85 mT (exp) vs 14.84 mT (calc) for c-C4F8-; 11.6 mT (exp) vs 11.65 mT (calc) for c-C5F10-. Consequently, the same computation method has been applied to calculate the almost axially symmetric anisotropic F-19 hf couplings for the magnetically equivalent F-19 atoms: (-4.90 mT, -4.84 mT, 9.75 mT) for c-C3F6-, (-3.54 mT, -3.48 mT, 7.02 mT) for c-C4F8-, and (-2.62 mT, -2.56 mT, 5.18 mT) for c-C5F10-. ESR spectral simulations performed using the computed principal values of the hf couplings and the spatial orientations of the F-19 nuclei as input parameters reveal an excellent fit to the experimental anisotropic ESR spectra of c-C3F6-, c-C4F8-, and c-C5F10-, thereby providing a convincing proof of the highly symmetric D-nh structures that are predicted for these negative ions. Furthermore, using the computed F-19 principal values and their orientations, the effective F-19 anisotropic hf couplings along the molecular symmetry axes were evaluated for c-C3F6- and c-C4F8- and successfully correlated with the positions of the characteristic outermost features in both the experimental and calculated anisotropic spectra. In addition, the electronic excitation energies and oscillator strengths for the c-C3F6-, c-C4F8-, and c-C5F10- radical anions were computed for the first time using time-dependent density functional theory (TD-DFT) methods.

  • 39.
    Shiotani, Masaru
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Persson, Petter
    Physics, Department of Quantum Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry. Quantum Chemistry.
    Lunell, Sten
    Physics, Department of Quantum Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry. Quantum Chemistry.
    Lund, Anders
    Williams, Ffrancon
    Structures of Tetrafluorocyclopropene, Hexafluorocyclobutene, Octafluorocyclopentene and Related Perfluoroalkene Radical Anions Revealed by ESR Spectroscopic and Computational Studies2006In: Journal of Physical Chemistry A, Vol. 110, p. 6307-Article in journal (Refereed)
  • 40. Toriyama, Kazumi
    et al.
    Okazaki, Masaharu
    Jansson, Magnus
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Lund, Anders
    Lunell, Sten
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Isotope effect on the J-T distortion of partially deuteriated benzene cation radicals: an experimental EPR and theoretical DFT study2004In: Physical Chemistry and Chemical Physics: PCCP, Vol. 6, no 1658Article in journal (Refereed)
  • 41.
    Westermark, Karin
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V. Fysik I.
    Rensmo, Håkan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V. Fysik I.
    Schnadt, Joachim
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V.
    Persson, P
    Södergren, S
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V. Fysik I.
    Brühwiler, Paul
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V.
    Lunell, Sten
    Department of Quantum Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V. Kvantkemi.
    Siegbahn, Hans
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Department of Physics and Materials Science, Physics I. Physics V. Fysik I.
    Electron dynamics within Ru-2,2'-bipyridine complexes - an N1s core level excitation study2002In: Chem.Phys., Vol. 285, p. 167-Article in journal (Refereed)
1 - 41 of 41
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