Studies of an Isolated15N–15N Spin Pair. Off-Angle Fast-Sample-Spinning NMR and Self-Consistent-Field Calculations for Diazo Systems
✍ Scribed by Robin Challoner; Robin K. Harris; John A. Tossell
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 197 KB
- Volume
- 126
- Category
- Article
- ISSN
- 1090-7807
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✦ Synopsis
An off-magic-angle spinning study of the nonassociated molecular solid, doubly 15 N-labeled 5-methyl-2-diazobenzenesulphonic acid hydrochloride (I ) is reported. The validity of the off-magic-angle spinning approach under fast-spinning conditions is verified by average Hamiltonian theory. Ab initio SCF calculations were performed on the simpler molecule, C6 H5 N2 + , to provide the shielding parameters, the dipolar coupling between the two nitrogen nuclei, and the electric field gradient existing at both the alpha-nitrogen and beta-nitrogen sites. The calculated values are in good agreement with the shielding and effective dipolar coupling data elucidated in the present investigation, and with a previous study of the two singly 15 N-labeled isotopomers in which information concerning the electric field gradient at the alpha and beta sites was deduced.