Experimental and theoretical study of the methoxy group conformational effect on 13C chemical shifts in ortho‐substituted anisoles
Aromatic 13C chemical shifts are reported for a number of ortho‐substituted anisoles. Quantitative determination of the substituent chemical shift (SCS) effects of the methoxy group with a fixed coplanar conformation on aryl carbon nuclei was achieved using experimental and theoretical methods. The...
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1989
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07491581_v27_n2_p158_Biekofsky http://hdl.handle.net/20.500.12110/paper_07491581_v27_n2_p158_Biekofsky |
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paper:paper_07491581_v27_n2_p158_Biekofsky2023-06-08T15:45:28Z Experimental and theoretical study of the methoxy group conformational effect on 13C chemical shifts in ortho‐substituted anisoles Biekofsky, Rodolfo Roberto Pomilio, Alicia Beatriz Facelli, Julio César 13C NMR Methoxy group conformational effect ortho‐Substituted anisoles Substituent chemical shifts Aromatic 13C chemical shifts are reported for a number of ortho‐substituted anisoles. Quantitative determination of the substituent chemical shift (SCS) effects of the methoxy group with a fixed coplanar conformation on aryl carbon nuclei was achieved using experimental and theoretical methods. The experimental values were compared with those calculated through the use of the additivity, and a systematic departure from additivity was found for carbon nuclei in ortho positions. Ortho‐SCSs were found to be non‐equivalent, and the ortho effect on the carbon cis to the fixed methoxy moiety was more shielding than in anisole. The IGLO (Individual Gauge for Localized Orbitals) method was used to calculate the SCSs. Experimental and theoretical trends obtained for the influence of the side‐chain conformations on chemical shifts are in very good agreement with each other, and with recent results obtained by solid‐state NMR. Copyright © 1989 John Wiley & Sons, Ltd. Fil:Biekofsky, R.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Pomilio, A.B. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Facelli, J.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1989 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07491581_v27_n2_p158_Biekofsky http://hdl.handle.net/20.500.12110/paper_07491581_v27_n2_p158_Biekofsky |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
13C NMR Methoxy group conformational effect ortho‐Substituted anisoles Substituent chemical shifts |
| spellingShingle |
13C NMR Methoxy group conformational effect ortho‐Substituted anisoles Substituent chemical shifts Biekofsky, Rodolfo Roberto Pomilio, Alicia Beatriz Facelli, Julio César Experimental and theoretical study of the methoxy group conformational effect on 13C chemical shifts in ortho‐substituted anisoles |
| topic_facet |
13C NMR Methoxy group conformational effect ortho‐Substituted anisoles Substituent chemical shifts |
| description |
Aromatic 13C chemical shifts are reported for a number of ortho‐substituted anisoles. Quantitative determination of the substituent chemical shift (SCS) effects of the methoxy group with a fixed coplanar conformation on aryl carbon nuclei was achieved using experimental and theoretical methods. The experimental values were compared with those calculated through the use of the additivity, and a systematic departure from additivity was found for carbon nuclei in ortho positions. Ortho‐SCSs were found to be non‐equivalent, and the ortho effect on the carbon cis to the fixed methoxy moiety was more shielding than in anisole. The IGLO (Individual Gauge for Localized Orbitals) method was used to calculate the SCSs. Experimental and theoretical trends obtained for the influence of the side‐chain conformations on chemical shifts are in very good agreement with each other, and with recent results obtained by solid‐state NMR. Copyright © 1989 John Wiley & Sons, Ltd. |
| author |
Biekofsky, Rodolfo Roberto Pomilio, Alicia Beatriz Facelli, Julio César |
| author_facet |
Biekofsky, Rodolfo Roberto Pomilio, Alicia Beatriz Facelli, Julio César |
| author_sort |
Biekofsky, Rodolfo Roberto |
| title |
Experimental and theoretical study of the methoxy group conformational effect on 13C chemical shifts in ortho‐substituted anisoles |
| title_short |
Experimental and theoretical study of the methoxy group conformational effect on 13C chemical shifts in ortho‐substituted anisoles |
| title_full |
Experimental and theoretical study of the methoxy group conformational effect on 13C chemical shifts in ortho‐substituted anisoles |
| title_fullStr |
Experimental and theoretical study of the methoxy group conformational effect on 13C chemical shifts in ortho‐substituted anisoles |
| title_full_unstemmed |
Experimental and theoretical study of the methoxy group conformational effect on 13C chemical shifts in ortho‐substituted anisoles |
| title_sort |
experimental and theoretical study of the methoxy group conformational effect on 13c chemical shifts in ortho‐substituted anisoles |
| publishDate |
1989 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07491581_v27_n2_p158_Biekofsky http://hdl.handle.net/20.500.12110/paper_07491581_v27_n2_p158_Biekofsky |
| work_keys_str_mv |
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| _version_ |
1768546633045245952 |