Relaxation studies of carbonyl rhenium clusters. Part 2—relaxation mechanisms and estimation of the 13C chemical shielding anisotropy in the [Re3(μ-H)4(CO)10]− anion at low temperature
✍ Scribed by Tiziana Beringhelli; Giuseppe D'Alfonso; Henriette Molinari
- Publisher
- John Wiley and Sons
- Year
- 1986
- Tongue
- English
- Weight
- 483 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0749-1581
No coin nor oath required. For personal study only.
✦ Synopsis
Application of the non-selective inversion recovery
technique to 13C spectra of moderately enriched [Re,(p-H),(CO),]-indicates that relaxation times, at low temperatures, are strongly field dependent and decrease with increasing field strength. Measurements performed at 183K and at 20.15, 50.31 and 67.88 MHz indicate that chemical shielding anisotropy is dominant at higher fields, which dBers from the behavionr previously observed at room temperature where the main relaxation pathway is scalar coupling with the quadrupolar rhenium isotopes. The =C chemical shielding anisotropy was estimated to be in the range 476 f 40 ppm. Interactions with quadrnpolar rhenium also affect the hydrogen spin-spin relaxation times.