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

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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...

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Autores principales: Facelli, J.C., Giribet, C.G., Contreras, R.H.
Formato: JOUR
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00304921_v19_n3_p138_Facelli
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_00304921_v19_n3_p138_Facelli2023-10-03T14:40:36Z 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 Facelli, J.C. Giribet, C.G. Contreras, R.H. 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. Fil:Facelli, J.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Giribet, C.G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Contreras, R.H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00304921_v19_n3_p138_Facelli
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description 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.
format JOUR
author Facelli, J.C.
Giribet, C.G.
Contreras, R.H.
spellingShingle 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
author_facet Facelli, J.C.
Giribet, C.G.
Contreras, R.H.
author_sort Facelli, J.C.
title 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
title_short 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
title_full 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
title_fullStr 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
title_full_unstemmed 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
title_sort 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
url http://hdl.handle.net/20.500.12110/paper_00304921_v19_n3_p138_Facelli
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