Ring current and anisotropy effects on OH chemical shifts in resonance-assisted intramolecular H-bonds
- Ring current effects on resonance-assisted and intramolecularly bridged hydrogen bond protons for 10-hydroxybenzo[h]quinoline 1 and a number of related compounds were calculated and the through-space NMR shieldings (TSNMRS) obtained hereby visualized as iso-chemical-shielding surfaces (ICSS) of various size and direction. These calculations revealed that this through-space effect is comparably large (up to 2 ppm) dependent on the position of the intramolecularly bridged OH proton, and therefore, contribute considerably to the chemical shift of the latter making it questionable to use delta(OH)/ppm in the estimation of intramolecular hydrogen bond strength without taking this into account. Furthermore, the anisotropy effects of additional groups on the aromatic moiety (e.g. the carbonyl group in salicylaldehyde or in o-hydroxyacetophenone of ca. 0.6 ppm deshielding) should also be considered. These through-space effects need to be taken into account when using OH chemical shifts to estimate hydrogen bond strength.
Verfasserangaben: | Poul Erik HansenORCiD, Andreas KochORCiDGND, Erich KleinpeterORCiDGND |
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DOI: | https://doi.org/10.1016/j.tetlet.2018.05.006 |
ISSN: | 0040-4039 |
Titel des übergeordneten Werks (Englisch): | Tetrahedron letters |
Verlag: | Elsevier |
Verlagsort: | Oxford |
Publikationstyp: | Wissenschaftlicher Artikel |
Sprache: | Englisch |
Datum der Erstveröffentlichung: | 03.05.2018 |
Erscheinungsjahr: | 2018 |
Datum der Freischaltung: | 19.11.2021 |
Freies Schlagwort / Tag: | Anisotropy effect; Iso-chemical-shielding surfaces (ICSS); RA-intramolecular hydrogen bond; Ring current effect; Through-space NMR shieldings (TSNMRS) |
Band: | 59 |
Ausgabe: | 23 |
Seitenanzahl: | 5 |
Erste Seite: | 2288 |
Letzte Seite: | 2292 |
Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
DDC-Klassifikation: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
Peer Review: | Referiert |