Lone-pair orientation effect of an α-oxygen atom on 1JCC NMR spin-spin coupling constants in o-substituted phenols. Experimental and DFT study
The well-known N lone-pair orientation effect on 1JCC spin-spin coupling constants (SSCCs) in oximes and their derivatives was used to study how negative hyperconjugative interactions of type LP1(O) → σ*CC depend on ortho interactions involving the OH group. This study demanded the following analyse...
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todo:paper_15499618_v3_n4_p1284_Taurian2023-10-03T16:23:19Z Lone-pair orientation effect of an α-oxygen atom on 1JCC NMR spin-spin coupling constants in o-substituted phenols. Experimental and DFT study Taurian, O.E. Contreras, R.H. De Kowalewski, D.G. Pérez, J.E. Tormena, C.F. The well-known N lone-pair orientation effect on 1JCC spin-spin coupling constants (SSCCs) in oximes and their derivatives was used to study how negative hyperconjugative interactions of type LP1(O) → σ*CC depend on ortho interactions involving the OH group. This study demanded the following analyses: (i) a qualitative estimation of how 1JCC SSCCs are affected by hyperconjugative interactions, (ii) a study of similar stereochemical effects to those in oximes, but in 1JCC and 1JC1C6 in a series of 2-substituted phenols, and (iii) a quantitative estimation, with the natural bond order approach, of some key electron derealization interactions. A few unexpected results are quoted. LP1(O) → σ* CC interactions are affected by proximity interactions as follows: (a) they are enhanced by hydrogen bonds transferring charge into the (O-H)* antibonding orbital; (b) they are enhanced by proximity interactions of type LP1(O)⋯H-C; (c) they are inhibited by interactions of type LP(O1)⋯H-O. Consequences of these observations are discussed. © 2007 American Chemical Society. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_15499618_v3_n4_p1284_Taurian |
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Universidad de Buenos Aires |
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I-28 |
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R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| description |
The well-known N lone-pair orientation effect on 1JCC spin-spin coupling constants (SSCCs) in oximes and their derivatives was used to study how negative hyperconjugative interactions of type LP1(O) → σ*CC depend on ortho interactions involving the OH group. This study demanded the following analyses: (i) a qualitative estimation of how 1JCC SSCCs are affected by hyperconjugative interactions, (ii) a study of similar stereochemical effects to those in oximes, but in 1JCC and 1JC1C6 in a series of 2-substituted phenols, and (iii) a quantitative estimation, with the natural bond order approach, of some key electron derealization interactions. A few unexpected results are quoted. LP1(O) → σ* CC interactions are affected by proximity interactions as follows: (a) they are enhanced by hydrogen bonds transferring charge into the (O-H)* antibonding orbital; (b) they are enhanced by proximity interactions of type LP1(O)⋯H-C; (c) they are inhibited by interactions of type LP(O1)⋯H-O. Consequences of these observations are discussed. © 2007 American Chemical Society. |
| format |
JOUR |
| author |
Taurian, O.E. Contreras, R.H. De Kowalewski, D.G. Pérez, J.E. Tormena, C.F. |
| spellingShingle |
Taurian, O.E. Contreras, R.H. De Kowalewski, D.G. Pérez, J.E. Tormena, C.F. Lone-pair orientation effect of an α-oxygen atom on 1JCC NMR spin-spin coupling constants in o-substituted phenols. Experimental and DFT study |
| author_facet |
Taurian, O.E. Contreras, R.H. De Kowalewski, D.G. Pérez, J.E. Tormena, C.F. |
| author_sort |
Taurian, O.E. |
| title |
Lone-pair orientation effect of an α-oxygen atom on 1JCC NMR spin-spin coupling constants in o-substituted phenols. Experimental and DFT study |
| title_short |
Lone-pair orientation effect of an α-oxygen atom on 1JCC NMR spin-spin coupling constants in o-substituted phenols. Experimental and DFT study |
| title_full |
Lone-pair orientation effect of an α-oxygen atom on 1JCC NMR spin-spin coupling constants in o-substituted phenols. Experimental and DFT study |
| title_fullStr |
Lone-pair orientation effect of an α-oxygen atom on 1JCC NMR spin-spin coupling constants in o-substituted phenols. Experimental and DFT study |
| title_full_unstemmed |
Lone-pair orientation effect of an α-oxygen atom on 1JCC NMR spin-spin coupling constants in o-substituted phenols. Experimental and DFT study |
| title_sort |
lone-pair orientation effect of an α-oxygen atom on 1jcc nmr spin-spin coupling constants in o-substituted phenols. experimental and dft study |
| url |
http://hdl.handle.net/20.500.12110/paper_15499618_v3_n4_p1284_Taurian |
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