Substitution effects in the 15 N NMR chemical shifts of heterocyclic azines evaluated at the GIAO-DFT level
Copyright © 2018 John Wiley & Sons, Ltd.
| Veröffentlicht in: | Magnetic resonance in chemistry : MRC. - 1985. - 56(2018), 8 vom: 07. Aug., Seite 767-774 |
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| Weitere Verfasser: | , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2018
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| Zugriff auf das übergeordnete Werk: | Magnetic resonance in chemistry : MRC |
| Schlagworte: | Journal Article 15N NMR DFT functionals GIAO-DFT basis sets heterocyclic azines locally dense basis set scheme substitution effects |
| Zusammenfassung: | Copyright © 2018 John Wiley & Sons, Ltd. A systematic study of the accuracy factors for the computation of 15 N NMR chemical shifts in comparison with available experiment in the series of 72 diverse heterocyclic azines substituted with a classical series of substituents (CH3 , F, Cl, Br, NH2 , OCH3 , SCH3 , COCH3 , CONH2 , COOH, and CN) providing marked electronic σ- and π-electronic effects and strongly affecting 15 N NMR chemical shifts is performed. The best computational scheme for heterocyclic azines at the DFT level was found to be KT3/pcS-3//pc-2 (IEF-PCM). A vast amount of unknown 15 N NMR chemical shifts was predicted using the best computational protocol for substituted heterocyclic azines, especially for trizine, tetrazine, and pentazine where experimental 15 N NMR chemical shifts are almost totally unknown throughout the series. It was found that substitution effects in the classical series of substituents providing typical σ- and π-electronic effects followed the expected trends, as derived from the correlations of experimental and calculated 15 N NMR chemical shifts with Swain-Lupton's F and R constants |
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| Beschreibung: | Date Revised 20.11.2019 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1097-458X |
| DOI: | 10.1002/mrc.4731 |