1H NMR dipolar relaxation times and the derivation of internuclear distance
✍ Scribed by Liu, Maili ;Lindon, John C.
- Book ID
- 102657679
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 922 KB
- Volume
- 8
- Category
- Article
- ISSN
- 1043-7347
No coin nor oath required. For personal study only.
✦ Synopsis
The theory of nuclear spin relaxation via the dipole-dipole coupling mechanism is discussed. Various methods of measuring relaxation rates are described and shown to provide a means for measuring interhydrogen distances in molecules. The methods include the combined use of selective and biselective pulses to invert single resonances together with nonselective pulses The theory is given with applications from the literature. A modification of the methods-in which one resonance is left noninverted-is described, and some applications of this more efficient approach are shown. The distances obtained from such inversion-recovery relaxation rate measurements are compared with values measured from nuclear Overhauser effect build-up rates.
📜 SIMILAR VOLUMES
The usefulness of 'H bi-selective relaxation times ( 2 ' : ' ) and selective relaxation times (T,') for structure and conformation determination is emphasized. A pulse sequence has been devised which provides the apparent observed T : ' . The cross-relaxations (q,) or Fi, values are derived from the
## Abstract We applied the POST‐C7 DQ‐dipolar recoupling pulse sequence to the measurement of ^1^H–^1^H distances with high precision. The spectral resolution is enhanced by detecting the ^1^H magnetization via ^13^C signals. A least‐squares fitting of the build‐up curve of the transferred magnetiz
Recent developments in the mathematical solution of nuclear magnetic ( ) resonance NMR relaxation equations describing rotational motion allow investigators to determine correlation times, , on the nanosecond time scale. NMR rotational correlation equations for quadrupolar and dipolar relaxation can
## Abstract A relaxation method was applied to quinidine (1) where cross‐relaxations (σ~ij~) were obtained by ^1^H selective and biselective __T__~1~ measurements and correlation times for molecular reorientation (τ~c~) were evaluated from the frequency dependence of the non‐selective __T__~1.~ The
## Abstract The analysis of high‐frequency ^1^H and ^13^C NMR spectra and both ^1^H^1^H homonuclear and ^1^H^13^C heteronuclear chemical shift correlation experiments indicate that __N__‐propynlnormetazocine (NPMH^+^) is configurationally heterogeneous in solution, with the N‐equatorial isomer be