NMR spectral assignment of substituted salicylaldoximes by inverse pulse techniques with z-gradient selection: correlation of NMR parameters with substituent constants
✍ Scribed by Erkki Kolehmainen; Ryszard Gawinecki; Borys Ośmiałowski; Katarzyna Trzebiatowska
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 289 KB
- Volume
- 35
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
1H and 13C and also 1H,13C HMQC and 1H,X HMBC (X = 13C and 15N) correlation maps with z-gradient selection of seven salicylaldoximes were recorded and assigned and their parameters are discussed. The chemical shifts of H2, NOH, C7 and especially those of 15NOH correlate well with the Hammett and/or Brown-Okamoto substituent constants. Also the coupling constants 1J(C3,H3) and 1J(C7,H7) are linearly dependent on r'. High correlation coefficients show the presence of the 2-OH group to force the molecules of salicylaldoximes to be planar or almost planar as a result of the intramolecular hydrogen bonding between its hydrogen and oximine nitrogen atom.