The solvent and field dependence of 59Co NMR linewidths
Abstract
The chemical shifts and linewidths of the 59Co resonances of six cobalt(III) complexes of low symmetry are discussed. Measurements at three different field strengths and in a variety of solvents are reported. Both the linewidths and their field dependence differ markedly in different solvents. The results are correlated with the hydrogen bonding abilities of the solvents. The field-independent part of the linewidth is attributed to quadrupolar relaxation and it is inferred that both the quadrupolar coupling constant and the correlation time vary with solvent. The field-dependent contribution is substantial in strongly hydrogen bonding solvents and small in weakly hydrogen bonding solvents indicating that the field dependence of 59Co relaxation times is associated with second coordination sphere interactions.
- Publication:
-
Journal of Magnetic Resonance
- Pub Date:
- 1983
- DOI:
- 10.1016/0022-2364(83)90163-4
- Bibcode:
- 1983JMagR..52..366A