99Tc NMR Study of Tc(V) Solids
EMSL Project ID
18598
Abstract
Because of the wide variety of conditions and complexing agents found in radioactive wastes, technetium potentially exists in a multitude of interesting and novel chemical forms, both solid and liquid. The atomic coordinates of these compounds, if pure and crystalline, can be definitively and straightforwardly determined by x-ray crystallography, but this technique alone cannot provide all of the structure and bonding information usually desired, nor can it be applied in every case of prime interest, such as solution state species, mixtures of compounds, or amorphous powders. As a method for elucidating structure and bonding in inorganic and organometallic solids, magnetic resonance spectroscopy is second only to x-ray crystallography in importance and popularity, yet there has been only limited use of this approach to study Tc solids (exclusively pertechnetate salts), in spite of the favorable NMR properties of the 99Tc isotope and the applicability of the method to other diamagnetic oxidation states such as Tc(V) and Tc(III).
We propose to analyze several polycrystalline Tc(V) organometallic complexes by NMR spectroscopy. The NMR experiments will measure electric field gradient and chemical shift tensors of the 99Tc isotope and nuclei covalently bound to it. The experimental results will serve as the guide and reference for ab initio methods that can directly and accurately relate these electronic parameters to the electronic structure and bonding around the metal.
Project Details
Project type
Capability Research
Start Date
2006-04-17
End Date
2007-05-21
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members