Exchange of amide protons with deuterium results in changes of 13 C chemical shifts for carbon atoms near the site of substitution (CH{N and N{C|O). There is a measurable decrease in the isotopic shifts of CH{N for cycloalkylacetamides as ring size increases from 3 to 8 and for lactams as ring size
Correlation between deuterium isotope effects and 13C-NMR chemical shifts in substituted benzenes
β Scribed by Stefan Berger; Bernd W.K. Diehl
- Publisher
- Elsevier Science
- Year
- 1987
- Tongue
- French
- Weight
- 203 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0040-4039
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β¦ Synopsis
The 1A 13C-NMR isotope shifts induced by deuterium in mono-substituted benzenes are shown to correlate with the chemical shifts of C-l; the sign of the correlation is opposite as previously reported.
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The 100.6MHz =C off-resonance-decoupled and polarization-lransfer NMR spectra of 7,12dimethylbenz[a]anthracene and its 5-deuteriated analogue in deuteriated chloroform solution enabled assignments of the shifts of C-3 and C-5 to be revised, and other spectral ambiguities to be reduced. Negative, i.e
## Abstract The OH chemical shift of the enol form of nitromalonamide is found at 18.9 ppm both in DMSOβ__d__~6~ and in DMFβ__d__~7~ indicating a very strong hydrogen bond. The OH chemical shift is insensitive to temperature changes. Contrary to the large OH chemical shift, a small twoβbond deuteri