Additivity scheme in nmr chemical shifts of disubstituted pyridines
An additivity relationship for chemical shifts similar to that found in the literature for coupling constants has been tested in eleven disubstituted pyridines. The chemical shifts of these disubstituted pyridines were measured in different solvents at different concentrations and extrapolated to in...
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00222860_v23_n2_p209_Contreras |
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todo:paper_00222860_v23_n2_p209_Contreras2023-10-03T14:30:36Z Additivity scheme in nmr chemical shifts of disubstituted pyridines Contreras, R.H. de Kowalewski, D.G. An additivity relationship for chemical shifts similar to that found in the literature for coupling constants has been tested in eleven disubstituted pyridines. The chemical shifts of these disubstituted pyridines were measured in different solvents at different concentrations and extrapolated to infinite dilution. In order to compute the "effects" of the different substituents, the chemical shifts of the corresponding monosubstituted pyridines and of pyridine were measured in the same solvents at different concentrations. These chemical shifts were extrapolated to infinite dilution. In most cases it was found that the extrapolated chemical shifts for disubstituted pyridines are in good agreement with those calculated using the additivity relationship. Only in a few cases was it found that the additivity scheme does not hold. © 1974. 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_00222860_v23_n2_p209_Contreras |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
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R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| description |
An additivity relationship for chemical shifts similar to that found in the literature for coupling constants has been tested in eleven disubstituted pyridines. The chemical shifts of these disubstituted pyridines were measured in different solvents at different concentrations and extrapolated to infinite dilution. In order to compute the "effects" of the different substituents, the chemical shifts of the corresponding monosubstituted pyridines and of pyridine were measured in the same solvents at different concentrations. These chemical shifts were extrapolated to infinite dilution. In most cases it was found that the extrapolated chemical shifts for disubstituted pyridines are in good agreement with those calculated using the additivity relationship. Only in a few cases was it found that the additivity scheme does not hold. © 1974. |
| format |
JOUR |
| author |
Contreras, R.H. de Kowalewski, D.G. |
| spellingShingle |
Contreras, R.H. de Kowalewski, D.G. Additivity scheme in nmr chemical shifts of disubstituted pyridines |
| author_facet |
Contreras, R.H. de Kowalewski, D.G. |
| author_sort |
Contreras, R.H. |
| title |
Additivity scheme in nmr chemical shifts of disubstituted pyridines |
| title_short |
Additivity scheme in nmr chemical shifts of disubstituted pyridines |
| title_full |
Additivity scheme in nmr chemical shifts of disubstituted pyridines |
| title_fullStr |
Additivity scheme in nmr chemical shifts of disubstituted pyridines |
| title_full_unstemmed |
Additivity scheme in nmr chemical shifts of disubstituted pyridines |
| title_sort |
additivity scheme in nmr chemical shifts of disubstituted pyridines |
| url |
http://hdl.handle.net/20.500.12110/paper_00222860_v23_n2_p209_Contreras |
| work_keys_str_mv |
AT contrerasrh additivityschemeinnmrchemicalshiftsofdisubstitutedpyridines AT dekowalewskidg additivityschemeinnmrchemicalshiftsofdisubstitutedpyridines |
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1807314584735842304 |