Low Temperature 1H-, 19F-, and 31P-PGSE Diffusion Measurements. Applications to Cationic Alcohol Complexes
✍ Scribed by Eloísa Martínez-Viviente; Paul S. Pregosin
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- German
- Weight
- 174 KB
- Volume
- 86
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Abstract
The problems associated with low‐temperature pulsed‐gradient spin‐echo (PGSE) NMR diffusion measurements are discussed. The influence of convection is overcome by employing a coaxial insert inside a normal 5 mm NMR tube. By means of this configuration, correct diffusion constants and temperature‐independent hydrodynamic radii can be obtained. Low‐temperature ^1^H‐, ^19^F‐, and ^31^P‐PGSE measurements on unstable cationic alcohol complexes of palladium and tungsten (in MeOH and CH~2~Cl~2~) are reported. For W(Cp)(adamant‐1‐ol)(CO)~3~, a strong hydrogen bond between the alcohol OH group and the trifluoromethanesulfonate anion is demonstrated.