Thallium nuclear properties

Sodium is unlike any other cation in its charge and radius. Thus, sodium must be followed by its own nuclear properties (18). Potassium can be replaced, in principle, by thallium(I) and cesium. Both are useful as they have suitable nuclei for NMR studies but thallium has additionally an absorption band at 214 nm which is very ligand-dependent, a readily observable fiuorescence, and a small temperature-independent paramagnetism which can cause marked shifts in the nuclear resonances of ligand nuclei. We (19) have aimed in the first instance to discover if thalhum replaces potassium eflFectively in enzymes. Table VII shows that it does. 

Radioactive metals can be used in radio-release methods for the determination of oxidizing agents in aqueous solutions. The decisive factors in the choice of the metal are the following the metal should not react with water, but should react with oxidizing agents to yield ions that do not form precipitates in aqueous media the metal should have a radionuclide with suitable nuclear properties. These conditions are met by thallium ( " TI) and silver ( ° Ag). 

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