Prediction of vicinal proton-proton coupling constants 3J HH from density functional theory calculations
Vicinal coupling constants 3JHH have been calculated at the optimized geometries for a series of selected molecules with the aim of developing a practical procedure for predicting this kind of coupling. Calculations of couplings and optimizations of molecular geometries have been carried out at the...
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2005
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paper:paper_00268976_v103_n9_p1307_Diez2023-06-08T14:53:59Z Prediction of vicinal proton-proton coupling constants 3J HH from density functional theory calculations Barone, Verónica Peralta, Juan Ernesto Contreras, Rubén Horacio Couplings Data acquisition Ethane Mathematical models Optimization Probability density function Cyclohexanes Karplus equation Molecular geometries Vicinal coupling constants Protons Vicinal coupling constants 3JHH have been calculated at the optimized geometries for a series of selected molecules with the aim of developing a practical procedure for predicting this kind of coupling. Calculations of couplings and optimizations of molecular geometries have been carried out at the DFT/B3LYP level using a moderate sized basis set. When the Fermi contact contributions to 3JHH calculated for 25 mono- and 23 1,1-di-substituted ethanes are multiplied by a factor of 0.904, the corresponding predicted couplings Jpre are in good agreement with the experimental Jexp couplings, with standard deviation σ of 0.10 Hz. When such a comparison is carried out for the remaining sets of molecules the σ deviation increases to 0.26 Hz for a dataset of 21 couplings from 11 monosubstituted cyclohexanes, to 0.19 Hz for a dataset of 40 couplings from 6 norbornane type molecules and to 0.25 Hz for a dataset of 54 couplings from 14 three-membered rings. For the complete dataset of 163 couplings the σ deviation amounts to 0.20 Hz. This figure is further reduced to 0.17 Hz by adding to the Jpre coupling a small correction given by the term -0.15cosφ, depending on the dihedral angle φ between the coupled protons. A larger σ deviation of 0.31 Hz was reported for the best empirically parameterized extended Karplus equation. DFT Jpre values could be further improved by more accurate calculations for the pertinent substituted ethane constituents of the molecule in question by applying a substituent effect model. © 2005 Taylor & Francis Group Ltd. Fil:Barone, V. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Peralta, J.E. 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. 2005 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00268976_v103_n9_p1307_Diez http://hdl.handle.net/20.500.12110/paper_00268976_v103_n9_p1307_Diez |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Couplings Data acquisition Ethane Mathematical models Optimization Probability density function Cyclohexanes Karplus equation Molecular geometries Vicinal coupling constants Protons |
| spellingShingle |
Couplings Data acquisition Ethane Mathematical models Optimization Probability density function Cyclohexanes Karplus equation Molecular geometries Vicinal coupling constants Protons Barone, Verónica Peralta, Juan Ernesto Contreras, Rubén Horacio Prediction of vicinal proton-proton coupling constants 3J HH from density functional theory calculations |
| topic_facet |
Couplings Data acquisition Ethane Mathematical models Optimization Probability density function Cyclohexanes Karplus equation Molecular geometries Vicinal coupling constants Protons |
| description |
Vicinal coupling constants 3JHH have been calculated at the optimized geometries for a series of selected molecules with the aim of developing a practical procedure for predicting this kind of coupling. Calculations of couplings and optimizations of molecular geometries have been carried out at the DFT/B3LYP level using a moderate sized basis set. When the Fermi contact contributions to 3JHH calculated for 25 mono- and 23 1,1-di-substituted ethanes are multiplied by a factor of 0.904, the corresponding predicted couplings Jpre are in good agreement with the experimental Jexp couplings, with standard deviation σ of 0.10 Hz. When such a comparison is carried out for the remaining sets of molecules the σ deviation increases to 0.26 Hz for a dataset of 21 couplings from 11 monosubstituted cyclohexanes, to 0.19 Hz for a dataset of 40 couplings from 6 norbornane type molecules and to 0.25 Hz for a dataset of 54 couplings from 14 three-membered rings. For the complete dataset of 163 couplings the σ deviation amounts to 0.20 Hz. This figure is further reduced to 0.17 Hz by adding to the Jpre coupling a small correction given by the term -0.15cosφ, depending on the dihedral angle φ between the coupled protons. A larger σ deviation of 0.31 Hz was reported for the best empirically parameterized extended Karplus equation. DFT Jpre values could be further improved by more accurate calculations for the pertinent substituted ethane constituents of the molecule in question by applying a substituent effect model. © 2005 Taylor & Francis Group Ltd. |
| author |
Barone, Verónica Peralta, Juan Ernesto Contreras, Rubén Horacio |
| author_facet |
Barone, Verónica Peralta, Juan Ernesto Contreras, Rubén Horacio |
| author_sort |
Barone, Verónica |
| title |
Prediction of vicinal proton-proton coupling constants 3J HH from density functional theory calculations |
| title_short |
Prediction of vicinal proton-proton coupling constants 3J HH from density functional theory calculations |
| title_full |
Prediction of vicinal proton-proton coupling constants 3J HH from density functional theory calculations |
| title_fullStr |
Prediction of vicinal proton-proton coupling constants 3J HH from density functional theory calculations |
| title_full_unstemmed |
Prediction of vicinal proton-proton coupling constants 3J HH from density functional theory calculations |
| title_sort |
prediction of vicinal proton-proton coupling constants 3j hh from density functional theory calculations |
| publishDate |
2005 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00268976_v103_n9_p1307_Diez http://hdl.handle.net/20.500.12110/paper_00268976_v103_n9_p1307_Diez |
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