Improved Estimation of CSA–Dipolar Coupling Cross-Correlation Rates from Laboratory-Frame Relaxation Experiments
✍ Scribed by Ranajeet Ghose; James H Prestegard
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 149 KB
- Volume
- 134
- Category
- Article
- ISSN
- 1090-7807
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✦ Synopsis
We have investigated the underlying assumptions in estimating cross-correlation rates between chemical shift anisotropy (CSA) and dipolar coupling mechanisms in a scalar-coupled two-spin IS system, from laboratory frame relaxation experiments. It has been shown that for an arbitrary relaxation delay, the difference in relaxation rates of the individual components of an in-phase (or antiphase) doublet is not related to the CSA-dipolar coupling cross-correlation rate in a simple way. This is especially true in the case where the difference in the decay rates of the in-phase and antiphase terms of the density matrix becomes comparable to the magnitude of the scalar coupling between the two spins. Improved means of extracting cross-correlation rates in these cases are presented.