Navegar

Colección

Datos Estadísticas

Artículo

Estamos trabajando para incorporar este artículo al repositorio
Consulte el artículo en la página del editor
Consulte la política de Acceso Abierto del editor

Abstract:

Transmission mechanisms of long‐range FH couplings in several fluorinated derivatives of toluene are analysed carrying out partially restricted molecular orbital calculations at the INDO level of approximation. All π‐components follow the A+B sin2θ dependence, with the dihedral angle defined by the exocyclic CH (or CF) bond and the aromatic ring plane. Four‐ and five‐bond couplings show an important σ‐component, which follows the known zig‐zag rule. Both σ‐ and π‐contributions show a conspicuous insensitivity to fluorine ring substitution. Moreover, four‐bond couplings present an important through‐space component, which is negative for a cis arrangement. A sign inversion is found at a dihedral angle between 70° and 80°, which is interpreted as indicating that several through‐space mechanisms are operating. Copyright © 1982 Heyden & Son Ltd.

Registro:

Documento: Artículo
Título:The use of partially restricted molecular orbitals to investigate transmission mechanisms of spin–spin coupling constants. III—an INDO study of long‐range FH couplings in fluorinated derivatives of toluene
Autor:Facelli, J.C.; Giribet, C.G.; Contreras, R.H.
Filiación:Departamento de Física, Facultad de Ciencias Exactas Y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón I, Buenos Aires, 1428, Argentina
Año:1982
Volumen:19
Número:3
Página de inicio:138
Página de fin:143
DOI: http://dx.doi.org/10.1002/mrc.1270190306
Título revista:Organic Magnetic Resonance
Título revista abreviado:Magn. Reson. Chem.
ISSN:00304921
Registro:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00304921_v19_n3_p138_Facelli

Referencias:

  • Contreras, R.H., de Kowalewski, D.G., Osella, A., The effects of substituents on the5J long-range spin-spin coupling constants in substituted benzaldehydes (1979) Organic Magnetic Resonance, 12, p. 542
  • Schaefer, T., Nienczura, W., Wong, C., Marat, K., Spin–spin coupling constants between side-chain and ring fluorine nuclei in some benzotrifluoride, benzal fluoride, and benzyl fluoride derivatives: coupling mechanisms (1979) Canadian Journal of Chemistry, 57, p. 807
  • Wasylishen, R., Schaefer, T., Nuclear Magnetic Resonance Spectra, Conformations, Spin Coupling Mechanisms, and INDO Molecular Orbital Calculations for the Monofluorobenzaldehydes and some Derivatives (1971) Canadian Journal of Chemistry, 49, p. 3216
  • Schaefer, T., Rowbotham, J.B., Proton spin–spin coupling constants and intramolecular hydrogen bonding in bromine derivatives of 1,3-dihydroxybenzene (1976) Canadian Journal of Chemistry, 54, p. 2228
  • de Kowalewski, D.G., Contreras, R.H., Engelmann, A.R., Facelli, J.C., Durán, J.C., Org. Magn. Reson. in Press; Wasylishen, R., Schaefer, T., (1971) Can. J. Chem., 50, p. 1852
  • Schaefer, T., Nienczura, W.P., Sebastian, R., Kruczynski, L.J., Danchura, W., Conformational preferences of the fluoromethyl group inp-methylbenzyl fluoride and some derivatives (1980) Canadian Journal of Chemistry, 58, p. 1178
  • Engelmann, A.R., Contreras, R.H., Facelli, J.C., (1981) Theor. Chim. Acta, 59, p. 17
  • Engelman, A.R., Scuseria, G.E., Contreras, R.H., Paper II of this series, submitted for publication to J. Magn. Reson; Pople, J.A., Beveridge, D.L., (1970) Approximate Molecular Orbital Theory, , McGraw‐Hill, New York
  • Kowalewski, J., (1977) Progress in NMR Spectroscopy, 11, p. 1. , edited by, J. W. Emsley, J. Feeney, L. H. Sutcliffe, Pergamon Press, Oxford
  • Scuseria, G.E., Contreras, R.H., Unrestricted Hartree-Fock instabilities in semiempirical CNDO/S and INDO/S calculations of spin-spin coupling constants (1981) Theoretica Chimica Acta, 59, p. 437
  • Löwdin, P.O., (1969) Adv. Chem. Phys., 14, p. 283
  • Ostlund, N.S., (1972), p. 224. , QCPE IX; Facelli, J.C., Contreras, R.H., Int. J. Quantum Chem. in Press; Pople, J.A., Gordon, M., (1967) J. Am. Chem. Soc., 89, p. 4253
  • Kowalewski, V.J., Contreras, R.H., (1972) J. Magn. Reson., 8, p. 101
  • Barfield, M., Chakrabarti, B., (1969) Chem. Rev., 69, p. 757
  • Wasylishen, R., Schaefer, T., Proton Magnetic Resonance Spectrum of Parafluorotoluene. Sigma and Pi Electron Contributions toJpH,F (1971) Canadian Journal of Chemistry, 49, p. 94
  • Kostelnik, R.J., Williamson, M.P., Wisnowsky, D.E., Castellano, S.M., Nuclear magnetic resonance spectral parameters of α,α,α-trifluorotoluene (1969) Canadian Journal of Chemistry, 47, p. 3313
  • Schaefer, T., Danchura, W., Nienczura, W., Proton magnetic resonance spectra of 3-fluorotoluene and 2-chloro-5-fluorotoluene. The sign and coupling mechanism of (1978) Canadian Journal of Chemistry, 56, p. 2233
  • Schaefer, T., Rowbotham, J.B., Parr, W.J.F., Marat, K., Janzen, A.F., Nuclear magnetic resonance and molecular orbital studies of the conformational preferences of the fluoromethyl group in some benzylfluoride derivatives (1976) Canadian Journal of Chemistry, 54, p. 1322
  • Richards, R.E., Schaefer, T., (1958) Trans. Faraday Soc., 54, p. 1447
  • Rowbotham, J.B., Janzen, A.F., Peeling, J., Schaefer, T., Proton Magnetic Resonance Studies of Rotational Isomerism in Halotoluenes. X. Estimates of Conformational Preferences and Rotational Barriers in Benzal Fluoride and Some Dichloro Derivatives (1974) Canadian Journal of Chemistry, 52, p. 481
  • Hutton, H.M., Rowbotham, J.B., Barber, B.H., Schaefer, T., (1971) Can. J. Chem., 49, p. 2032
  • Hirao, K., Nakatsuji, H., Kato, H., (1973) J. Am. Chem. Soc., 95, p. 31
  • Schaefer, T., Rowbotham, J.B., (1974) Chem. Phys. Lett., 29, p. 633

Citas:

---------- APA ----------
Facelli, J.C., Giribet, C.G. & Contreras, R.H. (1982) . The use of partially restricted molecular orbitals to investigate transmission mechanisms of spin–spin coupling constants. III—an INDO study of long‐range FH couplings in fluorinated derivatives of toluene. Organic Magnetic Resonance, 19(3), 138-143.
http://dx.doi.org/10.1002/mrc.1270190306
---------- CHICAGO ----------
Facelli, J.C., Giribet, C.G., Contreras, R.H. "The use of partially restricted molecular orbitals to investigate transmission mechanisms of spin–spin coupling constants. III—an INDO study of long‐range FH couplings in fluorinated derivatives of toluene" . Organic Magnetic Resonance 19, no. 3 (1982) : 138-143.
http://dx.doi.org/10.1002/mrc.1270190306
---------- MLA ----------
Facelli, J.C., Giribet, C.G., Contreras, R.H. "The use of partially restricted molecular orbitals to investigate transmission mechanisms of spin–spin coupling constants. III—an INDO study of long‐range FH couplings in fluorinated derivatives of toluene" . Organic Magnetic Resonance, vol. 19, no. 3, 1982, pp. 138-143.
http://dx.doi.org/10.1002/mrc.1270190306
---------- VANCOUVER ----------
Facelli, J.C., Giribet, C.G., Contreras, R.H. The use of partially restricted molecular orbitals to investigate transmission mechanisms of spin–spin coupling constants. III—an INDO study of long‐range FH couplings in fluorinated derivatives of toluene. Magn. Reson. Chem. 1982;19(3):138-143.
http://dx.doi.org/10.1002/mrc.1270190306