@article{EngelsPeyerimhoff1989,
  author    = {Engels, Bernd and Peyerimhoff, S.D.},
  title     = {Theoretical study of FC\(_2\)H\(_4\)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58824},
  year      = {1989},
  abstract  = {Large-scale multireference configuration interaction (MRD-CI) calculations in a quite flexible AO basis are employed to study the energy hypersurface for the reaction intermediate FC\(_2\)H\(_4\) • The reaction F + C\(_2\)H\(_4\) -> FC\(_2\)H\(_4\) as weil as the 1,2 migration of the fluorine atom in FC\(_2\)H\(_4\) is investigated. In addition the rotation around the CC bond in the optimum conformation is studied. The absolute minimum in the potential energy is found for the asymmetric structure but the symmetric structure is also found to be stable with respect to the dissociation, so that a shuttling of the fluorine atom is in principle possible but highly unlikely because ( l) the activation energy is high ( II 5-130 kJ fmol) and the saddle point lies only 4(}-50 kJ jmol below the dissociation Iimit of F + C\(_2\)H\(_4\) and (2) the competitive motion, i.e., rotation around the CC axis, is nearly free (I 1-17 kJ/mol).},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{KarnaGreinEngelsetal.1989,
  author    = {Karna, S. and Grein, F. and Engels, Bernd and Peyerimhoff, S.D.},
  title     = {The hyperfine coupling constants of \(^{19}\)F\(_2\)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58817},
  year      = {1989},
  abstract  = {The isotropic (a\(_{iso}\)) and dipolar (A\(_{dip}\)) hyperfine coupling constants of 19F2 were obtained from MRD-CI wave functions using a variety of basis sets. In series I, increasing numbers of d functions were added to a 5s4p contracted Huzinaga!Dunning basis. In series II, the 5s3p basis set was uncontracted in several steps until 9s5p was reached, to which were added from one to three d-polarization functions. Cl parameters (selectioo threshoids and the number of reference coofiguratioos) were also varied. A study of the R dependence of aiso and Adip was perfonned. The best values obtained at R\(_e\) are 260 G for a\(_{iso}\) and 308 G for A\(_{dip}\)• compared with experimental values of about 280 G for a;10 and 320 G for A\(_{dip}\)·},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{EngelsPeyerimhoffKarnaetal.1988,
  author    = {Engels, Bernd and Peyerimhoff, S.D. and Karna, S.P. and Grein, F.},
  title     = {The hyperfine coupling constants of the five lowest states of CH : An ab initio MRD-CI study},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58807},
  year      = {1988},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{EngelsPeyerimhoff1988,
  author    = {Engels, Bernd and Peyerimhoff, S.D.},
  title     = {Study of the 1s and 2s shell contributions to the isotropic hyperfine coupling constant in nitrogen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58793},
  year      = {1988},
  abstract  = {The istropic part of the hyperfine coupling constant is investigated by means of multireference configuration interaction calculations employing Gaussian basis sets. A detailed study of the 1s and 2s spin polarisation in the nitrogen atom and the NH molecule shows that the structure of the lower-energy space of the unoccupied orbitals is essential for the results. A contraction of the Gaussian basis is possible without loss of accuracy if enough flexibility is retained to describe the main features of the original space of unoccupied functions. Higher than double excitations are found to be non-negligible for the description of α\(_{iso}\).},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{EngelsPeyerimhoffDavidson1987,
  author    = {Engels, Bernd and Peyerimhoff, S.D. and Davidson, E.R.},
  title     = {Calculation of hyperfine coupling constants : An ab initio MRD-CI study for nitrogen to analyse the effects of the basis sets and CI parameter},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58784},
  year      = {1987},
  abstract  = {The hyperfine coupling constant for the nitrogen atom is evaluated by large-scale MRD-CI calculations. A detailed analysis of the charge density at the nucleus and the spin polarization in the ls and 2s shell as a function of various technical parameters is undertaken. Various (s, p) AO basis sets and the inftuence of correlation orbitals is investigated as weil as selection threshold and other properlies in CI calculations. The best value, obtained for the isotropic hyperfine coupling constant in an s, p, d basis, based on theoretical judgment of' best' quantities, is 9·9 MHz compared to 10·4509 MHz.},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{EngelsPeyerimhoff1986,
  author    = {Engels, Bernd and Peyerimhoff, S. D.},
  title     = {Theoretical study of the bridging in β-Halo Ethyl},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58779},
  year      = {1986},
  abstract  = {Large-acale multi-reference configuration interaction (MRD-CI) calculations in a quite flexible AO basis are employed to study the energy hypersurface for the reaction intermediates XC\(_3\)H\(_4\) with X = Cl, Br and F. Particular emphasis is therby placed on determining the equilibrium conformations, the CH\(_2\) rotation barrier and the energy surface for a possible bridging (shuttling motion (1a] of X between the two carbon centers). The absolute minimum in the potential energy surface is found in all three cases for the asymmetric ß-halo radical in general agreement with ESR data at an XCC angle of ca. 110°, a c-c separation somewhat shorter than a single bond and an approximate sp3 type hybridization (\(\alpha _2 \approx \) 135-140°). In FC\(_2\)H\(_4\) the energy difference between the minimum in the symmetric conformation and the absolute minimum is found to be more than 30 kcal so that shuttling seems impossible in agreement with experimental findings. In BrC\(_2\)H\(_4\) the difference between these two potential minima is only between 1-2 kcal, i.e., smaller than the barrier to CH\(_2\), rotation, so that· shuttling is favored, while ClC\(_2\)H\(_4\) takes an intermediate position between these extremes. The use of correlated wavefunctions is found to be quite important for such a study; the results are related to various kinetic studies of these radicals.},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{BentleyChristlKemmeretal.1994,
  author    = {Bentley, T. W. and Christl, Manfred and Kemmer, R. and Llewellyn, G. and Oakley, J. E.},
  title     = {Kinetic and Spectroscopic Characterisation of Highly Reactive Methanesulfonates. Leaving Group Effects for Solvolyses and Comments on Geminal Electronic Effects Influencing S\(_N\)1 Reactivity},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58748},
  year      = {1994},
  abstract  = {Highly reactive methanesulfonates (mesylates, ROMs) have been prepared from 1-phenylethanol. cyclohex-2-en-1-ol, diphenylmethanol and p-methoxybenzyl alcohol by treatment with methanesulfonyl chloride and triethylamine in dichloro- or trichloro-methane at - 20 to 0 °C. The mesylates. characterised in solution by \(^1\)H and \(^{13}\)C NMR at -20 °C, were obtained in satisfactory purity (ca. 95\%) in cold solutions but they decomposed by reaction with chloride, triethylamine or the parent alcohol. Rate constants for solvolyses in aqueous acetone and aqueous ethanol have been determined by a fast response conductimetric method. Product selectivities for solvolyses of pmethoxybenzyl mesylate in aqueous ethanol and methanol at 0 °C have been determined by HPLC. From additional new or Iiterature kinetic data for solvolyses of corresponding bromides. chlorides and p-nitrobenzoates (OPNB). Br/CI. OMs/Br and OMs/OPNB rate ratios were calculated; the results are consistent with electronic effects stabilising the carbocationic transition states and increasing OMs/Br rate ratios for these SN 1 solvolyses; none of the evidence supports a geminal electronic effect on Br/CI rate ratios (e.g. caused by stabilisation of the initial state in pmethoxybenzyl chloride). Steric effects on ester /halide rate ratios for solvolyses of tertiary substrates are confirmed. Relative rates over a 10\(^{16}\) range for ester and halide leaving groups are evaluated for solvolyses of 1-phenylethyl substrates in 80\% ethanol-water. updating previous work by Noyce et al. (1972).},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{ChristlTuerkPetersetal.1994,
  author    = {Christl, Manfred and T{\"u}rk, M. and Peters, K. and Peters, E.-M. and Schnering, H. G. von},
  title     = {Octahydro-1,2,3:4,5,6-dimethenopentalene-2-carbonitrile, the First Derivative of a Yet-Unknown (CH)\(_{10}\)-Hydrocarbon},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58731},
  year      = {1994},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{ChristlTuerkPetersetal.1994,
  author    = {Christl, Manfred and T{\"u}rk, M. and Peters, K. and Peters, E.-M. and Schnering, H. G. von},
  title     = {Octahydro-1,2,3:4,5,6-dimethenopentalen-2-carbonitril, das erste Derivat eines noch unbekannten (CH)\(_{10}\)-Kohlenwasserstoffs},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58728},
  year      = {1994},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {de}
}
@article{ChristlBraunWolzetal.1994,
  author    = {Christl, Manfred and Braun, Martin and Wolz, E. and Wagner, W.},
  title     = {Cycloallene, 9 - 1-Phenyl-1-aza-3,4-cyclohexadien, das erste Isodihydropyridin: Erzeugung und Abfangreaktionen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58714},
  year      = {1994},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {de}
}
@article{GerstnerKemmerChristl1994,
  author    = {Gerstner, E. and Kemmer, R. and Christl, Manfred},
  title     = {Elektrophile Additionen an das Bicyclo[1.1.0]butan-System von Tricyclo[4.1.0.0\(^{2,7}\)]-heptan-Derivaten: Halogen-Elektrophile},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58700},
  year      = {1994},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {de}
}
@article{ChristlGerstnerKemmeretal.1994,
  author    = {Christl, Manfred and Gerstner, E. and Kemmer, R. and Llewellyn, G. and Bentley, T. W.},
  title     = {Elektrophile Additionen an das Bicyclo[1.1.0]butan-System von 1-Phenyl- und 1-(4-Anisyl)tricyclo[4.1.0.0\(^{2,7}\)]heptan: S{\"a}ure-katalysierte Reaktionen mit Wasser und Methanol, Anlagerung von Essigs{\"a}ure und Oxymercurierung},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58696},
  year      = {1994},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {de}
}
@article{BentleyNormanGerstneretal.1993,
  author    = {Bentley, T. W. and Norman, S. J. and Gerstner, E. and Kemmer, R. and Christl, Manfred},
  title     = {Solvolysis of Tricyclo[3.1.0.0\(^{2,6}\)]hex-3-yl and Bicyclo[2.1.1]hex-2-yl Sulfonates},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58689},
  year      = {1993},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{FeineisSchwarzHegmannetal.1993,
  author    = {Feineis, E. and Schwarz, H. and Hegmann, J. and Christl, Manfred and Peters, K. and Peters, E.-M. and Schnering, H. G. von},
  title     = {Cycloadditionen von 6H-1,3,4-0xadiazin-6-onen (4,5-Diaza-α-pyronen), 13 - Diels-Alder-Reaktionen mit 6H-1,3,4-Oxadiazin-6-onen als Dienophil},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58673},
  year      = {1993},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {de}
}
@article{ChristlLanzendoerferGroetschetal.1993,
  author    = {Christl, Manfred and Lanzend{\"o}rfer, U. and Gr{\"o}tsch, M. M. and Hegmann, J. and Ditterich, E. and H{\"u}ttner, G. and Peters, K. and Peters, E.-M. and Schnering, H. G. von},
  title     = {Cycloadditionen von 6H-1,3,4-0xadiazin-6-onen (4,5-Diaza-α-pyronen), 12 - Dieckmann-Kondensationen ohne Basen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58665},
  year      = {1993},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {de}
}
@article{ChristlMueller1993,
  author    = {Christl, Manfred and M{\"u}ller, H.},
  title     = {Induktiver Effekt, negative Hyperkonjugation und Gegenion sind nicht die Ursache der besonderen Eigenschaften des Bicyclo[3.2.1]octa-3,6-dien-2-yl-Anions. - Eine NMR-Studie mit phenylsubstituierten Modellen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58655},
  year      = {1993},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {de}
}
@article{HegmannDitterichHuettneretal.1992,
  author    = {Hegmann, J. and Ditterich, E. and H{\"u}ttner, G. and Christl, Manfred and Peters, K. and Peters, E.-M. and Schnering, H. G. von},
  title     = {δ-Chlor-δ-lactone aus γ-Oxoketenen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58649},
  year      = {1992},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {de}
}
@article{ChristlBraunMueller1992,
  author    = {Christl, Manfred and Braun, Martin and M{\"u}ller, Germar},
  title     = {1,2,4-Cyclohexatriene, an Isobenzene, and Bicyclo[4.4.0)deca-1,3,5,7,8-pentaene, an Isonaphthalene: Generation and Trapping Reactions},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58639},
  year      = {1992},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {en}
}
@article{ChristlStanglJelinekFink1992,
  author    = {Christl, Manfred and Stangl, R. and Jelinek-Fink, H.},
  title     = {Zur Kenntnis der thermischen Umlagerung des Bicyclo[1.1.0]butan-Systems. Eine kinetische Studie des {\"U}bergangs von Tricyclo[4.1.0.0\(^{2,7}\)]heptanen in Bicyclo[3.2.0]hept-6-ene},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58623},
  year      = {1992},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {de}
}
@article{StanglJelinekFinkChristl1992,
  author    = {Stangl, R. and Jelinek-Fink, H. and Christl, Manfred},
  title     = {Darstellung phenylsubstituierter Derivate des Tricyclo[4.1.0.0\(^{2,7}\)]heptans und des 1,2,3,4-Tetrahydro-1,2,3-methenonaphthalins},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58610},
  year      = {1992},
  abstract  = {No abstract available},
  subject      = {Organische Chemie},
  language  = {de}
}