## Abstract High precision ^14^N nuclear screening data are presented for some alkyl‐ and aryl‐__N__‐sulphinylamines. For the alkyl compounds the β effect is seen to produce a decrease in screening and the opposite influence from the γ effect is also observed. An exception to the general tendency f
14N NMR single-crystal study of hexamethylenetetramine
✍ Scribed by Young-Sik Kye; Gerard S. Harbison
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 161 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0749-1581
No coin nor oath required. For personal study only.
✦ Synopsis
The 14N NMR spectrum of hexamethylenetetramine (HMT) is dominated by the very large electric quadrupole coupling constant of 4.412 MHz at room temperature. Nonetheless, by carefully accounting for this interaction one can subtract its Ðrst-and second-order e †ects on the spectrum, leaving the much smaller anisotropic chemical shift interaction. The chemical shielding anisotropy of HMT is [8.3 ^3.2 ppm, small but di †erent from zero, with an isotropic chemical shift in good agreement with the value in aqueous solution. This study illustrates how even very tiny chemical shift tensors can be extracted from the NMR spectra of quadrupolar nuclei using appropriate techniques.
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