The diazo group as an example of an isolated nuclear spin pair. Nitrogen-15 rotational resonance
✍ Scribed by Robin Challoner; Robin K. Harris
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 662 KB
- Volume
- 228
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
✦ Synopsis
This solid-state nuclear magnetic resonance investigation is concerned with the 15N spin pair present in the non-associated molecular solid, 5-methyl-2-diazobcnzenesulphonic acid hydrochloride. The tSN spectrum is investigated under both magicangle and off-magic-angle conditions. For the magic-angle spinning case, when the isotropic shift difference of the two spins, or a submultiple thereof, precisely coincides with the frequency of sample rotation, spectral broadening is predicted. We observe unusually distinct and striking lineshape features for this compound under this rotational resonance condition from which we estimate a ~SN-lSN separation of 1.110 + 0.004/~. A simplified description of the rotational resonance phenomenon is presented. The off-magic-angle spinning experiment allows us to deduce the relative orientations of the shielding tensors and the dipolar interaction. The experimental shielding parameters are compared with qualitative theoretical prediction.