Tritium nuclear magnetic resonance spectroscopy. Part 11. Further consideration of referencing, isotope effects and coupling constants: Preparation of [3H]tetramethylsilane
✍ Scribed by James P. Bloxsidge; John A. Elvidge; John R. Jones; Ramachandra B. Mane; Manouchehr Saljoughian
- Publisher
- John Wiley and Sons
- Year
- 1979
- Tongue
- English
- Weight
- 459 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0749-1581
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Small discrepancies between ^3^H and ^1^H chemical shifts in organic compounds led to the finding that the ratio of Larmor frequencies ω~T~/ω~H~ depends on the carbon‐hydrogen bond hybridisation. The ‘best’ ratio for ghost referencing of ^3^H NMR spectra was then determined from measurements on purified partially tritiated TMS as 1.066639738±2 × 10^−9^. Some ^3^H isotope effects on chemical shifts are listed and the ^3^H isotope effect on the methylene geminal coupling constant in benzyl methyl sulphoxide is measured. Use of ^2^H in the measurement of ^2^J(HH) coupling constants has inherent disadvantages, overcome by use of ^3^H substitution.